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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 9c5beed5f5a6da5bd86c7dee6f8f803e8960e6a6 / . / 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>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]51 </ol>
52 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]53 <li><a href="#typesystem">Type System</a>
54 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]55 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]56 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]57 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]58 <li><a href="#t_floating">Floating Point Types</a></li>
59 <li><a href="#t_void">Void Type</a></li>
60 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]61 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]62 </ol>
63 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]64 <li><a href="#t_derived">Derived Types</a>
65 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]66 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]67 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]68 <li><a href="#t_function">Function Type</a></li>
69 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]70 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]71 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]72 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]73 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]74 </ol>
75 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]76 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]77 </ol>
78 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]79 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]80 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]81 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]82 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]83 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
84 <li><a href="#undefvalues">Undefined Values</a></li>
85 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]86 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]87 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]88 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]89 <li><a href="#othervalues">Other Values</a>
90 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]92 </ol>
93 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]94 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
95 <ol>
96 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]97 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
98 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]99 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
100 Global Variable</a></li>
101 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
102 Global Variable</a></li>
103 </ol>
104 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]105 <li><a href="#instref">Instruction Reference</a>
106 <ol>
107 <li><a href="#terminators">Terminator Instructions</a>
108 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]109 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
110 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]111 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
112 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]113 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]114 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]115 </ol>
116 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#binaryops">Binary Operations</a>
118 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]119 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]120 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]122 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]124 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]125 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
126 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
127 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]128 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
129 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
130 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]133 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
134 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]135 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
136 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
137 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]138 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]139 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]140 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]141 </ol>
142 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]143 <li><a href="#vectorops">Vector Operations</a>
144 <ol>
145 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
146 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
147 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]148 </ol>
149 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]150 <li><a href="#aggregateops">Aggregate Operations</a>
151 <ol>
152 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
153 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
154 </ol>
155 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]156 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]157 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]158 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
159 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
160 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]161 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
162 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
163 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]164 </ol>
165 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]166 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]167 <ol>
168 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
169 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
170 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]173 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
174 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
175 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
176 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]177 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
178 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]179 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]180 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]181 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]182 <li><a href="#otherops">Other Operations</a>
183 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]184 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
185 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]186 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]187 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]188 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]189 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]190 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]191 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]192 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]193 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]194 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]195 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]196 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
197 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]198 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
199 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]201 </ol>
202 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]203 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
204 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]205 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
206 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]210 <li><a href="#int_codegen">Code Generator Intrinsics</a>
211 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
213 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
215 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
216 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
217 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
218 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]221 <li><a href="#int_libc">Standard C Library Intrinsics</a>
222 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
224 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]228 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
229 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]231 </ol>
232 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]233 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]234 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]235 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]236 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
237 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]239 </ol>
240 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]241 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
242 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]243 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
244 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]248 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]249 </ol>
250 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]251 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]252 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]253 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]254 <ol>
255 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]256 </ol>
257 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]258 <li><a href="#int_atomics">Atomic intrinsics</a>
259 <ol>
260 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
261 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
262 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
263 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
264 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
265 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
266 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
267 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
268 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
269 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
270 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
271 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
272 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
273 </ol>
274 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]275 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]276 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]277 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]278 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]279 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]280 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]281 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]282 '<tt>llvm.trap</tt>' Intrinsic</a></li>
283 <li><a href="#int_stackprotector">
284 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]285 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]286 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]287 </ol>
288 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]289</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]290
291<div class="doc_author">
292 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
293 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]294</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]296<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]297<div class="doc_section"> <a name="abstract">Abstract </a></div>
298<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]299
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]300<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]301
302<p>This document is a reference manual for the LLVM assembly language. LLVM is
303 a Static Single Assignment (SSA) based representation that provides type
304 safety, low-level operations, flexibility, and the capability of representing
305 'all' high-level languages cleanly. It is the common code representation
306 used throughout all phases of the LLVM compilation strategy.</p>
307
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]308</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]309
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]310<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]311<div class="doc_section"> <a name="introduction">Introduction</a> </div>
312<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]313
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]314<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]315
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]316<p>The LLVM code representation is designed to be used in three different forms:
317 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
318 for fast loading by a Just-In-Time compiler), and as a human readable
319 assembly language representation. This allows LLVM to provide a powerful
320 intermediate representation for efficient compiler transformations and
321 analysis, while providing a natural means to debug and visualize the
322 transformations. The three different forms of LLVM are all equivalent. This
323 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]325<p>The LLVM representation aims to be light-weight and low-level while being
326 expressive, typed, and extensible at the same time. It aims to be a
327 "universal IR" of sorts, by being at a low enough level that high-level ideas
328 may be cleanly mapped to it (similar to how microprocessors are "universal
329 IR's", allowing many source languages to be mapped to them). By providing
330 type information, LLVM can be used as the target of optimizations: for
331 example, through pointer analysis, it can be proven that a C automatic
332 variable is never accessed outside of the current function... allowing it to
333 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]334
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]335</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]336
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]337<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]338<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]339
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]340<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]341
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]342<p>It is important to note that this document describes 'well formed' LLVM
343 assembly language. There is a difference between what the parser accepts and
344 what is considered 'well formed'. For example, the following instruction is
345 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]346
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]347<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]349%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]350</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]351</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]352
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]353<p>...because the definition of <tt>%x</tt> does not dominate all of its
354 uses. The LLVM infrastructure provides a verification pass that may be used
355 to verify that an LLVM module is well formed. This pass is automatically run
356 by the parser after parsing input assembly and by the optimizer before it
357 outputs bitcode. The violations pointed out by the verifier pass indicate
358 bugs in transformation passes or input to the parser.</p>
359
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]360</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]361
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]362<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]364<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]365<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]366<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]367
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]368<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]370<p>LLVM identifiers come in two basic types: global and local. Global
371 identifiers (functions, global variables) begin with the <tt>'@'</tt>
372 character. Local identifiers (register names, types) begin with
373 the <tt>'%'</tt> character. Additionally, there are three different formats
374 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]376<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]377 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]378 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
379 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
380 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
381 other characters in their names can be surrounded with quotes. Special
382 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
383 ASCII code for the character in hexadecimal. In this way, any character
384 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]385
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]386 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]387 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]389 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]390 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]391</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]392
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]393<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]394 don't need to worry about name clashes with reserved words, and the set of
395 reserved words may be expanded in the future without penalty. Additionally,
396 unnamed identifiers allow a compiler to quickly come up with a temporary
397 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]398
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]399<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]400 languages. There are keywords for different opcodes
401 ('<tt><a href="#i_add">add</a></tt>',
402 '<tt><a href="#i_bitcast">bitcast</a></tt>',
403 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
404 ('<tt><a href="#t_void">void</a></tt>',
405 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
406 reserved words cannot conflict with variable names, because none of them
407 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]408
409<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]410 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]412<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]413
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]414<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]415<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]416%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]417</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]418</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]419
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]420<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]422<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]423<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]424%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]425</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]426</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]428<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]429
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]430<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]431<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]432<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
433<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
434%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]435</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]436</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]438<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
439 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]441<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]443 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
445 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]446 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]448 <li>Unnamed temporaries are numbered sequentially</li>
449</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]450
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]451<p>...and it also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]452 demonstrating instructions, we will follow an instruction with a comment that
453 defines the type and name of value produced. Comments are shown in italic
454 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]456</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457
458<!-- *********************************************************************** -->
459<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
460<!-- *********************************************************************** -->
461
462<!-- ======================================================================= -->
463<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
464</div>
465
466<div class="doc_text">
467
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]468<p>LLVM programs are composed of "Module"s, each of which is a translation unit
469 of the input programs. Each module consists of functions, global variables,
470 and symbol table entries. Modules may be combined together with the LLVM
471 linker, which merges function (and global variable) definitions, resolves
472 forward declarations, and merges symbol table entries. Here is an example of
473 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]474
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]475<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]476<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]477<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
478 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]479
480<i>; External declaration of the puts function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]481<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]482
483<i>; Definition of main function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]484define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]485 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]486 %cast210 = <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]487 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]488
489 <i>; Call puts function to write out the string to stdout...</i>
490 <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]491 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]492 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]493 href="#i_ret">ret</a> i32 0<br>}<br>
494</pre>
495</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]497<p>This example is made up of a <a href="#globalvars">global variable</a> named
498 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
499 a <a href="#functionstructure">function definition</a> for
500 "<tt>main</tt>".</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]501
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]502<p>In general, a module is made up of a list of global values, where both
503 functions and global variables are global values. Global values are
504 represented by a pointer to a memory location (in this case, a pointer to an
505 array of char, and a pointer to a function), and have one of the
506 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]507
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]508</div>
509
510<!-- ======================================================================= -->
511<div class="doc_subsection">
512 <a name="linkage">Linkage Types</a>
513</div>
514
515<div class="doc_text">
516
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]517<p>All Global Variables and Functions have one of the following types of
518 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]519
520<dl>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]521 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]522 <dd>Global values with private linkage are only directly accessible by objects
523 in the current module. In particular, linking code into a module with an
524 private global value may cause the private to be renamed as necessary to
525 avoid collisions. Because the symbol is private to the module, all
526 references can be updated. This doesn't show up in any symbol table in the
527 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]528
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]529 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]530 <dd>Similar to private, but the symbol is passed through the assembler and
531 removed by the linker after evaluation.</dd>
532
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]533 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]534 <dd>Similar to private, but the value shows as a local symbol
535 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
536 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]539 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]540 into the object file corresponding to the LLVM module. They exist to
541 allow inlining and other optimizations to take place given knowledge of
542 the definition of the global, which is known to be somewhere outside the
543 module. Globals with <tt>available_externally</tt> linkage are allowed to
544 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
545 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]546
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]548 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]549 the same name when linkage occurs. This is typically used to implement
550 inline functions, templates, or other code which must be generated in each
551 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
552 allowed to be discarded.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]553
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]555 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
556 linkage, except that unreferenced <tt>common</tt> globals may not be
557 discarded. This is used for globals that may be emitted in multiple
558 translation units, but that are not guaranteed to be emitted into every
559 translation unit that uses them. One example of this is tentative
560 definitions in C, such as "<tt>int X;</tt>" at global scope.</dd>
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]561
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]562 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]563 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]564 that some targets may choose to emit different assembly sequences for them
565 for target-dependent reasons. This is used for globals that are declared
566 "weak" in C source code.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]567
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]569 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]570 pointer to array type. When two global variables with appending linkage
571 are linked together, the two global arrays are appended together. This is
572 the LLVM, typesafe, equivalent of having the system linker append together
573 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]574
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]576 <dd>The semantics of this linkage follow the ELF object file model: the symbol
577 is weak until linked, if not linked, the symbol becomes null instead of
578 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]579
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]582 <dd>Some languages allow differing globals to be merged, such as two functions
583 with different semantics. Other languages, such as <tt>C++</tt>, ensure
584 that only equivalent globals are ever merged (the "one definition rule" -
585 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
586 and <tt>weak_odr</tt> linkage types to indicate that the global will only
587 be merged with equivalent globals. These linkage types are otherwise the
588 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]589
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]591 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]592 visible, meaning that it participates in linkage and can be used to
593 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]594</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]595
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]596<p>The next two types of linkage are targeted for Microsoft Windows platform
597 only. They are designed to support importing (exporting) symbols from (to)
598 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]599
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]600<dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]601 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]602 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]603 or variable via a global pointer to a pointer that is set up by the DLL
604 exporting the symbol. On Microsoft Windows targets, the pointer name is
605 formed by combining <code>__imp_</code> and the function or variable
606 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]607
608 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]609 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]610 pointer to a pointer in a DLL, so that it can be referenced with the
611 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
612 name is formed by combining <code>__imp_</code> and the function or
613 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]614</dl>
615
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]616<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
617 another module defined a "<tt>.LC0</tt>" variable and was linked with this
618 one, one of the two would be renamed, preventing a collision. Since
619 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
620 declarations), they are accessible outside of the current module.</p>
621
622<p>It is illegal for a function <i>declaration</i> to have any linkage type
623 other than "externally visible", <tt>dllimport</tt>
624 or <tt>extern_weak</tt>.</p>
625
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]626<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]627 or <tt>weak_odr</tt> linkages.</p>
628
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]629</div>
630
631<!-- ======================================================================= -->
632<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]633 <a name="callingconv">Calling Conventions</a>
634</div>
635
636<div class="doc_text">
637
638<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]639 and <a href="#i_invoke">invokes</a> can all have an optional calling
640 convention specified for the call. The calling convention of any pair of
641 dynamic caller/callee must match, or the behavior of the program is
642 undefined. The following calling conventions are supported by LLVM, and more
643 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]644
645<dl>
646 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]647 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]648 specified) matches the target C calling conventions. This calling
649 convention supports varargs function calls and tolerates some mismatch in
650 the declared prototype and implemented declaration of the function (as
651 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]652
653 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]654 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]655 (e.g. by passing things in registers). This calling convention allows the
656 target to use whatever tricks it wants to produce fast code for the
657 target, without having to conform to an externally specified ABI
658 (Application Binary Interface). Implementations of this convention should
659 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
660 optimization</a> to be supported. This calling convention does not
661 support varargs and requires the prototype of all callees to exactly match
662 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]663
664 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]665 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]666 as possible under the assumption that the call is not commonly executed.
667 As such, these calls often preserve all registers so that the call does
668 not break any live ranges in the caller side. This calling convention
669 does not support varargs and requires the prototype of all callees to
670 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]671
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]672 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]673 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]674 target-specific calling conventions to be used. Target specific calling
675 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]676</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]677
678<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]679 support Pascal conventions or any other well-known target-independent
680 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]681
682</div>
683
684<!-- ======================================================================= -->
685<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]686 <a name="visibility">Visibility Styles</a>
687</div>
688
689<div class="doc_text">
690
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]691<p>All Global Variables and Functions have one of the following visibility
692 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]693
694<dl>
695 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]696 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]697 that the declaration is visible to other modules and, in shared libraries,
698 means that the declared entity may be overridden. On Darwin, default
699 visibility means that the declaration is visible to other modules. Default
700 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]701
702 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]703 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]704 object if they are in the same shared object. Usually, hidden visibility
705 indicates that the symbol will not be placed into the dynamic symbol
706 table, so no other module (executable or shared library) can reference it
707 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]708
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]709 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]710 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]711 the dynamic symbol table, but that references within the defining module
712 will bind to the local symbol. That is, the symbol cannot be overridden by
713 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]714</dl>
715
716</div>
717
718<!-- ======================================================================= -->
719<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]720 <a name="namedtypes">Named Types</a>
721</div>
722
723<div class="doc_text">
724
725<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]726 it easier to read the IR and make the IR more condensed (particularly when
727 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]728
729<div class="doc_code">
730<pre>
731%mytype = type { %mytype*, i32 }
732</pre>
733</div>
734
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]735<p>You may give a name to any <a href="#typesystem">type</a> except
736 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
737 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]738
739<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]740 and that you can therefore specify multiple names for the same type. This
741 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
742 uses structural typing, the name is not part of the type. When printing out
743 LLVM IR, the printer will pick <em>one name</em> to render all types of a
744 particular shape. This means that if you have code where two different
745 source types end up having the same LLVM type, that the dumper will sometimes
746 print the "wrong" or unexpected type. This is an important design point and
747 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]748
749</div>
750
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]751<!-- ======================================================================= -->
752<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]753 <a name="globalvars">Global Variables</a>
754</div>
755
756<div class="doc_text">
757
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]758<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]759 instead of run-time. Global variables may optionally be initialized, may
760 have an explicit section to be placed in, and may have an optional explicit
761 alignment specified. A variable may be defined as "thread_local", which
762 means that it will not be shared by threads (each thread will have a
763 separated copy of the variable). A variable may be defined as a global
764 "constant," which indicates that the contents of the variable
765 will <b>never</b> be modified (enabling better optimization, allowing the
766 global data to be placed in the read-only section of an executable, etc).
767 Note that variables that need runtime initialization cannot be marked
768 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]769
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]770<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
771 constant, even if the final definition of the global is not. This capability
772 can be used to enable slightly better optimization of the program, but
773 requires the language definition to guarantee that optimizations based on the
774 'constantness' are valid for the translation units that do not include the
775 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]776
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]777<p>As SSA values, global variables define pointer values that are in scope
778 (i.e. they dominate) all basic blocks in the program. Global variables
779 always define a pointer to their "content" type because they describe a
780 region of memory, and all memory objects in LLVM are accessed through
781 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]782
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]783<p>A global variable may be declared to reside in a target-specific numbered
784 address space. For targets that support them, address spaces may affect how
785 optimizations are performed and/or what target instructions are used to
786 access the variable. The default address space is zero. The address space
787 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]788
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]789<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]790 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]791
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]792<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]793 the alignment is set to zero, the alignment of the global is set by the
794 target to whatever it feels convenient. If an explicit alignment is
795 specified, the global is forced to have at least that much alignment. All
796 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]797
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]798<p>For example, the following defines a global in a numbered address space with
799 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]800
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]801<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]802<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]803@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]804</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]805</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]806
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]807</div>
808
809
810<!-- ======================================================================= -->
811<div class="doc_subsection">
812 <a name="functionstructure">Functions</a>
813</div>
814
815<div class="doc_text">
816
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]817<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
818 optional <a href="#linkage">linkage type</a>, an optional
819 <a href="#visibility">visibility style</a>, an optional
820 <a href="#callingconv">calling convention</a>, a return type, an optional
821 <a href="#paramattrs">parameter attribute</a> for the return type, a function
822 name, a (possibly empty) argument list (each with optional
823 <a href="#paramattrs">parameter attributes</a>), optional
824 <a href="#fnattrs">function attributes</a>, an optional section, an optional
825 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
826 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]827
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]828<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
829 optional <a href="#linkage">linkage type</a>, an optional
830 <a href="#visibility">visibility style</a>, an optional
831 <a href="#callingconv">calling convention</a>, a return type, an optional
832 <a href="#paramattrs">parameter attribute</a> for the return type, a function
833 name, a possibly empty list of arguments, an optional alignment, and an
834 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]835
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]836<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]837 (Control Flow Graph) for the function. Each basic block may optionally start
838 with a label (giving the basic block a symbol table entry), contains a list
839 of instructions, and ends with a <a href="#terminators">terminator</a>
840 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]841
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]842<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]843 executed on entrance to the function, and it is not allowed to have
844 predecessor basic blocks (i.e. there can not be any branches to the entry
845 block of a function). Because the block can have no predecessors, it also
846 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]847
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]848<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]849 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]850
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]851<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]852 the alignment is set to zero, the alignment of the function is set by the
853 target to whatever it feels convenient. If an explicit alignment is
854 specified, the function is forced to have at least that much alignment. All
855 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]856
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]857<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]858<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]859<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]860define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]861 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
862 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
863 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
864 [<a href="#gc">gc</a>] { ... }
865</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]866</div>
867
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]868</div>
869
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]870<!-- ======================================================================= -->
871<div class="doc_subsection">
872 <a name="aliasstructure">Aliases</a>
873</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]874
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]875<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]876
877<p>Aliases act as "second name" for the aliasee value (which can be either
878 function, global variable, another alias or bitcast of global value). Aliases
879 may have an optional <a href="#linkage">linkage type</a>, and an
880 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]881
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]882<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]883<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]884<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]885@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]886</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]887</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]888
889</div>
890
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]891<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]892<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]893
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]894<div class="doc_text">
895
896<p>The return type and each parameter of a function type may have a set of
897 <i>parameter attributes</i> associated with them. Parameter attributes are
898 used to communicate additional information about the result or parameters of
899 a function. Parameter attributes are considered to be part of the function,
900 not of the function type, so functions with different parameter attributes
901 can have the same function type.</p>
902
903<p>Parameter attributes are simple keywords that follow the type specified. If
904 multiple parameter attributes are needed, they are space separated. For
905 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]906
907<div class="doc_code">
908<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]909declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]910declare i32 @atoi(i8 zeroext)
911declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]912</pre>
913</div>
914
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]915<p>Note that any attributes for the function result (<tt>nounwind</tt>,
916 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]917
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]918<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]919
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]920<dl>
921 <dt><tt>zeroext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]922 <dd>This indicates to the code generator that the parameter or return value
923 should be zero-extended to a 32-bit value by the caller (for a parameter)
924 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]925
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]926 <dt><tt>signext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]927 <dd>This indicates to the code generator that the parameter or return value
928 should be sign-extended to a 32-bit value by the caller (for a parameter)
929 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]930
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]931 <dt><tt>inreg</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]932 <dd>This indicates that this parameter or return value should be treated in a
933 special target-dependent fashion during while emitting code for a function
934 call or return (usually, by putting it in a register as opposed to memory,
935 though some targets use it to distinguish between two different kinds of
936 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]937
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]938 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]939 <dd>This indicates that the pointer parameter should really be passed by value
940 to the function. The attribute implies that a hidden copy of the pointee
941 is made between the caller and the callee, so the callee is unable to
942 modify the value in the callee. This attribute is only valid on LLVM
943 pointer arguments. It is generally used to pass structs and arrays by
944 value, but is also valid on pointers to scalars. The copy is considered
945 to belong to the caller not the callee (for example,
946 <tt><a href="#readonly">readonly</a></tt> functions should not write to
947 <tt>byval</tt> parameters). This is not a valid attribute for return
948 values. The byval attribute also supports specifying an alignment with
949 the align attribute. This has a target-specific effect on the code
950 generator that usually indicates a desired alignment for the synthesized
951 stack slot.</dd>
952
953 <dt><tt>sret</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]954 <dd>This indicates that the pointer parameter specifies the address of a
955 structure that is the return value of the function in the source program.
956 This pointer must be guaranteed by the caller to be valid: loads and
957 stores to the structure may be assumed by the callee to not to trap. This
958 may only be applied to the first parameter. This is not a valid attribute
959 for return values. </dd>
960
961 <dt><tt>noalias</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]962 <dd>This indicates that the pointer does not alias any global or any other
963 parameter. The caller is responsible for ensuring that this is the
964 case. On a function return value, <tt>noalias</tt> additionally indicates
965 that the pointer does not alias any other pointers visible to the
966 caller. For further details, please see the discussion of the NoAlias
967 response in
968 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
969 analysis</a>.</dd>
970
971 <dt><tt>nocapture</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]972 <dd>This indicates that the callee does not make any copies of the pointer
973 that outlive the callee itself. This is not a valid attribute for return
974 values.</dd>
975
976 <dt><tt>nest</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates that the pointer parameter can be excised using the
978 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
979 attribute for return values.</dd>
980</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]981
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]982</div>
983
984<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]985<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]986 <a name="gc">Garbage Collector Names</a>
987</div>
988
989<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]990
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]991<p>Each function may specify a garbage collector name, which is simply a
992 string:</p>
993
994<div class="doc_code">
995<pre>
996define void @f() gc "name" { ...
997</pre>
998</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]999
1000<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1001 collector which will cause the compiler to alter its output in order to
1002 support the named garbage collection algorithm.</p>
1003
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1004</div>
1005
1006<!-- ======================================================================= -->
1007<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1008 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1009</div>
1010
1011<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1012
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1013<p>Function attributes are set to communicate additional information about a
1014 function. Function attributes are considered to be part of the function, not
1015 of the function type, so functions with different parameter attributes can
1016 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1017
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1018<p>Function attributes are simple keywords that follow the type specified. If
1019 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1020
1021<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1022<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1023define void @f() noinline { ... }
1024define void @f() alwaysinline { ... }
1025define void @f() alwaysinline optsize { ... }
1026define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1027</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1028</div>
1029
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1030<dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1031 <dt><tt>alwaysinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This attribute indicates that the inliner should attempt to inline this
1033 function into callers whenever possible, ignoring any active inlining size
1034 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1035
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1036 <dt><tt>noinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This attribute indicates that the inliner should never inline this
1038 function in any situation. This attribute may not be used together with
1039 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1040
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1041 <dt><tt>optsize</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This attribute suggests that optimization passes and code generator passes
1043 make choices that keep the code size of this function low, and otherwise
1044 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1045
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1046 <dt><tt>noreturn</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1047 <dd>This function attribute indicates that the function never returns
1048 normally. This produces undefined behavior at runtime if the function
1049 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1051 <dt><tt>nounwind</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052 <dd>This function attribute indicates that the function never returns with an
1053 unwind or exceptional control flow. If the function does unwind, its
1054 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1055
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1056 <dt><tt>readnone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1057 <dd>This attribute indicates that the function computes its result (or decides
1058 to unwind an exception) based strictly on its arguments, without
1059 dereferencing any pointer arguments or otherwise accessing any mutable
1060 state (e.g. memory, control registers, etc) visible to caller functions.
1061 It does not write through any pointer arguments
1062 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1063 changes any state visible to callers. This means that it cannot unwind
1064 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1065 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1066
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1067 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068 <dd>This attribute indicates that the function does not write through any
1069 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1070 arguments) or otherwise modify any state (e.g. memory, control registers,
1071 etc) visible to caller functions. It may dereference pointer arguments
1072 and read state that may be set in the caller. A readonly function always
1073 returns the same value (or unwinds an exception identically) when called
1074 with the same set of arguments and global state. It cannot unwind an
1075 exception by calling the <tt>C++</tt> exception throwing methods, but may
1076 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1077
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1078 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1079 <dd>This attribute indicates that the function should emit a stack smashing
1080 protector. It is in the form of a "canary"&mdash;a random value placed on
1081 the stack before the local variables that's checked upon return from the
1082 function to see if it has been overwritten. A heuristic is used to
1083 determine if a function needs stack protectors or not.<br>
1084<br>
1085 If a function that has an <tt>ssp</tt> attribute is inlined into a
1086 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1087 function will have an <tt>ssp</tt> attribute.</dd>
1088
1089 <dt><tt>sspreq</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1090 <dd>This attribute indicates that the function should <em>always</em> emit a
1091 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1092 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1093<br>
1094 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1095 function that doesn't have an <tt>sspreq</tt> attribute or which has
1096 an <tt>ssp</tt> attribute, then the resulting function will have
1097 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1098
1099 <dt><tt>noredzone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1100 <dd>This attribute indicates that the code generator should not use a red
1101 zone, even if the target-specific ABI normally permits it.</dd>
1102
1103 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1104 <dd>This attributes disables implicit floating point instructions.</dd>
1105
1106 <dt><tt>naked</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1107 <dd>This attribute disables prologue / epilogue emission for the function.
1108 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1109</dl>
1110
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1111</div>
1112
1113<!-- ======================================================================= -->
1114<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1115 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1116</div>
1117
1118<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1119
1120<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1121 the GCC "file scope inline asm" blocks. These blocks are internally
1122 concatenated by LLVM and treated as a single unit, but may be separated in
1123 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1124
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1125<div class="doc_code">
1126<pre>
1127module asm "inline asm code goes here"
1128module asm "more can go here"
1129</pre>
1130</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1131
1132<p>The strings can contain any character by escaping non-printable characters.
1133 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1134 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1135
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1136<p>The inline asm code is simply printed to the machine code .s file when
1137 assembly code is generated.</p>
1138
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1139</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1140
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1141<!-- ======================================================================= -->
1142<div class="doc_subsection">
1143 <a name="datalayout">Data Layout</a>
1144</div>
1145
1146<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1147
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1148<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1149 data is to be laid out in memory. The syntax for the data layout is
1150 simply:</p>
1151
1152<div class="doc_code">
1153<pre>
1154target datalayout = "<i>layout specification</i>"
1155</pre>
1156</div>
1157
1158<p>The <i>layout specification</i> consists of a list of specifications
1159 separated by the minus sign character ('-'). Each specification starts with
1160 a letter and may include other information after the letter to define some
1161 aspect of the data layout. The specifications accepted are as follows:</p>
1162
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1163<dl>
1164 <dt><tt>E</tt></dt>
1165 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1166 bits with the most significance have the lowest address location.</dd>
1167
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1168 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1169 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1170 the bits with the least significance have the lowest address
1171 location.</dd>
1172
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1173 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1174 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1175 <i>preferred</i> alignments. All sizes are in bits. Specifying
1176 the <i>pref</i> alignment is optional. If omitted, the
1177 preceding <tt>:</tt> should be omitted too.</dd>
1178
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1179 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1180 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1181 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1182
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1183 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1184 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1185 <i>size</i>.</dd>
1186
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1187 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1188 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1189 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1190 (double).</dd>
1191
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1192 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1193 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1194 <i>size</i>.</dd>
1195
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1196 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1197 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1198 <i>size</i>.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1199</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1200
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1201<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1202 default set of specifications which are then (possibly) overriden by the
1203 specifications in the <tt>datalayout</tt> keyword. The default specifications
1204 are given in this list:</p>
1205
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1206<ul>
1207 <li><tt>E</tt> - big endian</li>
1208 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1209 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1210 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1211 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1212 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1213 <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]1214 alignment of 64-bits</li>
1215 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1216 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1217 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1218 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1219 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1220 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1221</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1222
1223<p>When LLVM is determining the alignment for a given type, it uses the
1224 following rules:</p>
1225
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1226<ol>
1227 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1228 specification is used.</li>
1229
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1230 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1231 smallest integer type that is larger than the bitwidth of the sought type
1232 is used. If none of the specifications are larger than the bitwidth then
1233 the the largest integer type is used. For example, given the default
1234 specifications above, the i7 type will use the alignment of i8 (next
1235 largest) while both i65 and i256 will use the alignment of i64 (largest
1236 specified).</li>
1237
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1238 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1239 largest vector type that is smaller than the sought vector type will be
1240 used as a fall back. This happens because &lt;128 x double&gt; can be
1241 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1242</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1243
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1244</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1245
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1246<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1247<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1248<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1249
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1250<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1251
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1252<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1253 intermediate representation. Being typed enables a number of optimizations
1254 to be performed on the intermediate representation directly, without having
1255 to do extra analyses on the side before the transformation. A strong type
1256 system makes it easier to read the generated code and enables novel analyses
1257 and transformations that are not feasible to perform on normal three address
1258 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1259
1260</div>
1261
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1262<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1263<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1264Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1266<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1267
1268<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1269
1270<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1271 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1272 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1273 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1274 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1275 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1276 </tr>
1277 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1278 <td><a href="#t_floating">floating point</a></td>
1279 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1280 </tr>
1281 <tr>
1282 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1283 <td><a href="#t_integer">integer</a>,
1284 <a href="#t_floating">floating point</a>,
1285 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1286 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1287 <a href="#t_struct">structure</a>,
1288 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1289 <a href="#t_label">label</a>,
1290 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1291 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1292 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1293 <tr>
1294 <td><a href="#t_primitive">primitive</a></td>
1295 <td><a href="#t_label">label</a>,
1296 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1297 <a href="#t_floating">floating point</a>,
1298 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1299 </tr>
1300 <tr>
1301 <td><a href="#t_derived">derived</a></td>
1302 <td><a href="#t_integer">integer</a>,
1303 <a href="#t_array">array</a>,
1304 <a href="#t_function">function</a>,
1305 <a href="#t_pointer">pointer</a>,
1306 <a href="#t_struct">structure</a>,
1307 <a href="#t_pstruct">packed structure</a>,
1308 <a href="#t_vector">vector</a>,
1309 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1310 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1311 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1312 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1313</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1314
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1315<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1316 important. Values of these types are the only ones which can be produced by
1317 instructions, passed as arguments, or used as operands to instructions.</p>
1318
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1319</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1320
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1321<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1322<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1323
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1324<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1325
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1326<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1327 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1328
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1329</div>
1330
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1331<!-- _______________________________________________________________________ -->
1332<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1333
1334<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1335
1336<table>
1337 <tbody>
1338 <tr><th>Type</th><th>Description</th></tr>
1339 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1340 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1341 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1342 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1343 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1344 </tbody>
1345</table>
1346
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1347</div>
1348
1349<!-- _______________________________________________________________________ -->
1350<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1351
1352<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1353
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1354<h5>Overview:</h5>
1355<p>The void type does not represent any value and has no size.</p>
1356
1357<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1358<pre>
1359 void
1360</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1361
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1362</div>
1363
1364<!-- _______________________________________________________________________ -->
1365<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1366
1367<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1368
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1369<h5>Overview:</h5>
1370<p>The label type represents code labels.</p>
1371
1372<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1373<pre>
1374 label
1375</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1376
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1377</div>
1378
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1379<!-- _______________________________________________________________________ -->
1380<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1381
1382<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1383
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1384<h5>Overview:</h5>
1385<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1386 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1387 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1388
1389<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1390<pre>
1391 metadata
1392</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1393
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1394</div>
1395
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1396
1397<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1398<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1399
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1400<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1401
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1402<p>The real power in LLVM comes from the derived types in the system. This is
1403 what allows a programmer to represent arrays, functions, pointers, and other
1404 useful types. Note that these derived types may be recursive: For example,
1405 it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1406
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1407</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1409<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1410<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1411
1412<div class="doc_text">
1413
1414<h5>Overview:</h5>
1415<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1416 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1417 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1418
1419<h5>Syntax:</h5>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1420<pre>
1421 iN
1422</pre>
1423
1424<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1425 value.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1426
1427<h5>Examples:</h5>
1428<table class="layout">
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1429 <tr class="layout">
1430 <td class="left"><tt>i1</tt></td>
1431 <td class="left">a single-bit integer.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1432 </tr>
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1433 <tr class="layout">
1434 <td class="left"><tt>i32</tt></td>
1435 <td class="left">a 32-bit integer.</td>
1436 </tr>
1437 <tr class="layout">
1438 <td class="left"><tt>i1942652</tt></td>
1439 <td class="left">a really big integer of over 1 million bits.</td>
1440 </tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1441</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1442
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1443<p>Note that the code generator does not yet support large integer types to be
1444 used as function return types. The specific limit on how large a return type
1445 the code generator can currently handle is target-dependent; currently it's
1446 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1447
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1448</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1449
1450<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1451<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1453<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1454
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1455<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1456<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1457 sequentially in memory. The array type requires a size (number of elements)
1458 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1459
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1460<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1461<pre>
1462 [&lt;# elements&gt; x &lt;elementtype&gt;]
1463</pre>
1464
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1465<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1466 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1467
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1468<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1469<table class="layout">
1470 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1471 <td class="left"><tt>[40 x i32]</tt></td>
1472 <td class="left">Array of 40 32-bit integer values.</td>
1473 </tr>
1474 <tr class="layout">
1475 <td class="left"><tt>[41 x i32]</tt></td>
1476 <td class="left">Array of 41 32-bit integer values.</td>
1477 </tr>
1478 <tr class="layout">
1479 <td class="left"><tt>[4 x i8]</tt></td>
1480 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1481 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1482</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1483<p>Here are some examples of multidimensional arrays:</p>
1484<table class="layout">
1485 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1486 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1487 <td class="left">3x4 array of 32-bit integer values.</td>
1488 </tr>
1489 <tr class="layout">
1490 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1491 <td class="left">12x10 array of single precision floating point values.</td>
1492 </tr>
1493 <tr class="layout">
1494 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1495 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1496 </tr>
1497</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1498
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1499<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1500 length array. Normally, accesses past the end of an array are undefined in
1501 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1502 a special case, however, zero length arrays are recognized to be variable
1503 length. This allows implementation of 'pascal style arrays' with the LLVM
1504 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1505
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1506<p>Note that the code generator does not yet support large aggregate types to be
1507 used as function return types. The specific limit on how large an aggregate
1508 return type the code generator can currently handle is target-dependent, and
1509 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1510
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1511</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1512
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1513<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1514<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1515
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1516<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1517
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1518<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1519<p>The function type can be thought of as a function signature. It consists of
1520 a return type and a list of formal parameter types. The return type of a
1521 function type is a scalar type, a void type, or a struct type. If the return
1522 type is a struct type then all struct elements must be of first class types,
1523 and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1524
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1525<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1526<pre>
1527 &lt;returntype list&gt; (&lt;parameter list&gt;)
1528</pre>
1529
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1530<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1531 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1532 which indicates that the function takes a variable number of arguments.
1533 Variable argument functions can access their arguments with
1534 the <a href="#int_varargs">variable argument handling intrinsic</a>
1535 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1536 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1537
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1538<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1539<table class="layout">
1540 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1541 <td class="left"><tt>i32 (i32)</tt></td>
1542 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1543 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1544 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1545 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1546 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1547 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1548 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1549 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1550 <tt>float</tt>.
1551 </td>
1552 </tr><tr class="layout">
1553 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1554 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1555 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1556 which returns an integer. This is the signature for <tt>printf</tt> in
1557 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1558 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1559 </tr><tr class="layout">
1560 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1561 <td class="left">A function taking an <tt>i32</tt>, returning two
1562 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1563 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1564 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1565</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1566
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1567</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1568
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1569<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1570<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1571
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1572<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1573
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1574<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1575<p>The structure type is used to represent a collection of data members together
1576 in memory. The packing of the field types is defined to match the ABI of the
1577 underlying processor. The elements of a structure may be any type that has a
1578 size.</p>
1579
1580<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1581 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1582 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1583
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1584<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1585<pre>
1586 { &lt;type list&gt; }
1587</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1588
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1589<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1590<table class="layout">
1591 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1592 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1593 <td class="left">A triple of three <tt>i32</tt> values</td>
1594 </tr><tr class="layout">
1595 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1596 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1597 second element is a <a href="#t_pointer">pointer</a> to a
1598 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1599 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1600 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1601</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1602
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1603<p>Note that the code generator does not yet support large aggregate types to be
1604 used as function return types. The specific limit on how large an aggregate
1605 return type the code generator can currently handle is target-dependent, and
1606 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1607
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1608</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1609
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1610<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1611<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1612</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1613
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1614<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1615
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1616<h5>Overview:</h5>
1617<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1618 together in memory. There is no padding between fields. Further, the
1619 alignment of a packed structure is 1 byte. The elements of a packed
1620 structure may be any type that has a size.</p>
1621
1622<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1623 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1624 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1625
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1626<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1627<pre>
1628 &lt; { &lt;type list&gt; } &gt;
1629</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1630
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1631<h5>Examples:</h5>
1632<table class="layout">
1633 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1634 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1635 <td class="left">A triple of three <tt>i32</tt> values</td>
1636 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1637 <td class="left">
1638<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1639 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1640 second element is a <a href="#t_pointer">pointer</a> to a
1641 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1642 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1643 </tr>
1644</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1645
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1646</div>
1647
1648<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1649<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1650
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1651<div class="doc_text">
1652
1653<h5>Overview:</h5>
1654<p>As in many languages, the pointer type represents a pointer or reference to
1655 another object, which must live in memory. Pointer types may have an optional
1656 address space attribute defining the target-specific numbered address space
1657 where the pointed-to object resides. The default address space is zero.</p>
1658
1659<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1660 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1661
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1662<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1663<pre>
1664 &lt;type&gt; *
1665</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1666
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1667<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1668<table class="layout">
1669 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1670 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1671 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1672 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1673 </tr>
1674 <tr class="layout">
1675 <td class="left"><tt>i32 (i32 *) *</tt></td>
1676 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1677 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1678 <tt>i32</tt>.</td>
1679 </tr>
1680 <tr class="layout">
1681 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1682 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1683 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1684 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1685</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1686
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1687</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1688
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1689<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1690<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1691
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1692<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1693
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1694<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1695<p>A vector type is a simple derived type that represents a vector of elements.
1696 Vector types are used when multiple primitive data are operated in parallel
1697 using a single instruction (SIMD). A vector type requires a size (number of
1698 elements) and an underlying primitive data type. Vectors must have a power
1699 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1700 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1701
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1702<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1703<pre>
1704 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1705</pre>
1706
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1707<p>The number of elements is a constant integer value; elementtype may be any
1708 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1709
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1710<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1711<table class="layout">
1712 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1713 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1714 <td class="left">Vector of 4 32-bit integer values.</td>
1715 </tr>
1716 <tr class="layout">
1717 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1718 <td class="left">Vector of 8 32-bit floating-point values.</td>
1719 </tr>
1720 <tr class="layout">
1721 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1722 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1723 </tr>
1724</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1725
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1726<p>Note that the code generator does not yet support large vector types to be
1727 used as function return types. The specific limit on how large a vector
1728 return type codegen can currently handle is target-dependent; currently it's
1729 often a few times longer than a hardware vector register.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1730
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1731</div>
1732
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1733<!-- _______________________________________________________________________ -->
1734<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1735<div class="doc_text">
1736
1737<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1738<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1739 corresponds (for example) to the C notion of a forward declared structure
1740 type. In LLVM, opaque types can eventually be resolved to any type (not just
1741 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1742
1743<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1744<pre>
1745 opaque
1746</pre>
1747
1748<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1749<table class="layout">
1750 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1751 <td class="left"><tt>opaque</tt></td>
1752 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1753 </tr>
1754</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1755
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1756</div>
1757
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1758<!-- ======================================================================= -->
1759<div class="doc_subsection">
1760 <a name="t_uprefs">Type Up-references</a>
1761</div>
1762
1763<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1764
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1765<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1766<p>An "up reference" allows you to refer to a lexically enclosing type without
1767 requiring it to have a name. For instance, a structure declaration may
1768 contain a pointer to any of the types it is lexically a member of. Example
1769 of up references (with their equivalent as named type declarations)
1770 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1771
1772<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1773 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1774 { \2 }* %y = type { %y }*
1775 \1* %z = type %z*
1776</pre>
1777
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1778<p>An up reference is needed by the asmprinter for printing out cyclic types
1779 when there is no declared name for a type in the cycle. Because the
1780 asmprinter does not want to print out an infinite type string, it needs a
1781 syntax to handle recursive types that have no names (all names are optional
1782 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1783
1784<h5>Syntax:</h5>
1785<pre>
1786 \&lt;level&gt;
1787</pre>
1788
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1789<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1790
1791<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1792<table class="layout">
1793 <tr class="layout">
1794 <td class="left"><tt>\1*</tt></td>
1795 <td class="left">Self-referential pointer.</td>
1796 </tr>
1797 <tr class="layout">
1798 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1799 <td class="left">Recursive structure where the upref refers to the out-most
1800 structure.</td>
1801 </tr>
1802</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1803
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1804</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1805
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1806<!-- *********************************************************************** -->
1807<div class="doc_section"> <a name="constants">Constants</a> </div>
1808<!-- *********************************************************************** -->
1809
1810<div class="doc_text">
1811
1812<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1813 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1814
1815</div>
1816
1817<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1818<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1819
1820<div class="doc_text">
1821
1822<dl>
1823 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1824 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1825 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1826
1827 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1828 <dd>Standard integers (such as '4') are constants of
1829 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1830 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1831
1832 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1833 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1834 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1835 notation (see below). The assembler requires the exact decimal value of a
1836 floating-point constant. For example, the assembler accepts 1.25 but
1837 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1838 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1839
1840 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1841 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1842 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1843</dl>
1844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1845<p>The one non-intuitive notation for constants is the hexadecimal form of
1846 floating point constants. For example, the form '<tt>double
1847 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1848 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1849 constants are required (and the only time that they are generated by the
1850 disassembler) is when a floating point constant must be emitted but it cannot
1851 be represented as a decimal floating point number in a reasonable number of
1852 digits. For example, NaN's, infinities, and other special values are
1853 represented in their IEEE hexadecimal format so that assembly and disassembly
1854 do not cause any bits to change in the constants.</p>
1855
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1856<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1857 represented using the 16-digit form shown above (which matches the IEEE754
1858 representation for double); float values must, however, be exactly
1859 representable as IEE754 single precision. Hexadecimal format is always used
1860 for long double, and there are three forms of long double. The 80-bit format
1861 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1862 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1863 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1864 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1865 currently supported target uses this format. Long doubles will only work if
1866 they match the long double format on your target. All hexadecimal formats
1867 are big-endian (sign bit at the left).</p>
1868
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1869</div>
1870
1871<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1872<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]1873<a name="aggregateconstants"></a> <!-- old anchor -->
1874<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1875</div>
1876
1877<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1878
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1879<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1880 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1881
1882<dl>
1883 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1884 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1885 type definitions (a comma separated list of elements, surrounded by braces
1886 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1887 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1888 Structure constants must have <a href="#t_struct">structure type</a>, and
1889 the number and types of elements must match those specified by the
1890 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1891
1892 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1893 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1894 definitions (a comma separated list of elements, surrounded by square
1895 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1896 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1897 the number and types of elements must match those specified by the
1898 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1899
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1900 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1901 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1902 definitions (a comma separated list of elements, surrounded by
1903 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1904 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1905 have <a href="#t_vector">vector type</a>, and the number and types of
1906 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1907
1908 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1909 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1910 value to zero of <em>any</em> type, including scalar and aggregate types.
1911 This is often used to avoid having to print large zero initializers
1912 (e.g. for large arrays) and is always exactly equivalent to using explicit
1913 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]1914
1915 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]1916 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1917 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1918 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1919 be interpreted as part of the instruction stream, metadata is a place to
1920 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1921</dl>
1922
1923</div>
1924
1925<!-- ======================================================================= -->
1926<div class="doc_subsection">
1927 <a name="globalconstants">Global Variable and Function Addresses</a>
1928</div>
1929
1930<div class="doc_text">
1931
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1932<p>The addresses of <a href="#globalvars">global variables</a>
1933 and <a href="#functionstructure">functions</a> are always implicitly valid
1934 (link-time) constants. These constants are explicitly referenced when
1935 the <a href="#identifiers">identifier for the global</a> is used and always
1936 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1937 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1938
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1939<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1940<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1941@X = global i32 17
1942@Y = global i32 42
1943@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1944</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1945</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1946
1947</div>
1948
1949<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1950<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1951<div class="doc_text">
1952
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1953<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
1954 specific value. Undefined values may be of any type and be used anywhere a
1955 constant is permitted.</p>
1956
1957<p>Undefined values indicate to the compiler that the program is well defined no
1958 matter what value is used, giving the compiler more freedom to optimize.</p>
1959
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1960</div>
1961
1962<!-- ======================================================================= -->
1963<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1964</div>
1965
1966<div class="doc_text">
1967
1968<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1969 to be used as constants. Constant expressions may be of
1970 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
1971 operation that does not have side effects (e.g. load and call are not
1972 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1973
1974<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1975 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1976 <dd>Truncate a constant to another type. The bit size of CST must be larger
1977 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1978
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1979 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1980 <dd>Zero extend a constant to another type. The bit size of CST must be
1981 smaller or equal to the bit size of TYPE. Both types must be
1982 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1983
1984 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1985 <dd>Sign extend a constant to another type. The bit size of CST must be
1986 smaller or equal to the bit size of TYPE. Both types must be
1987 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1988
1989 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1990 <dd>Truncate a floating point constant to another floating point type. The
1991 size of CST must be larger than the size of TYPE. Both types must be
1992 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1993
1994 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1995 <dd>Floating point extend a constant to another type. The size of CST must be
1996 smaller or equal to the size of TYPE. Both types must be floating
1997 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1998
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1999 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2000 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2001 constant. TYPE must be a scalar or vector integer type. CST must be of
2002 scalar or vector floating point type. Both CST and TYPE must be scalars,
2003 or vectors of the same number of elements. If the value won't fit in the
2004 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2005
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2006 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2007 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2008 constant. TYPE must be a scalar or vector integer type. CST must be of
2009 scalar or vector floating point type. Both CST and TYPE must be scalars,
2010 or vectors of the same number of elements. If the value won't fit in the
2011 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2012
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2013 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2014 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2015 constant. TYPE must be a scalar or vector floating point type. CST must be
2016 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2017 vectors of the same number of elements. If the value won't fit in the
2018 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2019
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2020 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2021 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2022 constant. TYPE must be a scalar or vector floating point type. CST must be
2023 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2024 vectors of the same number of elements. If the value won't fit in the
2025 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2026
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2027 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2028 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2029 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2030 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2031 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2032
2033 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2034 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2035 type. CST must be of integer type. The CST value is zero extended,
2036 truncated, or unchanged to make it fit in a pointer size. This one is
2037 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2038
2039 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2040 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2041 are the same as those for the <a href="#i_bitcast">bitcast
2042 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2043
2044 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2045 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2046 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2047 instruction, the index list may have zero or more indexes, which are
2048 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2049
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2050 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2051 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2052
2053 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2054 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2055
2056 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2057 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2058
2059 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2060 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2061 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2062
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2063 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2064 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2065 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2066
2067 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2068 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2069 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2070
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2071 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2072 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2073 be any of the <a href="#binaryops">binary</a>
2074 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2075 on operands are the same as those for the corresponding instruction
2076 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2077</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2078
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2079</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2080
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2081<!-- ======================================================================= -->
2082<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2083</div>
2084
2085<div class="doc_text">
2086
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2087<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2088 stream without affecting the behaviour of the program. There are two
2089 metadata primitives, strings and nodes. All metadata has the
2090 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2091 point ('<tt>!</tt>').</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2092
2093<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2094 any character by escaping non-printable characters with "\xx" where "xx" is
2095 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2096
2097<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2098 (a comma separated list of elements, surrounded by braces and preceeded by an
2099 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2100 10}</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2101
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2102<p>A metadata node will attempt to track changes to the values it holds. In the
2103 event that a value is deleted, it will be replaced with a typeless
2104 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckycb337992009-05-10 20:57:05 +0000[diff] [blame]2105
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2106<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2107 the program that isn't available in the instructions, or that isn't easily
2108 computable. Similarly, the code generator may expect a certain metadata
2109 format to be used to express debugging information.</p>
2110
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2111</div>
2112
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2113<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2114<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2115<!-- *********************************************************************** -->
2116
2117<!-- ======================================================================= -->
2118<div class="doc_subsection">
2119<a name="inlineasm">Inline Assembler Expressions</a>
2120</div>
2121
2122<div class="doc_text">
2123
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2124<p>LLVM supports inline assembler expressions (as opposed
2125 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2126 a special value. This value represents the inline assembler as a string
2127 (containing the instructions to emit), a list of operand constraints (stored
2128 as a string), and a flag that indicates whether or not the inline asm
2129 expression has side effects. An example inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2130
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2131<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2132<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2133i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2134</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2135</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2137<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2138 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2139 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2140
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2141<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2142<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2143%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]2144</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2145</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2146
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2147<p>Inline asms with side effects not visible in the constraint list must be
2148 marked as having side effects. This is done through the use of the
2149 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2150
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2151<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2152<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2153call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2154</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2155</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2156
2157<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2158 documented here. Constraints on what can be done (e.g. duplication, moving,
2159 etc need to be documented). This is probably best done by reference to
2160 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2161
2162</div>
2163
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2164
2165<!-- *********************************************************************** -->
2166<div class="doc_section">
2167 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2168</div>
2169<!-- *********************************************************************** -->
2170
2171<p>LLVM has a number of "magic" global variables that contain data that affect
2172code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2173of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2174section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2175by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2176
2177<!-- ======================================================================= -->
2178<div class="doc_subsection">
2179<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2180</div>
2181
2182<div class="doc_text">
2183
2184<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2185href="#linkage_appending">appending linkage</a>. This array contains a list of
2186pointers to global variables and functions which may optionally have a pointer
2187cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2188
2189<pre>
2190 @X = global i8 4
2191 @Y = global i32 123
2192
2193 @llvm.used = appending global [2 x i8*] [
2194 i8* @X,
2195 i8* bitcast (i32* @Y to i8*)
2196 ], section "llvm.metadata"
2197</pre>
2198
2199<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2200compiler, assembler, and linker are required to treat the symbol as if there is
2201a reference to the global that it cannot see. For example, if a variable has
2202internal linkage and no references other than that from the <tt>@llvm.used</tt>
2203list, it cannot be deleted. This is commonly used to represent references from
2204inline asms and other things the compiler cannot "see", and corresponds to
2205"attribute((used))" in GNU C.</p>
2206
2207<p>On some targets, the code generator must emit a directive to the assembler or
2208object file to prevent the assembler and linker from molesting the symbol.</p>
2209
2210</div>
2211
2212<!-- ======================================================================= -->
2213<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2214<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2215</div>
2216
2217<div class="doc_text">
2218
2219<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2220<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2221touching the symbol. On targets that support it, this allows an intelligent
2222linker to optimize references to the symbol without being impeded as it would be
2223by <tt>@llvm.used</tt>.</p>
2224
2225<p>This is a rare construct that should only be used in rare circumstances, and
2226should not be exposed to source languages.</p>
2227
2228</div>
2229
2230<!-- ======================================================================= -->
2231<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2232<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2233</div>
2234
2235<div class="doc_text">
2236
2237<p>TODO: Describe this.</p>
2238
2239</div>
2240
2241<!-- ======================================================================= -->
2242<div class="doc_subsection">
2243<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2244</div>
2245
2246<div class="doc_text">
2247
2248<p>TODO: Describe this.</p>
2249
2250</div>
2251
2252
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2253<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2254<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2255<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2256
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2257<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2258
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2259<p>The LLVM instruction set consists of several different classifications of
2260 instructions: <a href="#terminators">terminator
2261 instructions</a>, <a href="#binaryops">binary instructions</a>,
2262 <a href="#bitwiseops">bitwise binary instructions</a>,
2263 <a href="#memoryops">memory instructions</a>, and
2264 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2266</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2267
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2268<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2269<div class="doc_subsection"> <a name="terminators">Terminator
2270Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2271
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2272<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2273
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2274<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2275 in a program ends with a "Terminator" instruction, which indicates which
2276 block should be executed after the current block is finished. These
2277 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2278 control flow, not values (the one exception being the
2279 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2280
2281<p>There are six different terminator instructions: the
2282 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2283 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2284 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2285 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2286 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2287 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2288
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2289</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2291<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2292<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2293Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2294
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2295<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2297<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2298<pre>
2299 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]2300 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2301</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2303<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2304<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2305 a value) from a function back to the caller.</p>
2306
2307<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2308 value and then causes control flow, and one that just causes control flow to
2309 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2311<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2312<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2313 return value. The type of the return value must be a
2314 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2315
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2316<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2317 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2318 value or a return value with a type that does not match its type, or if it
2319 has a void return type and contains a '<tt>ret</tt>' instruction with a
2320 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2323<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2324 the calling function's context. If the caller is a
2325 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2326 instruction after the call. If the caller was an
2327 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2328 the beginning of the "normal" destination block. If the instruction returns
2329 a value, that value shall set the call or invoke instruction's return
2330 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2331
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2332<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2333<pre>
2334 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2335 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2336 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2337</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2338
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2339<p>Note that the code generator does not yet fully support large
2340 return values. The specific sizes that are currently supported are
2341 dependent on the target. For integers, on 32-bit targets the limit
2342 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2343 For aggregate types, the current limits are dependent on the element
2344 types; for example targets are often limited to 2 total integer
2345 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2346
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2347</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2348<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2349<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2350
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2351<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2352
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2353<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2354<pre>
2355 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]2356</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2357
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2358<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2359<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2360 different basic block in the current function. There are two forms of this
2361 instruction, corresponding to a conditional branch and an unconditional
2362 branch.</p>
2363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2364<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2365<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2366 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2367 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2368 target.</p>
2369
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2370<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2371<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2372 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2373 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2374 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2376<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2377<pre>
2378Test:
2379 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2380 br i1 %cond, label %IfEqual, label %IfUnequal
2381IfEqual:
2382 <a href="#i_ret">ret</a> i32 1
2383IfUnequal:
2384 <a href="#i_ret">ret</a> i32 0
2385</pre>
2386
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2387</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2389<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2390<div class="doc_subsubsection">
2391 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2392</div>
2393
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2394<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2395
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2396<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2397<pre>
2398 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2399</pre>
2400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2401<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2402<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2403 several different places. It is a generalization of the '<tt>br</tt>'
2404 instruction, allowing a branch to occur to one of many possible
2405 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2406
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2408<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2409 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2410 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2411 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2412
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2413<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2414<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2415 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2416 is searched for the given value. If the value is found, control flow is
2417 transfered to the corresponding destination; otherwise, control flow is
2418 transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2419
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2420<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2421<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2422 <tt>switch</tt> instruction, this instruction may be code generated in
2423 different ways. For example, it could be generated as a series of chained
2424 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2425
2426<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2427<pre>
2428 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2429 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2430 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2431
2432 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2433 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2434
2435 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2436 switch i32 %val, label %otherwise [ i32 0, label %onzero
2437 i32 1, label %onone
2438 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2439</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2440
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2441</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2442
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2443<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2444<div class="doc_subsubsection">
2445 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2446</div>
2447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2448<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2449
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2450<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2451<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2452 &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]2453 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2454</pre>
2455
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2456<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2457<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2458 function, with the possibility of control flow transfer to either the
2459 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2460 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2461 control flow will return to the "normal" label. If the callee (or any
2462 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2463 instruction, control is interrupted and continued at the dynamically nearest
2464 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2465
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2466<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2467<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2469<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2470 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2471 convention</a> the call should use. If none is specified, the call
2472 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2473
2474 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2475 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2476 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2477
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2478 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2479 function value being invoked. In most cases, this is a direct function
2480 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2481 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2482
2483 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2484 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2485
2486 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2487 signature argument types. If the function signature indicates the
2488 function accepts a variable number of arguments, the extra arguments can
2489 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2490
2491 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2492 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2493
2494 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2495 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2496
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2497 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2498 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2499 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2500</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2501
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2502<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2503<p>This instruction is designed to operate as a standard
2504 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2505 primary difference is that it establishes an association with a label, which
2506 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2507
2508<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2509 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2510 exception. Additionally, this is important for implementation of
2511 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2512
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2513<p>For the purposes of the SSA form, the definition of the value returned by the
2514 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2515 block to the "normal" label. If the callee unwinds then no return value is
2516 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2517
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2518<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2519<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2520 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2521 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2522 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2523 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2524</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2525
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2526</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2527
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2528<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2529
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2530<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2531Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2532
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2533<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2534
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2535<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2536<pre>
2537 unwind
2538</pre>
2539
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2540<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2541<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2542 at the first callee in the dynamic call stack which used
2543 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2544 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2545
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2546<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2547<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2548 immediately halt. The dynamic call stack is then searched for the
2549 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2550 Once found, execution continues at the "exceptional" destination block
2551 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2552 instruction in the dynamic call chain, undefined behavior results.</p>
2553
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2554</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2555
2556<!-- _______________________________________________________________________ -->
2557
2558<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2559Instruction</a> </div>
2560
2561<div class="doc_text">
2562
2563<h5>Syntax:</h5>
2564<pre>
2565 unreachable
2566</pre>
2567
2568<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2569<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2570 instruction is used to inform the optimizer that a particular portion of the
2571 code is not reachable. This can be used to indicate that the code after a
2572 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2573
2574<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2575<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2576
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2577</div>
2578
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2579<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2580<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2581
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2582<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2583
2584<p>Binary operators are used to do most of the computation in a program. They
2585 require two operands of the same type, execute an operation on them, and
2586 produce a single value. The operands might represent multiple data, as is
2587 the case with the <a href="#t_vector">vector</a> data type. The result value
2588 has the same type as its operands.</p>
2589
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2590<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2591
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2592</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2593
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2594<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2595<div class="doc_subsubsection">
2596 <a name="i_add">'<tt>add</tt>' Instruction</a>
2597</div>
2598
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2599<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2600
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2601<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2602<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2603 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2604 &lt;result&gt; = signed add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2605 &lt;result&gt; = unsigned add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2606 &lt;result&gt; = unsigned signed 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]2607</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2608
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2609<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2610<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2611
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2612<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2613<p>The two arguments to the '<tt>add</tt>' instruction must
2614 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2615 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2616
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2617<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2618<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2619
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2620<p>If the sum has unsigned overflow, the result returned is the mathematical
2621 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2622
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2623<p>Because LLVM integers use a two's complement representation, this instruction
2624 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2625
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2626<p>If the <tt>signed</tt> and/or <tt>unsigned</tt> keywords are present,
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2627 the result value of the <tt>add</tt> is undefined if signed and/or unsigned
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2628 overflow, respectively, occurs.</p>
2629
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2630<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2631<pre>
2632 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2633</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2634
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2635</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2636
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2637<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2638<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2639 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2640</div>
2641
2642<div class="doc_text">
2643
2644<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2645<pre>
2646 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2647</pre>
2648
2649<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2650<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2651
2652<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2653<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2654 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2655 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2656
2657<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2658<p>The value produced is the floating point sum of the two operands.</p>
2659
2660<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2661<pre>
2662 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2663</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2664
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2665</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2666
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2667<!-- _______________________________________________________________________ -->
2668<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2669 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2670</div>
2671
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2672<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2673
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2674<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2675<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2676 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2677 &lt;result&gt; = signed sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2678 &lt;result&gt; = unsigned sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2679 &lt;result&gt; = unsigned signed 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]2680</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2681
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2682<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2683<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2684 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2685
2686<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2687 '<tt>neg</tt>' instruction present in most other intermediate
2688 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2689
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2690<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2691<p>The two arguments to the '<tt>sub</tt>' instruction must
2692 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2693 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2694
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2695<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2696<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2697
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2698<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2699 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2700 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2701
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2702<p>Because LLVM integers use a two's complement representation, this instruction
2703 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2704
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2705<p>If the <tt>signed</tt> and/or <tt>unsigned</tt> keywords are present,
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2706 the result value of the <tt>sub</tt> is undefined if signed and/or unsigned
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2707 overflow, respectively, occurs.</p>
2708
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2709<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2710<pre>
2711 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2712 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2713</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2714
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2715</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2716
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2717<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2718<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2719 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2720</div>
2721
2722<div class="doc_text">
2723
2724<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2725<pre>
2726 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2727</pre>
2728
2729<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2730<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2731 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2732
2733<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2734 '<tt>fneg</tt>' instruction present in most other intermediate
2735 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2736
2737<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2738<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2739 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2740 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2741
2742<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2743<p>The value produced is the floating point difference of the two operands.</p>
2744
2745<h5>Example:</h5>
2746<pre>
2747 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2748 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2749</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2750
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2751</div>
2752
2753<!-- _______________________________________________________________________ -->
2754<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2755 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2756</div>
2757
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2758<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2759
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2760<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2761<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2762 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2763 &lt;result&gt; = signed mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2764 &lt;result&gt; = unsigned mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2765 &lt;result&gt; = unsigned signed 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]2766</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2768<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2769<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2770
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2771<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2772<p>The two arguments to the '<tt>mul</tt>' instruction must
2773 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2774 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2775
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2776<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2777<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2778
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2779<p>If the result of the multiplication has unsigned overflow, the result
2780 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2781 width of the result.</p>
2782
2783<p>Because LLVM integers use a two's complement representation, and the result
2784 is the same width as the operands, this instruction returns the correct
2785 result for both signed and unsigned integers. If a full product
2786 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2787 be sign-extended or zero-extended as appropriate to the width of the full
2788 product.</p>
2789
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2790<p>If the <tt>signed</tt> and/or <tt>unsigned</tt> keywords are present,
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2791 the result value of the <tt>mul</tt> is undefined if signed and/or unsigned
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2792 overflow, respectively, occurs.</p>
2793
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2794<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2795<pre>
2796 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2797</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2798
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2799</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2800
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2801<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2802<div class="doc_subsubsection">
2803 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2804</div>
2805
2806<div class="doc_text">
2807
2808<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2809<pre>
2810 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2811</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2812
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2813<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2814<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2815
2816<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2817<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2818 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2819 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2820
2821<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2822<p>The value produced is the floating point product of the two operands.</p>
2823
2824<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2825<pre>
2826 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2827</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2828
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2829</div>
2830
2831<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2832<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2833</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2834
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2835<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2836
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2837<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2838<pre>
2839 &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]2840</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2841
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2842<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2843<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2844
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2845<h5>Arguments:</h5>
2846<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2847 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2848 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2849
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2850<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2851<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2852
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2853<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2854 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2855
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2856<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2857
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2858<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2859<pre>
2860 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2861</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2862
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2863</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2864
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2865<!-- _______________________________________________________________________ -->
2866<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2867</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2868
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2869<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2870
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2871<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2872<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2873 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2874 &lt;result&gt; = exact 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]2875</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2876
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2877<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2878<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2879
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2880<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2881<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2882 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2883 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2884
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2885<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2886<p>The value produced is the signed integer quotient of the two operands rounded
2887 towards zero.</p>
2888
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2889<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2890 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2891
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2892<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2893 undefined behavior; this is a rare case, but can occur, for example, by doing
2894 a 32-bit division of -2147483648 by -1.</p>
2895
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame^]2896<p>If the <tt>exact</tt> keyword is present, the result value of the
2897 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2898 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2899
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2900<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2901<pre>
2902 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2903</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2904
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2905</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2906
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2907<!-- _______________________________________________________________________ -->
2908<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2909Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2910
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2911<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2912
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2913<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2914<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2915 &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]2916</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2917
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2918<h5>Overview:</h5>
2919<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2920
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2921<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2922<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2923 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2924 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2925
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2926<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2927<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2928
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2929<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2930<pre>
2931 &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]2932</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2933
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2934</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2935
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2936<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2937<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2938</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2939
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2940<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2941
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2942<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2943<pre>
2944 &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]2945</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2946
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2947<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2948<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
2949 division of its two arguments.</p>
2950
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2951<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2952<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2953 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2954 values. Both arguments must have identical types.</p>
2955
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2956<h5>Semantics:</h5>
2957<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2958 This instruction always performs an unsigned division to get the
2959 remainder.</p>
2960
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2961<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2962 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2963
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2964<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2965
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2966<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967<pre>
2968 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2969</pre>
2970
2971</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2972
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2973<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2974<div class="doc_subsubsection">
2975 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2976</div>
2977
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2978<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2979
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2980<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2981<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2982 &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]2983</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2984
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2985<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2986<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
2987 division of its two operands. This instruction can also take
2988 <a href="#t_vector">vector</a> versions of the values in which case the
2989 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2990
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2991<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2992<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2993 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2994 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2995
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2996<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2997<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2998 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2999 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3000 a value. For more information about the difference,
3001 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3002 Math Forum</a>. For a table of how this is implemented in various languages,
3003 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3004 Wikipedia: modulo operation</a>.</p>
3005
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3006<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3007 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3008
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3009<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3010 Overflow also leads to undefined behavior; this is a rare case, but can
3011 occur, for example, by taking the remainder of a 32-bit division of
3012 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3013 lets srem be implemented using instructions that return both the result of
3014 the division and the remainder.)</p>
3015
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3016<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3017<pre>
3018 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3019</pre>
3020
3021</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3022
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3023<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3024<div class="doc_subsubsection">
3025 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3026
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3027<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3028
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3029<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3030<pre>
3031 &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]3032</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3033
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3034<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3035<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3036 its two operands.</p>
3037
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3038<h5>Arguments:</h5>
3039<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3040 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3041 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3042
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3043<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3044<p>This instruction returns the <i>remainder</i> of a division. The remainder
3045 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3046
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3047<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3048<pre>
3049 &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]3050</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3051
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3052</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3053
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3054<!-- ======================================================================= -->
3055<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3056Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3057
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3058<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3059
3060<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3061 program. They are generally very efficient instructions and can commonly be
3062 strength reduced from other instructions. They require two operands of the
3063 same type, execute an operation on them, and produce a single value. The
3064 resulting value is the same type as its operands.</p>
3065
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3066</div>
3067
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3068<!-- _______________________________________________________________________ -->
3069<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3070Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3071
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3072<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3073
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3074<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3075<pre>
3076 &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]3077</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3078
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3079<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3080<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3081 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3082
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3083<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3084<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3085 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3086 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3087
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3088<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3089<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3090 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3091 is (statically or dynamically) negative or equal to or larger than the number
3092 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3093 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3094 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3095
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3096<h5>Example:</h5>
3097<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3098 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3099 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3100 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3101 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3102 &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]3103</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3104
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3105</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3106
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3107<!-- _______________________________________________________________________ -->
3108<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3109Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3110
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3111<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3112
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3113<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3114<pre>
3115 &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]3116</pre>
3117
3118<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3119<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3120 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3121
3122<h5>Arguments:</h5>
3123<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3124 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3125 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3126
3127<h5>Semantics:</h5>
3128<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3129 significant bits of the result will be filled with zero bits after the shift.
3130 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3131 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3132 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3133 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3134
3135<h5>Example:</h5>
3136<pre>
3137 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3138 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3139 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3140 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3141 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3142 &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]3143</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3144
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3145</div>
3146
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3147<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3148<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3149Instruction</a> </div>
3150<div class="doc_text">
3151
3152<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3153<pre>
3154 &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]3155</pre>
3156
3157<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3158<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3159 operand shifted to the right a specified number of bits with sign
3160 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3161
3162<h5>Arguments:</h5>
3163<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3164 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3165 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3166
3167<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3168<p>This instruction always performs an arithmetic shift right operation, The
3169 most significant bits of the result will be filled with the sign bit
3170 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3171 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3172 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3173 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3174
3175<h5>Example:</h5>
3176<pre>
3177 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3178 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3179 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3180 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3181 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3182 &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]3183</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3184
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3185</div>
3186
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3187<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3188<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3189Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3191<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3192
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3193<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3194<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3195 &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]3196</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3197
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3199<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3200 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3201
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3202<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3203<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3204 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3205 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3206
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3207<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3208<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3209
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3210<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3211 <tbody>
3212 <tr>
3213 <td>In0</td>
3214 <td>In1</td>
3215 <td>Out</td>
3216 </tr>
3217 <tr>
3218 <td>0</td>
3219 <td>0</td>
3220 <td>0</td>
3221 </tr>
3222 <tr>
3223 <td>0</td>
3224 <td>1</td>
3225 <td>0</td>
3226 </tr>
3227 <tr>
3228 <td>1</td>
3229 <td>0</td>
3230 <td>0</td>
3231 </tr>
3232 <tr>
3233 <td>1</td>
3234 <td>1</td>
3235 <td>1</td>
3236 </tr>
3237 </tbody>
3238</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3239
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3240<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3241<pre>
3242 &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]3243 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3244 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3245</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3246</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3247<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3248<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3249
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3250<div class="doc_text">
3251
3252<h5>Syntax:</h5>
3253<pre>
3254 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3255</pre>
3256
3257<h5>Overview:</h5>
3258<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3259 two operands.</p>
3260
3261<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3262<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3263 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3264 values. Both arguments must have identical types.</p>
3265
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3266<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3267<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3268
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3269<table border="1" cellspacing="0" cellpadding="4">
3270 <tbody>
3271 <tr>
3272 <td>In0</td>
3273 <td>In1</td>
3274 <td>Out</td>
3275 </tr>
3276 <tr>
3277 <td>0</td>
3278 <td>0</td>
3279 <td>0</td>
3280 </tr>
3281 <tr>
3282 <td>0</td>
3283 <td>1</td>
3284 <td>1</td>
3285 </tr>
3286 <tr>
3287 <td>1</td>
3288 <td>0</td>
3289 <td>1</td>
3290 </tr>
3291 <tr>
3292 <td>1</td>
3293 <td>1</td>
3294 <td>1</td>
3295 </tr>
3296 </tbody>
3297</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3298
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3299<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3300<pre>
3301 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3302 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3303 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3304</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3306</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3308<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3309<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3310Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3311
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3312<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3313
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3314<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3315<pre>
3316 &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]3317</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3318
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3319<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3320<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3321 its two operands. The <tt>xor</tt> is used to implement the "one's
3322 complement" operation, which is the "~" operator in C.</p>
3323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3324<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3325<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3326 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3327 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3329<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3330<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3331
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3332<table border="1" cellspacing="0" cellpadding="4">
3333 <tbody>
3334 <tr>
3335 <td>In0</td>
3336 <td>In1</td>
3337 <td>Out</td>
3338 </tr>
3339 <tr>
3340 <td>0</td>
3341 <td>0</td>
3342 <td>0</td>
3343 </tr>
3344 <tr>
3345 <td>0</td>
3346 <td>1</td>
3347 <td>1</td>
3348 </tr>
3349 <tr>
3350 <td>1</td>
3351 <td>0</td>
3352 <td>1</td>
3353 </tr>
3354 <tr>
3355 <td>1</td>
3356 <td>1</td>
3357 <td>0</td>
3358 </tr>
3359 </tbody>
3360</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3361
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3362<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363<pre>
3364 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3365 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3366 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3367 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3368</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3369
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3370</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3371
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3372<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3373<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3374 <a name="vectorops">Vector Operations</a>
3375</div>
3376
3377<div class="doc_text">
3378
3379<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3380 target-independent manner. These instructions cover the element-access and
3381 vector-specific operations needed to process vectors effectively. While LLVM
3382 does directly support these vector operations, many sophisticated algorithms
3383 will want to use target-specific intrinsics to take full advantage of a
3384 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3385
3386</div>
3387
3388<!-- _______________________________________________________________________ -->
3389<div class="doc_subsubsection">
3390 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3391</div>
3392
3393<div class="doc_text">
3394
3395<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3396<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3397 &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]3398</pre>
3399
3400<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3401<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3402 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3403
3404
3405<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3406<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3407 of <a href="#t_vector">vector</a> type. The second operand is an index
3408 indicating the position from which to extract the element. The index may be
3409 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3410
3411<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3412<p>The result is a scalar of the same type as the element type of
3413 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3414 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3415 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3416
3417<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3418<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3419 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3420</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3421
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3422</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3423
3424<!-- _______________________________________________________________________ -->
3425<div class="doc_subsubsection">
3426 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3427</div>
3428
3429<div class="doc_text">
3430
3431<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3432<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3433 &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]3434</pre>
3435
3436<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3437<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3438 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3439
3440<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3441<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3442 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3443 whose type must equal the element type of the first operand. The third
3444 operand is an index indicating the position at which to insert the value.
3445 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3446
3447<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3448<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3449 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3450 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3451 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3452
3453<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3454<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3455 %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]3456</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3457
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3458</div>
3459
3460<!-- _______________________________________________________________________ -->
3461<div class="doc_subsubsection">
3462 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3463</div>
3464
3465<div class="doc_text">
3466
3467<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3468<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3469 &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]3470</pre>
3471
3472<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3473<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3474 from two input vectors, returning a vector with the same element type as the
3475 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3476
3477<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3478<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3479 with types that match each other. The third argument is a shuffle mask whose
3480 element type is always 'i32'. The result of the instruction is a vector
3481 whose length is the same as the shuffle mask and whose element type is the
3482 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3483
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3484<p>The shuffle mask operand is required to be a constant vector with either
3485 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3486
3487<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3488<p>The elements of the two input vectors are numbered from left to right across
3489 both of the vectors. The shuffle mask operand specifies, for each element of
3490 the result vector, which element of the two input vectors the result element
3491 gets. The element selector may be undef (meaning "don't care") and the
3492 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3493
3494<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3495<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3496 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3497 &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]3498 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3499 &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]3500 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3501 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3502 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3503 &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]3504</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3505
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3506</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3507
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3508<!-- ======================================================================= -->
3509<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3510 <a name="aggregateops">Aggregate Operations</a>
3511</div>
3512
3513<div class="doc_text">
3514
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3515<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3516
3517</div>
3518
3519<!-- _______________________________________________________________________ -->
3520<div class="doc_subsubsection">
3521 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3522</div>
3523
3524<div class="doc_text">
3525
3526<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3527<pre>
3528 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3529</pre>
3530
3531<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3533 or array element from an aggregate value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3534
3535<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3536<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3537 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3538 operands are constant indices to specify which value to extract in a similar
3539 manner as indices in a
3540 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3541
3542<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3543<p>The result is the value at the position in the aggregate specified by the
3544 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3545
3546<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3547<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3548 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3549</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3550
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3551</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3552
3553<!-- _______________________________________________________________________ -->
3554<div class="doc_subsubsection">
3555 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3556</div>
3557
3558<div class="doc_text">
3559
3560<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3561<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3562 &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]3563</pre>
3564
3565<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3566<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3567 array element in an aggregate.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3568
3569
3570<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3571<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3572 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3573 second operand is a first-class value to insert. The following operands are
3574 constant indices indicating the position at which to insert the value in a
3575 similar manner as indices in a
3576 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3577 value to insert must have the same type as the value identified by the
3578 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3579
3580<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3581<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3582 that of <tt>val</tt> except that the value at the position specified by the
3583 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3584
3585<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3586<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3587 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3588</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3589
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3590</div>
3591
3592
3593<!-- ======================================================================= -->
3594<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3595 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3596</div>
3597
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3598<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3599
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600<p>A key design point of an SSA-based representation is how it represents
3601 memory. In LLVM, no memory locations are in SSA form, which makes things
3602 very simple. This section describes how to read, write, allocate, and free
3603 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3604
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3605</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3606
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3607<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3608<div class="doc_subsubsection">
3609 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3610</div>
3611
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3612<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3613
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3614<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3615<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3616 &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]3617</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3618
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3619<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3620<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3621 returns a pointer to it. The object is always allocated in the generic
3622 address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3623
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3624<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3625<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3626 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3627 system and returns a pointer of the appropriate type to the program. If
3628 "NumElements" is specified, it is the number of elements allocated, otherwise
3629 "NumElements" is defaulted to be one. If a constant alignment is specified,
3630 the value result of the allocation is guaranteed to be aligned to at least
3631 that boundary. If not specified, or if zero, the target can choose to align
3632 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3633
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3634<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3635
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3636<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3637<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3638 pointer is returned. The result of a zero byte allocation is undefined. The
3639 result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3640
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3641<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3642<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3643 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3644
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3645 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3646 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3647 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3648 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3649 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3650</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3651
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3652<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3653
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3654</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3655
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3656<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3657<div class="doc_subsubsection">
3658 <a name="i_free">'<tt>free</tt>' Instruction</a>
3659</div>
3660
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3661<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3663<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3664<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3665 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3666</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3668<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3669<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3670 to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3671
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3672<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3674 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3676<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3677<p>Access to the memory pointed to by the pointer is no longer defined after
3678 this instruction executes. If the pointer is null, the operation is a
3679 noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3680
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3681<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3682<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3683 %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]3684 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3685</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3686
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3687</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3688
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3689<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3690<div class="doc_subsubsection">
3691 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3692</div>
3693
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3694<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3696<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3697<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3698 &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]3699</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3700
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3701<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3702<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3703 currently executing function, to be automatically released when this function
3704 returns to its caller. The object is always allocated in the generic address
3705 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3706
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3707<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3708<p>The '<tt>alloca</tt>' instruction
3709 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3710 runtime stack, returning a pointer of the appropriate type to the program.
3711 If "NumElements" is specified, it is the number of elements allocated,
3712 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3713 specified, the value result of the allocation is guaranteed to be aligned to
3714 at least that boundary. If not specified, or if zero, the target can choose
3715 to align the allocation on any convenient boundary compatible with the
3716 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3717
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3718<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3719
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3720<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]3721<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3722 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3723 memory is automatically released when the function returns. The
3724 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3725 variables that must have an address available. When the function returns
3726 (either with the <tt><a href="#i_ret">ret</a></tt>
3727 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3728 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3729
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3730<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3731<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3732 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3733 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3734 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3735 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3736</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3737
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3738</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3739
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3740<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3741<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3742Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3743
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3744<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3745
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3746<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3747<pre>
3748 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3749 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3750</pre>
3751
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3752<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3753<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3754
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3755<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3756<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3757 from which to load. The pointer must point to
3758 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3759 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3760 number or order of execution of this <tt>load</tt> with other
3761 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3762 instructions. </p>
3763
3764<p>The optional constant "align" argument specifies the alignment of the
3765 operation (that is, the alignment of the memory address). A value of 0 or an
3766 omitted "align" argument means that the operation has the preferential
3767 alignment for the target. It is the responsibility of the code emitter to
3768 ensure that the alignment information is correct. Overestimating the
3769 alignment results in an undefined behavior. Underestimating the alignment may
3770 produce less efficient code. An alignment of 1 is always safe.</p>
3771
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3772<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3773<p>The location of memory pointed to is loaded. If the value being loaded is of
3774 scalar type then the number of bytes read does not exceed the minimum number
3775 of bytes needed to hold all bits of the type. For example, loading an
3776 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3777 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3778 is undefined if the value was not originally written using a store of the
3779 same type.</p>
3780
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3781<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3782<pre>
3783 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3784 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3785 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3786</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3787
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3788</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3789
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3790<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3791<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3792Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3793
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3794<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3795
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3796<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3797<pre>
3798 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3799 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]3800</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3801
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3802<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3803<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3804
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3805<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3806<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3807 and an address at which to store it. The type of the
3808 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3809 the <a href="#t_firstclass">first class</a> type of the
3810 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3811 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3812 or order of execution of this <tt>store</tt> with other
3813 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3814 instructions.</p>
3815
3816<p>The optional constant "align" argument specifies the alignment of the
3817 operation (that is, the alignment of the memory address). A value of 0 or an
3818 omitted "align" argument means that the operation has the preferential
3819 alignment for the target. It is the responsibility of the code emitter to
3820 ensure that the alignment information is correct. Overestimating the
3821 alignment results in an undefined behavior. Underestimating the alignment may
3822 produce less efficient code. An alignment of 1 is always safe.</p>
3823
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3824<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3826 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3827 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3828 does not exceed the minimum number of bytes needed to hold all bits of the
3829 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3830 writing a value of a type like <tt>i20</tt> with a size that is not an
3831 integral number of bytes, it is unspecified what happens to the extra bits
3832 that do not belong to the type, but they will typically be overwritten.</p>
3833
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3834<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3835<pre>
3836 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3837 store i32 3, i32* %ptr <i>; yields {void}</i>
3838 %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]3839</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3840
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3841</div>
3842
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3843<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3844<div class="doc_subsubsection">
3845 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3846</div>
3847
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3848<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3849
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3850<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3851<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3852 &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]3853</pre>
3854
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3855<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3856<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3857 subelement of an aggregate data structure. It performs address calculation
3858 only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3859
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3860<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3861<p>The first argument is always a pointer, and forms the basis of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3862 calculation. The remaining arguments are indices, that indicate which of the
3863 elements of the aggregate object are indexed. The interpretation of each
3864 index is dependent on the type being indexed into. The first index always
3865 indexes the pointer value given as the first argument, the second index
3866 indexes a value of the type pointed to (not necessarily the value directly
3867 pointed to, since the first index can be non-zero), etc. The first type
3868 indexed into must be a pointer value, subsequent types can be arrays, vectors
3869 and structs. Note that subsequent types being indexed into can never be
3870 pointers, since that would require loading the pointer before continuing
3871 calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3872
3873<p>The type of each index argument depends on the type it is indexing into.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3874 When indexing into a (packed) structure, only <tt>i32</tt> integer
3875 <b>constants</b> are allowed. When indexing into an array, pointer or
3876 vector, integers of any width are allowed (also non-constants).</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3877
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3878<p>For example, let's consider a C code fragment and how it gets compiled to
3879 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3880
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3881<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3882<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3883struct RT {
3884 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3885 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3886 char C;
3887};
3888struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3889 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3890 double Y;
3891 struct RT Z;
3892};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3893
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3894int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3895 return &amp;s[1].Z.B[5][13];
3896}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3897</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3898</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3899
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3900<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3901
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3902<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3903<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3904%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3905%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3906
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3907define i32* %foo(%ST* %s) {
3908entry:
3909 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3910 ret i32* %reg
3911}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3912</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3913</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3914
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3915<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3916<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3917 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3918 }</tt>' type, a structure. The second index indexes into the third element
3919 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3920 i8 }</tt>' type, another structure. The third index indexes into the second
3921 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3922 array. The two dimensions of the array are subscripted into, yielding an
3923 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3924 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3925
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3926<p>Note that it is perfectly legal to index partially through a structure,
3927 returning a pointer to an inner element. Because of this, the LLVM code for
3928 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3929
3930<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3931 define i32* %foo(%ST* %s) {
3932 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3933 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3934 %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]3935 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3936 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3937 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3938 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3939</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3940
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3941<p>The getelementptr instruction is often confusing. For some more insight into
3942 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3943
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3944<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3945<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3946 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3947 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3948 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3949 %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]3950 <i>; yields i8*:eptr</i>
3951 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]3952 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]3953 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3954</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3955
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3956</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3957
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3958<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3959<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3960</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3961
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3962<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3963
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3964<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3965 which all take a single operand and a type. They perform various bit
3966 conversions on the operand.</p>
3967
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3968</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3969
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3970<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3971<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3972 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3973</div>
3974<div class="doc_text">
3975
3976<h5>Syntax:</h5>
3977<pre>
3978 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3979</pre>
3980
3981<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3982<p>The '<tt>trunc</tt>' instruction truncates its operand to the
3983 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3984
3985<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3986<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3987 be an <a href="#t_integer">integer</a> type, and a type that specifies the
3988 size and type of the result, which must be
3989 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
3990 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
3991 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3992
3993<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3994<p>The '<tt>trunc</tt>' instruction truncates the high order bits
3995 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
3996 source size must be larger than the destination size, <tt>trunc</tt> cannot
3997 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3998
3999<h5>Example:</h5>
4000<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4001 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4002 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4003 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4004</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4005
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4006</div>
4007
4008<!-- _______________________________________________________________________ -->
4009<div class="doc_subsubsection">
4010 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4011</div>
4012<div class="doc_text">
4013
4014<h5>Syntax:</h5>
4015<pre>
4016 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4017</pre>
4018
4019<h5>Overview:</h5>
4020<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4021 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4022
4023
4024<h5>Arguments:</h5>
4025<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4026 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4027 also be of <a href="#t_integer">integer</a> type. The bit size of the
4028 <tt>value</tt> must be smaller than the bit size of the destination type,
4029 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4030
4031<h5>Semantics:</h5>
4032<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4033 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4034
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4035<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]4036
4037<h5>Example:</h5>
4038<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4039 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4040 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4041</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4042
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4043</div>
4044
4045<!-- _______________________________________________________________________ -->
4046<div class="doc_subsubsection">
4047 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4048</div>
4049<div class="doc_text">
4050
4051<h5>Syntax:</h5>
4052<pre>
4053 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4054</pre>
4055
4056<h5>Overview:</h5>
4057<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4058
4059<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4060<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4061 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4062 also be of <a href="#t_integer">integer</a> type. The bit size of the
4063 <tt>value</tt> must be smaller than the bit size of the destination type,
4064 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4065
4066<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4067<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4068 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4069 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4070
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4071<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]4072
4073<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4074<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4075 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4076 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4077</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4078
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4079</div>
4080
4081<!-- _______________________________________________________________________ -->
4082<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4083 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4084</div>
4085
4086<div class="doc_text">
4087
4088<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4089<pre>
4090 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4091</pre>
4092
4093<h5>Overview:</h5>
4094<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4095 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4096
4097<h5>Arguments:</h5>
4098<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4099 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4100 to cast it to. The size of <tt>value</tt> must be larger than the size of
4101 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4102 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4103
4104<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4105<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4106 <a href="#t_floating">floating point</a> type to a smaller
4107 <a href="#t_floating">floating point</a> type. If the value cannot fit
4108 within the destination type, <tt>ty2</tt>, then the results are
4109 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4110
4111<h5>Example:</h5>
4112<pre>
4113 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4114 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4115</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4116
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4117</div>
4118
4119<!-- _______________________________________________________________________ -->
4120<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4121 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4122</div>
4123<div class="doc_text">
4124
4125<h5>Syntax:</h5>
4126<pre>
4127 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4128</pre>
4129
4130<h5>Overview:</h5>
4131<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4132 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4133
4134<h5>Arguments:</h5>
4135<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4136 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4137 a <a href="#t_floating">floating point</a> type to cast it to. The source
4138 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4139
4140<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4141<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4142 <a href="#t_floating">floating point</a> type to a larger
4143 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4144 used to make a <i>no-op cast</i> because it always changes bits. Use
4145 <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]4146
4147<h5>Example:</h5>
4148<pre>
4149 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4150 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4151</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4152
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4153</div>
4154
4155<!-- _______________________________________________________________________ -->
4156<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4157 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4158</div>
4159<div class="doc_text">
4160
4161<h5>Syntax:</h5>
4162<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4163 &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]4164</pre>
4165
4166<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4167<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4168 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4169
4170<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4171<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4172 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4173 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4174 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4175 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4176
4177<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4178<p>The '<tt>fptoui</tt>' instruction converts its
4179 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4180 towards zero) unsigned integer value. If the value cannot fit
4181 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4182
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4183<h5>Example:</h5>
4184<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4185 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4186 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4187 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4188</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4189
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4190</div>
4191
4192<!-- _______________________________________________________________________ -->
4193<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4194 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4195</div>
4196<div class="doc_text">
4197
4198<h5>Syntax:</h5>
4199<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4200 &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]4201</pre>
4202
4203<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4204<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4205 <a href="#t_floating">floating point</a> <tt>value</tt> to
4206 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4207
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4208<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4209<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4210 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4211 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4212 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4213 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4214
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4215<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4216<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4217 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4218 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4219 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4220
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4221<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4222<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4223 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4224 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4225 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4226</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4227
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4228</div>
4229
4230<!-- _______________________________________________________________________ -->
4231<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4232 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4233</div>
4234<div class="doc_text">
4235
4236<h5>Syntax:</h5>
4237<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4238 &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]4239</pre>
4240
4241<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4242<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4244
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4245<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4246<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4247 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4248 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4249 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4250 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4251
4252<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4253<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4254 integer quantity and converts it to the corresponding floating point
4255 value. If the value cannot fit in the floating point value, the results are
4256 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4257
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4258<h5>Example:</h5>
4259<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4260 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4261 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4262</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4263
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4264</div>
4265
4266<!-- _______________________________________________________________________ -->
4267<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4268 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4269</div>
4270<div class="doc_text">
4271
4272<h5>Syntax:</h5>
4273<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4274 &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]4275</pre>
4276
4277<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4278<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4279 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4280
4281<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4282<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4283 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4284 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4285 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4286 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4287
4288<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4289<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4290 quantity and converts it to the corresponding floating point value. If the
4291 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4292
4293<h5>Example:</h5>
4294<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4295 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4296 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4297</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4298
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4299</div>
4300
4301<!-- _______________________________________________________________________ -->
4302<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4303 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4304</div>
4305<div class="doc_text">
4306
4307<h5>Syntax:</h5>
4308<pre>
4309 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4310</pre>
4311
4312<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4313<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4314 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4315
4316<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4317<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4318 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4319 <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]4320
4321<h5>Semantics:</h5>
4322<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4323 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4324 truncating or zero extending that value to the size of the integer type. If
4325 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4326 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4327 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4328 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4329
4330<h5>Example:</h5>
4331<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4332 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4333 %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]4334</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4335
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4336</div>
4337
4338<!-- _______________________________________________________________________ -->
4339<div class="doc_subsubsection">
4340 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4341</div>
4342<div class="doc_text">
4343
4344<h5>Syntax:</h5>
4345<pre>
4346 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4347</pre>
4348
4349<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4350<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4351 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4352
4353<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4354<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355 value to cast, and a type to cast it to, which must be a
4356 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4357
4358<h5>Semantics:</h5>
4359<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4360 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4361 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4362 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4363 than the size of a pointer then a zero extension is done. If they are the
4364 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4365
4366<h5>Example:</h5>
4367<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4368 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4369 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4370 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4371</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4372
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4373</div>
4374
4375<!-- _______________________________________________________________________ -->
4376<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4377 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4378</div>
4379<div class="doc_text">
4380
4381<h5>Syntax:</h5>
4382<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4383 &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]4384</pre>
4385
4386<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4387<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4388 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4389
4390<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4391<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4392 non-aggregate first class value, and a type to cast it to, which must also be
4393 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4394 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4395 identical. If the source type is a pointer, the destination type must also be
4396 a pointer. This instruction supports bitwise conversion of vectors to
4397 integers and to vectors of other types (as long as they have the same
4398 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4399
4400<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4401<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4402 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4403 this conversion. The conversion is done as if the <tt>value</tt> had been
4404 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4405 be converted to other pointer types with this instruction. To convert
4406 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4407 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4408
4409<h5>Example:</h5>
4410<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4411 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4412 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4413 %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]4414</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4415
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4416</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4417
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4418<!-- ======================================================================= -->
4419<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4420
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4421<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4422
4423<p>The instructions in this category are the "miscellaneous" instructions, which
4424 defy better classification.</p>
4425
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4426</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4427
4428<!-- _______________________________________________________________________ -->
4429<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4430</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4431
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4432<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4433
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4434<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4435<pre>
4436 &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]4437</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4438
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4439<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4441 boolean values based on comparison of its two integer, integer vector, or
4442 pointer operands.</p>
4443
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4444<h5>Arguments:</h5>
4445<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4446 the condition code indicating the kind of comparison to perform. It is not a
4447 value, just a keyword. The possible condition code are:</p>
4448
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4449<ol>
4450 <li><tt>eq</tt>: equal</li>
4451 <li><tt>ne</tt>: not equal </li>
4452 <li><tt>ugt</tt>: unsigned greater than</li>
4453 <li><tt>uge</tt>: unsigned greater or equal</li>
4454 <li><tt>ult</tt>: unsigned less than</li>
4455 <li><tt>ule</tt>: unsigned less or equal</li>
4456 <li><tt>sgt</tt>: signed greater than</li>
4457 <li><tt>sge</tt>: signed greater or equal</li>
4458 <li><tt>slt</tt>: signed less than</li>
4459 <li><tt>sle</tt>: signed less or equal</li>
4460</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4461
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4462<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4463 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4464 typed. They must also be identical types.</p>
4465
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4466<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4467<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4468 condition code given as <tt>cond</tt>. The comparison performed always yields
4469 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4470 result, as follows:</p>
4471
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4472<ol>
4473 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4474 <tt>false</tt> otherwise. No sign interpretation is necessary or
4475 performed.</li>
4476
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4477 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4478 <tt>false</tt> otherwise. No sign interpretation is necessary or
4479 performed.</li>
4480
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4481 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4482 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4483
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4484 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4485 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4486 to <tt>op2</tt>.</li>
4487
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4488 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4489 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4490
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4491 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4492 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4493
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4494 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4495 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4496
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4497 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4499 to <tt>op2</tt>.</li>
4500
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4501 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4502 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4503
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4504 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4505 <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]4506</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4507
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4508<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4509 values are compared as if they were integers.</p>
4510
4511<p>If the operands are integer vectors, then they are compared element by
4512 element. The result is an <tt>i1</tt> vector with the same number of elements
4513 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4514
4515<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4516<pre>
4517 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4518 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4519 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4520 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4521 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4522 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4523</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4524
4525<p>Note that the code generator does not yet support vector types with
4526 the <tt>icmp</tt> instruction.</p>
4527
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4528</div>
4529
4530<!-- _______________________________________________________________________ -->
4531<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4532</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4533
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4534<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4535
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4536<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4537<pre>
4538 &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]4539</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4540
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4541<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4542<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4543 values based on comparison of its operands.</p>
4544
4545<p>If the operands are floating point scalars, then the result type is a boolean
4546(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4547
4548<p>If the operands are floating point vectors, then the result type is a vector
4549 of boolean with the same number of elements as the operands being
4550 compared.</p>
4551
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4552<h5>Arguments:</h5>
4553<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4554 the condition code indicating the kind of comparison to perform. It is not a
4555 value, just a keyword. The possible condition code are:</p>
4556
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4557<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4558 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4559 <li><tt>oeq</tt>: ordered and equal</li>
4560 <li><tt>ogt</tt>: ordered and greater than </li>
4561 <li><tt>oge</tt>: ordered and greater than or equal</li>
4562 <li><tt>olt</tt>: ordered and less than </li>
4563 <li><tt>ole</tt>: ordered and less than or equal</li>
4564 <li><tt>one</tt>: ordered and not equal</li>
4565 <li><tt>ord</tt>: ordered (no nans)</li>
4566 <li><tt>ueq</tt>: unordered or equal</li>
4567 <li><tt>ugt</tt>: unordered or greater than </li>
4568 <li><tt>uge</tt>: unordered or greater than or equal</li>
4569 <li><tt>ult</tt>: unordered or less than </li>
4570 <li><tt>ule</tt>: unordered or less than or equal</li>
4571 <li><tt>une</tt>: unordered or not equal</li>
4572 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4573 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4574</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4575
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4576<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4577 <i>unordered</i> means that either operand may be a QNAN.</p>
4578
4579<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4580 a <a href="#t_floating">floating point</a> type or
4581 a <a href="#t_vector">vector</a> of floating point type. They must have
4582 identical types.</p>
4583
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4584<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4585<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4586 according to the condition code given as <tt>cond</tt>. If the operands are
4587 vectors, then the vectors are compared element by element. Each comparison
4588 performed always yields an <a href="#t_primitive">i1</a> result, as
4589 follows:</p>
4590
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4591<ol>
4592 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4593
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4594 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4595 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4596
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4597 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4598 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4599
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4600 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4601 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4602
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4603 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4604 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4605
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4606 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4607 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4608
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4609 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4610 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4611
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4612 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4613
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4614 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4615 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4616
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4617 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4618 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4619
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4620 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4622
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4623 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4624 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4625
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4626 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4627 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4628
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4629 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4630 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4631
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4632 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4633
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4634 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4635</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4636
4637<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4638<pre>
4639 &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]4640 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4641 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4642 &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]4643</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4644
4645<p>Note that the code generator does not yet support vector types with
4646 the <tt>fcmp</tt> instruction.</p>
4647
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4648</div>
4649
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4650<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4651<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4652 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4653</div>
4654
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4655<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4656
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4657<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4658<pre>
4659 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4660</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4661
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4662<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4663<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4664 SSA graph representing the function.</p>
4665
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4666<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4667<p>The type of the incoming values is specified with the first type field. After
4668 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4669 one pair for each predecessor basic block of the current block. Only values
4670 of <a href="#t_firstclass">first class</a> type may be used as the value
4671 arguments to the PHI node. Only labels may be used as the label
4672 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4673
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4674<p>There must be no non-phi instructions between the start of a basic block and
4675 the PHI instructions: i.e. PHI instructions must be first in a basic
4676 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4677
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4678<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4679 occur on the edge from the corresponding predecessor block to the current
4680 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4681 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]4682
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4683<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4684<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4685 specified by the pair corresponding to the predecessor basic block that
4686 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4687
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4688<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4689<pre>
4690Loop: ; Infinite loop that counts from 0 on up...
4691 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4692 %nextindvar = add i32 %indvar, 1
4693 br label %Loop
4694</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4695
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4696</div>
4697
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4698<!-- _______________________________________________________________________ -->
4699<div class="doc_subsubsection">
4700 <a name="i_select">'<tt>select</tt>' Instruction</a>
4701</div>
4702
4703<div class="doc_text">
4704
4705<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4706<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4707 &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>
4708
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4709 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4710</pre>
4711
4712<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4713<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4714 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4715
4716
4717<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4718<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4719 values indicating the condition, and two values of the
4720 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4721 vectors and the condition is a scalar, then entire vectors are selected, not
4722 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4723
4724<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4725<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4726 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4727
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4728<p>If the condition is a vector of i1, then the value arguments must be vectors
4729 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4730
4731<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4732<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4733 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4734</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4735
4736<p>Note that the code generator does not yet support conditions
4737 with vector type.</p>
4738
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4739</div>
4740
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4741<!-- _______________________________________________________________________ -->
4742<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4743 <a name="i_call">'<tt>call</tt>' Instruction</a>
4744</div>
4745
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4746<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4747
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4748<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4749<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4750 &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]4751</pre>
4752
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4753<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4754<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4755
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4756<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4757<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4758
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4759<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4760 <li>The optional "tail" marker indicates whether the callee function accesses
4761 any allocas or varargs in the caller. If the "tail" marker is present,
4762 the function call is eligible for tail call optimization. Note that calls
4763 may be marked "tail" even if they do not occur before
4764 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4765
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4766 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4767 convention</a> the call should use. If none is specified, the call
4768 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4769
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4770 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4771 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4772 '<tt>inreg</tt>' attributes are valid here.</li>
4773
4774 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4775 type of the return value. Functions that return no value are marked
4776 <tt><a href="#t_void">void</a></tt>.</li>
4777
4778 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4779 being invoked. The argument types must match the types implied by this
4780 signature. This type can be omitted if the function is not varargs and if
4781 the function type does not return a pointer to a function.</li>
4782
4783 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4784 be invoked. In most cases, this is a direct function invocation, but
4785 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4786 to function value.</li>
4787
4788 <li>'<tt>function args</tt>': argument list whose types match the function
4789 signature argument types. All arguments must be of
4790 <a href="#t_firstclass">first class</a> type. If the function signature
4791 indicates the function accepts a variable number of arguments, the extra
4792 arguments can be specified.</li>
4793
4794 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4795 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4796 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4797</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4798
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4799<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4800<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4801 a specified function, with its incoming arguments bound to the specified
4802 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4803 function, control flow continues with the instruction after the function
4804 call, and the return value of the function is bound to the result
4805 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4806
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4807<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4808<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4809 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4810 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4811 %X = tail call i32 @foo() <i>; yields i32</i>
4812 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4813 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4814
4815 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4816 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4817 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4818 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4819 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4820 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4821</pre>
4822
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4823</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4824
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4825<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4826<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4827 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4828</div>
4829
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4830<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4831
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4832<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4833<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4834 &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]4835</pre>
4836
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4837<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4838<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4839 the "variable argument" area of a function call. It is used to implement the
4840 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4841
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4842<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4843<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4844 argument. It returns a value of the specified argument type and increments
4845 the <tt>va_list</tt> to point to the next argument. The actual type
4846 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4847
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4848<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4849<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4850 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4851 to the next argument. For more information, see the variable argument
4852 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4853
4854<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4855 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4856 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4857
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4858<p><tt>va_arg</tt> is an LLVM instruction instead of
4859 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4860 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4861
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4862<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4863<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4864
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4865<p>Note that the code generator does not yet fully support va_arg on many
4866 targets. Also, it does not currently support va_arg with aggregate types on
4867 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4868
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4869</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4870
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4871<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4872<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4873<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4874
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4875<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4876
4877<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4878 well known names and semantics and are required to follow certain
4879 restrictions. Overall, these intrinsics represent an extension mechanism for
4880 the LLVM language that does not require changing all of the transformations
4881 in LLVM when adding to the language (or the bitcode reader/writer, the
4882 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4883
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4884<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4885 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4886 begin with this prefix. Intrinsic functions must always be external
4887 functions: you cannot define the body of intrinsic functions. Intrinsic
4888 functions may only be used in call or invoke instructions: it is illegal to
4889 take the address of an intrinsic function. Additionally, because intrinsic
4890 functions are part of the LLVM language, it is required if any are added that
4891 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4892
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4893<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4894 family of functions that perform the same operation but on different data
4895 types. Because LLVM can represent over 8 million different integer types,
4896 overloading is used commonly to allow an intrinsic function to operate on any
4897 integer type. One or more of the argument types or the result type can be
4898 overloaded to accept any integer type. Argument types may also be defined as
4899 exactly matching a previous argument's type or the result type. This allows
4900 an intrinsic function which accepts multiple arguments, but needs all of them
4901 to be of the same type, to only be overloaded with respect to a single
4902 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4903
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4904<p>Overloaded intrinsics will have the names of its overloaded argument types
4905 encoded into its function name, each preceded by a period. Only those types
4906 which are overloaded result in a name suffix. Arguments whose type is matched
4907 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4908 can take an integer of any width and returns an integer of exactly the same
4909 integer width. This leads to a family of functions such as
4910 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4911 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4912 suffix is required. Because the argument's type is matched against the return
4913 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4914
4915<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4916 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4917
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4918</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4919
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4920<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4921<div class="doc_subsection">
4922 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4923</div>
4924
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4925<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4927<p>Variable argument support is defined in LLVM with
4928 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
4929 intrinsic functions. These functions are related to the similarly named
4930 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4931
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4932<p>All of these functions operate on arguments that use a target-specific value
4933 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
4934 not define what this type is, so all transformations should be prepared to
4935 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4936
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4937<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4938 instruction and the variable argument handling intrinsic functions are
4939 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4940
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4941<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4942<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4943define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4944 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4945 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4946 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4947 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4948
4949 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4950 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4951
4952 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4953 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4954 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4955 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4956 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4957
4958 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4959 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4960 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4961}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4962
4963declare void @llvm.va_start(i8*)
4964declare void @llvm.va_copy(i8*, i8*)
4965declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4966</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4967</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4968
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4969</div>
4970
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4971<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4972<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4973 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4974</div>
4975
4976
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4977<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4978
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4979<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4980<pre>
4981 declare void %llvm.va_start(i8* &lt;arglist&gt;)
4982</pre>
4983
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4984<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4985<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
4986 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4987
4988<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4989<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]4990
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4991<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4992<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4993 macro available in C. In a target-dependent way, it initializes
4994 the <tt>va_list</tt> element to which the argument points, so that the next
4995 call to <tt>va_arg</tt> will produce the first variable argument passed to
4996 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
4997 need to know the last argument of the function as the compiler can figure
4998 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4999
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5000</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5001
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5002<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5003<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5004 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5005</div>
5006
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5007<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5008
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5009<h5>Syntax:</h5>
5010<pre>
5011 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5012</pre>
5013
5014<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5015<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5016 which has been initialized previously
5017 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5018 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5019
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5020<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5021<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]5022
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5023<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5024<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5025 macro available in C. In a target-dependent way, it destroys
5026 the <tt>va_list</tt> element to which the argument points. Calls
5027 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5028 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5029 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5030
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5031</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5032
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5033<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5034<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5035 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5036</div>
5037
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5038<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5039
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5040<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5041<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5042 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5043</pre>
5044
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5045<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5046<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5047 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5048
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5049<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5050<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5051 The second argument is a pointer to a <tt>va_list</tt> element to copy
5052 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5053
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5054<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5055<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5056 macro available in C. In a target-dependent way, it copies the
5057 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5058 element. This intrinsic is necessary because
5059 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5060 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5061
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5062</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5063
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5064<!-- ======================================================================= -->
5065<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5066 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5067</div>
5068
5069<div class="doc_text">
5070
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5071<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5072Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5073intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5074roots on the stack</a>, as well as garbage collector implementations that
5075require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5076barriers. Front-ends for type-safe garbage collected languages should generate
5077these intrinsics to make use of the LLVM garbage collectors. For more details,
5078see <a href="GarbageCollection.html">Accurate Garbage Collection with
5079LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5080
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5081<p>The garbage collection intrinsics only operate on objects in the generic
5082 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5083
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5084</div>
5085
5086<!-- _______________________________________________________________________ -->
5087<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5088 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5089</div>
5090
5091<div class="doc_text">
5092
5093<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5094<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5095 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5096</pre>
5097
5098<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5099<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5100 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5101
5102<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5103<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5104 root pointer. The second pointer (which must be either a constant or a
5105 global value address) contains the meta-data to be associated with the
5106 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5107
5108<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5109<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5110 location. At compile-time, the code generator generates information to allow
5111 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5112 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5113 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5114
5115</div>
5116
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5117<!-- _______________________________________________________________________ -->
5118<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5119 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5120</div>
5121
5122<div class="doc_text">
5123
5124<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5125<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5126 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5127</pre>
5128
5129<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5130<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5131 locations, allowing garbage collector implementations that require read
5132 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5133
5134<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5135<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5136 allocated from the garbage collector. The first object is a pointer to the
5137 start of the referenced object, if needed by the language runtime (otherwise
5138 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5139
5140<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5141<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5142 instruction, but may be replaced with substantially more complex code by the
5143 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5144 may only be used in a function which <a href="#gc">specifies a GC
5145 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5146
5147</div>
5148
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5149<!-- _______________________________________________________________________ -->
5150<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5151 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5152</div>
5153
5154<div class="doc_text">
5155
5156<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5157<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5158 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5159</pre>
5160
5161<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5162<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5163 locations, allowing garbage collector implementations that require write
5164 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5165
5166<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5167<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5168 object to store it to, and the third is the address of the field of Obj to
5169 store to. If the runtime does not require a pointer to the object, Obj may
5170 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5171
5172<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5173<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5174 instruction, but may be replaced with substantially more complex code by the
5175 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5176 may only be used in a function which <a href="#gc">specifies a GC
5177 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5178
5179</div>
5180
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5181<!-- ======================================================================= -->
5182<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5183 <a name="int_codegen">Code Generator Intrinsics</a>
5184</div>
5185
5186<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5187
5188<p>These intrinsics are provided by LLVM to expose special features that may
5189 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5190
5191</div>
5192
5193<!-- _______________________________________________________________________ -->
5194<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5195 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5196</div>
5197
5198<div class="doc_text">
5199
5200<h5>Syntax:</h5>
5201<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5202 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5203</pre>
5204
5205<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5206<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5207 target-specific value indicating the return address of the current function
5208 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5209
5210<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5211<p>The argument to this intrinsic indicates which function to return the address
5212 for. Zero indicates the calling function, one indicates its caller, etc.
5213 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5214
5215<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5216<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5217 indicating the return address of the specified call frame, or zero if it
5218 cannot be identified. The value returned by this intrinsic is likely to be
5219 incorrect or 0 for arguments other than zero, so it should only be used for
5220 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5221
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5222<p>Note that calling this intrinsic does not prevent function inlining or other
5223 aggressive transformations, so the value returned may not be that of the
5224 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5225
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5226</div>
5227
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5228<!-- _______________________________________________________________________ -->
5229<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5230 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5231</div>
5232
5233<div class="doc_text">
5234
5235<h5>Syntax:</h5>
5236<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5237 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5238</pre>
5239
5240<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5241<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5242 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5243
5244<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5245<p>The argument to this intrinsic indicates which function to return the frame
5246 pointer for. Zero indicates the calling function, one indicates its caller,
5247 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5248
5249<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5250<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5251 indicating the frame address of the specified call frame, or zero if it
5252 cannot be identified. The value returned by this intrinsic is likely to be
5253 incorrect or 0 for arguments other than zero, so it should only be used for
5254 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5255
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256<p>Note that calling this intrinsic does not prevent function inlining or other
5257 aggressive transformations, so the value returned may not be that of the
5258 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5259
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5260</div>
5261
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5262<!-- _______________________________________________________________________ -->
5263<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5264 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5265</div>
5266
5267<div class="doc_text">
5268
5269<h5>Syntax:</h5>
5270<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5271 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5272</pre>
5273
5274<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5275<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5276 of the function stack, for use
5277 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5278 useful for implementing language features like scoped automatic variable
5279 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5280
5281<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5282<p>This intrinsic returns a opaque pointer value that can be passed
5283 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5284 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5285 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5286 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5287 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5288 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5289
5290</div>
5291
5292<!-- _______________________________________________________________________ -->
5293<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5294 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5295</div>
5296
5297<div class="doc_text">
5298
5299<h5>Syntax:</h5>
5300<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5301 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5302</pre>
5303
5304<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5305<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5306 the function stack to the state it was in when the
5307 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5308 executed. This is useful for implementing language features like scoped
5309 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5310
5311<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5312<p>See the description
5313 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5314
5315</div>
5316
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5317<!-- _______________________________________________________________________ -->
5318<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5319 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5320</div>
5321
5322<div class="doc_text">
5323
5324<h5>Syntax:</h5>
5325<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5326 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]5327</pre>
5328
5329<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5330<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5331 insert a prefetch instruction if supported; otherwise, it is a noop.
5332 Prefetches have no effect on the behavior of the program but can change its
5333 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5334
5335<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5336<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5337 specifier determining if the fetch should be for a read (0) or write (1),
5338 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5339 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5340 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5341
5342<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5343<p>This intrinsic does not modify the behavior of the program. In particular,
5344 prefetches cannot trap and do not produce a value. On targets that support
5345 this intrinsic, the prefetch can provide hints to the processor cache for
5346 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5347
5348</div>
5349
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5350<!-- _______________________________________________________________________ -->
5351<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5352 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5353</div>
5354
5355<div class="doc_text">
5356
5357<h5>Syntax:</h5>
5358<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5359 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5360</pre>
5361
5362<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5363<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5364 Counter (PC) in a region of code to simulators and other tools. The method
5365 is target specific, but it is expected that the marker will use exported
5366 symbols to transmit the PC of the marker. The marker makes no guarantees
5367 that it will remain with any specific instruction after optimizations. It is
5368 possible that the presence of a marker will inhibit optimizations. The
5369 intended use is to be inserted after optimizations to allow correlations of
5370 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5371
5372<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5373<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5374
5375<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5376<p>This intrinsic does not modify the behavior of the program. Backends that do
5377 not support this intrinisic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5378
5379</div>
5380
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5381<!-- _______________________________________________________________________ -->
5382<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5383 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5384</div>
5385
5386<div class="doc_text">
5387
5388<h5>Syntax:</h5>
5389<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5390 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5391</pre>
5392
5393<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5394<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5395 counter register (or similar low latency, high accuracy clocks) on those
5396 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5397 should map to RPCC. As the backing counters overflow quickly (on the order
5398 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5399
5400<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5401<p>When directly supported, reading the cycle counter should not modify any
5402 memory. Implementations are allowed to either return a application specific
5403 value or a system wide value. On backends without support, this is lowered
5404 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5405
5406</div>
5407
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5408<!-- ======================================================================= -->
5409<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5410 <a name="int_libc">Standard C Library Intrinsics</a>
5411</div>
5412
5413<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5414
5415<p>LLVM provides intrinsics for a few important standard C library functions.
5416 These intrinsics allow source-language front-ends to pass information about
5417 the alignment of the pointer arguments to the code generator, providing
5418 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5419
5420</div>
5421
5422<!-- _______________________________________________________________________ -->
5423<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5424 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5425</div>
5426
5427<div class="doc_text">
5428
5429<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5430<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5431 integer bit width. Not all targets support all bit widths however.</p>
5432
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5433<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5434 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5435 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5436 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5437 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5438 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5439 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5440 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5441 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5442</pre>
5443
5444<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5445<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5446 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5447
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5448<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5449 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5450
5451<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5452<p>The first argument is a pointer to the destination, the second is a pointer
5453 to the source. The third argument is an integer argument specifying the
5454 number of bytes to copy, and the fourth argument is the alignment of the
5455 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5456
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5457<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5458 then the caller guarantees that both the source and destination pointers are
5459 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5460
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5461<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5462<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5463 source location to the destination location, which are not allowed to
5464 overlap. It copies "len" bytes of memory over. If the argument is known to
5465 be aligned to some boundary, this can be specified as the fourth argument,
5466 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5467
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5468</div>
5469
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5470<!-- _______________________________________________________________________ -->
5471<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5472 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5473</div>
5474
5475<div class="doc_text">
5476
5477<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5478<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5479 width. Not all targets support all bit widths however.</p>
5480
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5481<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5482 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5483 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5484 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5485 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5486 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5487 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5488 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5489 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5490</pre>
5491
5492<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5493<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5494 source location to the destination location. It is similar to the
5495 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5496 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5497
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5498<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5499 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5500
5501<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5502<p>The first argument is a pointer to the destination, the second is a pointer
5503 to the source. The third argument is an integer argument specifying the
5504 number of bytes to copy, and the fourth argument is the alignment of the
5505 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5506
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5507<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5508 then the caller guarantees that the source and destination pointers are
5509 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5510
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5511<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5512<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5513 source location to the destination location, which may overlap. It copies
5514 "len" bytes of memory over. If the argument is known to be aligned to some
5515 boundary, this can be specified as the fourth argument, otherwise it should
5516 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5517
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5518</div>
5519
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5520<!-- _______________________________________________________________________ -->
5521<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5522 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5523</div>
5524
5525<div class="doc_text">
5526
5527<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5528<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5529 width. Not all targets support all bit widths however.</p>
5530
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5531<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5532 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5533 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5534 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5535 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5536 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5537 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5538 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5539 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5540</pre>
5541
5542<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5543<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5544 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5545
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5546<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5547 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5548
5549<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5550<p>The first argument is a pointer to the destination to fill, the second is the
5551 byte value to fill it with, the third argument is an integer argument
5552 specifying the number of bytes to fill, and the fourth argument is the known
5553 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5554
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5555<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5556 then the caller guarantees that the destination pointer is aligned to that
5557 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5558
5559<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5560<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5561 at the destination location. If the argument is known to be aligned to some
5562 boundary, this can be specified as the fourth argument, otherwise it should
5563 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5564
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5565</div>
5566
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5567<!-- _______________________________________________________________________ -->
5568<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5569 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5570</div>
5571
5572<div class="doc_text">
5573
5574<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5575<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5576 floating point or vector of floating point type. Not all targets support all
5577 types however.</p>
5578
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5579<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5580 declare float @llvm.sqrt.f32(float %Val)
5581 declare double @llvm.sqrt.f64(double %Val)
5582 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5583 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5584 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5585</pre>
5586
5587<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5588<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5589 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5590 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5591 behavior for negative numbers other than -0.0 (which allows for better
5592 optimization, because there is no need to worry about errno being
5593 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5594
5595<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5596<p>The argument and return value are floating point numbers of the same
5597 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5598
5599<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5600<p>This function returns the sqrt of the specified operand if it is a
5601 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5602
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5603</div>
5604
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5605<!-- _______________________________________________________________________ -->
5606<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5607 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5608</div>
5609
5610<div class="doc_text">
5611
5612<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5614 floating point or vector of floating point type. Not all targets support all
5615 types however.</p>
5616
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5617<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5618 declare float @llvm.powi.f32(float %Val, i32 %power)
5619 declare double @llvm.powi.f64(double %Val, i32 %power)
5620 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5621 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5622 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5623</pre>
5624
5625<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5626<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5627 specified (positive or negative) power. The order of evaluation of
5628 multiplications is not defined. When a vector of floating point type is
5629 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5630
5631<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5632<p>The second argument is an integer power, and the first is a value to raise to
5633 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5634
5635<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5636<p>This function returns the first value raised to the second power with an
5637 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5638
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5639</div>
5640
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5641<!-- _______________________________________________________________________ -->
5642<div class="doc_subsubsection">
5643 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5644</div>
5645
5646<div class="doc_text">
5647
5648<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5649<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5650 floating point or vector of floating point type. Not all targets support all
5651 types however.</p>
5652
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5653<pre>
5654 declare float @llvm.sin.f32(float %Val)
5655 declare double @llvm.sin.f64(double %Val)
5656 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5657 declare fp128 @llvm.sin.f128(fp128 %Val)
5658 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5659</pre>
5660
5661<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5662<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5663
5664<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5665<p>The argument and return value are floating point numbers of the same
5666 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5667
5668<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5669<p>This function returns the sine of the specified operand, returning the same
5670 values as the libm <tt>sin</tt> functions would, and handles error conditions
5671 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5672
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5673</div>
5674
5675<!-- _______________________________________________________________________ -->
5676<div class="doc_subsubsection">
5677 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5678</div>
5679
5680<div class="doc_text">
5681
5682<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5683<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5684 floating point or vector of floating point type. Not all targets support all
5685 types however.</p>
5686
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5687<pre>
5688 declare float @llvm.cos.f32(float %Val)
5689 declare double @llvm.cos.f64(double %Val)
5690 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5691 declare fp128 @llvm.cos.f128(fp128 %Val)
5692 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5693</pre>
5694
5695<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5696<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5697
5698<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5699<p>The argument and return value are floating point numbers of the same
5700 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5701
5702<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5703<p>This function returns the cosine of the specified operand, returning the same
5704 values as the libm <tt>cos</tt> functions would, and handles error conditions
5705 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5706
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5707</div>
5708
5709<!-- _______________________________________________________________________ -->
5710<div class="doc_subsubsection">
5711 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5712</div>
5713
5714<div class="doc_text">
5715
5716<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5717<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5718 floating point or vector of floating point type. Not all targets support all
5719 types however.</p>
5720
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5721<pre>
5722 declare float @llvm.pow.f32(float %Val, float %Power)
5723 declare double @llvm.pow.f64(double %Val, double %Power)
5724 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5725 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5726 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5727</pre>
5728
5729<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5730<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5731 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5732
5733<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5734<p>The second argument is a floating point power, and the first is a value to
5735 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5736
5737<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5738<p>This function returns the first value raised to the second power, returning
5739 the same values as the libm <tt>pow</tt> functions would, and handles error
5740 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5741
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5742</div>
5743
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5744<!-- ======================================================================= -->
5745<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5746 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5747</div>
5748
5749<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5750
5751<p>LLVM provides intrinsics for a few important bit manipulation operations.
5752 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5753
5754</div>
5755
5756<!-- _______________________________________________________________________ -->
5757<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5758 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5759</div>
5760
5761<div class="doc_text">
5762
5763<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5764<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5765 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5766
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5767<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5768 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5769 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5770 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5771</pre>
5772
5773<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5774<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5775 values with an even number of bytes (positive multiple of 16 bits). These
5776 are useful for performing operations on data that is not in the target's
5777 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5778
5779<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5780<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5781 and low byte of the input i16 swapped. Similarly,
5782 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5783 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5784 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5785 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5786 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5787 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5788
5789</div>
5790
5791<!-- _______________________________________________________________________ -->
5792<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5793 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5794</div>
5795
5796<div class="doc_text">
5797
5798<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5799<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5800 width. Not all targets support all bit widths however.</p>
5801
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5802<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5803 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5804 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5805 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5806 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5807 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5808</pre>
5809
5810<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5811<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5812 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5813
5814<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5815<p>The only argument is the value to be counted. The argument may be of any
5816 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5817
5818<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5819<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5820
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5821</div>
5822
5823<!-- _______________________________________________________________________ -->
5824<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5825 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5826</div>
5827
5828<div class="doc_text">
5829
5830<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5831<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5832 integer bit width. Not all targets support all bit widths however.</p>
5833
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5834<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5835 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5836 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5837 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5838 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5839 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5840</pre>
5841
5842<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5843<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5844 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5845
5846<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5847<p>The only argument is the value to be counted. The argument may be of any
5848 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5849
5850<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5851<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5852 zeros in a variable. If the src == 0 then the result is the size in bits of
5853 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5854
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5855</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5856
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5857<!-- _______________________________________________________________________ -->
5858<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5859 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5860</div>
5861
5862<div class="doc_text">
5863
5864<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5865<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5866 integer bit width. Not all targets support all bit widths however.</p>
5867
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5868<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5869 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5870 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5871 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5872 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5873 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5874</pre>
5875
5876<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5877<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5878 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5879
5880<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5881<p>The only argument is the value to be counted. The argument may be of any
5882 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5883
5884<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5885<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5886 zeros in a variable. If the src == 0 then the result is the size in bits of
5887 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5888
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5889</div>
5890
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5891<!-- ======================================================================= -->
5892<div class="doc_subsection">
5893 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5894</div>
5895
5896<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5897
5898<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5899
5900</div>
5901
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5902<!-- _______________________________________________________________________ -->
5903<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5904 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5905</div>
5906
5907<div class="doc_text">
5908
5909<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5910<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5911 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5912
5913<pre>
5914 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5915 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5916 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5917</pre>
5918
5919<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5920<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5921 a signed addition of the two arguments, and indicate whether an overflow
5922 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5923
5924<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5925<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5926 be of integer types of any bit width, but they must have the same bit
5927 width. The second element of the result structure must be of
5928 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
5929 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5930
5931<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5932<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5933 a signed addition of the two variables. They return a structure &mdash; the
5934 first element of which is the signed summation, and the second element of
5935 which is a bit specifying if the signed summation resulted in an
5936 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5937
5938<h5>Examples:</h5>
5939<pre>
5940 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5941 %sum = extractvalue {i32, i1} %res, 0
5942 %obit = extractvalue {i32, i1} %res, 1
5943 br i1 %obit, label %overflow, label %normal
5944</pre>
5945
5946</div>
5947
5948<!-- _______________________________________________________________________ -->
5949<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5950 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5951</div>
5952
5953<div class="doc_text">
5954
5955<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5956<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5957 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5958
5959<pre>
5960 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
5961 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
5962 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
5963</pre>
5964
5965<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5966<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5967 an unsigned addition of the two arguments, and indicate whether a carry
5968 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5969
5970<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5971<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5972 be of integer types of any bit width, but they must have the same bit
5973 width. The second element of the result structure must be of
5974 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
5975 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5976
5977<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5978<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5979 an unsigned addition of the two arguments. They return a structure &mdash;
5980 the first element of which is the sum, and the second element of which is a
5981 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5982
5983<h5>Examples:</h5>
5984<pre>
5985 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
5986 %sum = extractvalue {i32, i1} %res, 0
5987 %obit = extractvalue {i32, i1} %res, 1
5988 br i1 %obit, label %carry, label %normal
5989</pre>
5990
5991</div>
5992
5993<!-- _______________________________________________________________________ -->
5994<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5995 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5996</div>
5997
5998<div class="doc_text">
5999
6000<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6001<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6002 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6003
6004<pre>
6005 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6006 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6007 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6008</pre>
6009
6010<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6011<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6012 a signed subtraction of the two arguments, and indicate whether an overflow
6013 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6014
6015<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6016<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6017 be of integer types of any bit width, but they must have the same bit
6018 width. The second element of the result structure must be of
6019 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6020 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6021
6022<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6023<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6024 a signed subtraction of the two arguments. They return a structure &mdash;
6025 the first element of which is the subtraction, and the second element of
6026 which is a bit specifying if the signed subtraction resulted in an
6027 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6028
6029<h5>Examples:</h5>
6030<pre>
6031 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6032 %sum = extractvalue {i32, i1} %res, 0
6033 %obit = extractvalue {i32, i1} %res, 1
6034 br i1 %obit, label %overflow, label %normal
6035</pre>
6036
6037</div>
6038
6039<!-- _______________________________________________________________________ -->
6040<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6041 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6042</div>
6043
6044<div class="doc_text">
6045
6046<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6047<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6048 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6049
6050<pre>
6051 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6052 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6053 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6054</pre>
6055
6056<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6057<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6058 an unsigned subtraction of the two arguments, and indicate whether an
6059 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6060
6061<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6062<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6063 be of integer types of any bit width, but they must have the same bit
6064 width. The second element of the result structure must be of
6065 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6066 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6067
6068<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6069<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6070 an unsigned subtraction of the two arguments. They return a structure &mdash;
6071 the first element of which is the subtraction, and the second element of
6072 which is a bit specifying if the unsigned subtraction resulted in an
6073 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6074
6075<h5>Examples:</h5>
6076<pre>
6077 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6078 %sum = extractvalue {i32, i1} %res, 0
6079 %obit = extractvalue {i32, i1} %res, 1
6080 br i1 %obit, label %overflow, label %normal
6081</pre>
6082
6083</div>
6084
6085<!-- _______________________________________________________________________ -->
6086<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6087 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6088</div>
6089
6090<div class="doc_text">
6091
6092<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6093<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6094 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6095
6096<pre>
6097 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6098 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6099 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6100</pre>
6101
6102<h5>Overview:</h5>
6103
6104<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6105 a signed multiplication of the two arguments, and indicate whether an
6106 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6107
6108<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6109<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6110 be of integer types of any bit width, but they must have the same bit
6111 width. The second element of the result structure must be of
6112 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6113 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6114
6115<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6116<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6117 a signed multiplication of the two arguments. They return a structure &mdash;
6118 the first element of which is the multiplication, and the second element of
6119 which is a bit specifying if the signed multiplication resulted in an
6120 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6121
6122<h5>Examples:</h5>
6123<pre>
6124 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6125 %sum = extractvalue {i32, i1} %res, 0
6126 %obit = extractvalue {i32, i1} %res, 1
6127 br i1 %obit, label %overflow, label %normal
6128</pre>
6129
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6130</div>
6131
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6132<!-- _______________________________________________________________________ -->
6133<div class="doc_subsubsection">
6134 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6135</div>
6136
6137<div class="doc_text">
6138
6139<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6140<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6141 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6142
6143<pre>
6144 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6145 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6146 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6147</pre>
6148
6149<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6150<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6151 a unsigned multiplication of the two arguments, and indicate whether an
6152 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6153
6154<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6155<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6156 be of integer types of any bit width, but they must have the same bit
6157 width. The second element of the result structure must be of
6158 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6159 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6160
6161<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6162<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6163 an unsigned multiplication of the two arguments. They return a structure
6164 &mdash; the first element of which is the multiplication, and the second
6165 element of which is a bit specifying if the unsigned multiplication resulted
6166 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6167
6168<h5>Examples:</h5>
6169<pre>
6170 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6171 %sum = extractvalue {i32, i1} %res, 0
6172 %obit = extractvalue {i32, i1} %res, 1
6173 br i1 %obit, label %overflow, label %normal
6174</pre>
6175
6176</div>
6177
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6178<!-- ======================================================================= -->
6179<div class="doc_subsection">
6180 <a name="int_debugger">Debugger Intrinsics</a>
6181</div>
6182
6183<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6184
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6185<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6186 prefix), are described in
6187 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6188 Level Debugging</a> document.</p>
6189
6190</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6191
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6192<!-- ======================================================================= -->
6193<div class="doc_subsection">
6194 <a name="int_eh">Exception Handling Intrinsics</a>
6195</div>
6196
6197<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6198
6199<p>The LLVM exception handling intrinsics (which all start with
6200 <tt>llvm.eh.</tt> prefix), are described in
6201 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6202 Handling</a> document.</p>
6203
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6204</div>
6205
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6206<!-- ======================================================================= -->
6207<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6208 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6209</div>
6210
6211<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6212
6213<p>This intrinsic makes it possible to excise one parameter, marked with
6214 the <tt>nest</tt> attribute, from a function. The result is a callable
6215 function pointer lacking the nest parameter - the caller does not need to
6216 provide a value for it. Instead, the value to use is stored in advance in a
6217 "trampoline", a block of memory usually allocated on the stack, which also
6218 contains code to splice the nest value into the argument list. This is used
6219 to implement the GCC nested function address extension.</p>
6220
6221<p>For example, if the function is
6222 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6223 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6224 follows:</p>
6225
6226<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6227<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6228 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6229 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6230 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6231 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6232</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6233</div>
6234
6235<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6236 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6237
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6238</div>
6239
6240<!-- _______________________________________________________________________ -->
6241<div class="doc_subsubsection">
6242 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6243</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6244
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6245<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6246
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6247<h5>Syntax:</h5>
6248<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6249 declare 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]6250</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6251
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6252<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6253<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6254 function pointer suitable for executing it.</p>
6255
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6256<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6257<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6258 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6259 sufficiently aligned block of memory; this memory is written to by the
6260 intrinsic. Note that the size and the alignment are target-specific - LLVM
6261 currently provides no portable way of determining them, so a front-end that
6262 generates this intrinsic needs to have some target-specific knowledge.
6263 The <tt>func</tt> argument must hold a function bitcast to
6264 an <tt>i8*</tt>.</p>
6265
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6266<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6267<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6268 dependent code, turning it into a function. A pointer to this function is
6269 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6270 function pointer type</a> before being called. The new function's signature
6271 is the same as that of <tt>func</tt> with any arguments marked with
6272 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6273 is allowed, and it must be of pointer type. Calling the new function is
6274 equivalent to calling <tt>func</tt> with the same argument list, but
6275 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6276 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6277 by <tt>tramp</tt> is modified, then the effect of any later call to the
6278 returned function pointer is undefined.</p>
6279
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6280</div>
6281
6282<!-- ======================================================================= -->
6283<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6284 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6285</div>
6286
6287<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6288
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6289<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6290 hardware constructs for atomic operations and memory synchronization. This
6291 provides an interface to the hardware, not an interface to the programmer. It
6292 is aimed at a low enough level to allow any programming models or APIs
6293 (Application Programming Interfaces) which need atomic behaviors to map
6294 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6295 hardware provides a "universal IR" for source languages, it also provides a
6296 starting point for developing a "universal" atomic operation and
6297 synchronization IR.</p>
6298
6299<p>These do <em>not</em> form an API such as high-level threading libraries,
6300 software transaction memory systems, atomic primitives, and intrinsic
6301 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6302 application libraries. The hardware interface provided by LLVM should allow
6303 a clean implementation of all of these APIs and parallel programming models.
6304 No one model or paradigm should be selected above others unless the hardware
6305 itself ubiquitously does so.</p>
6306
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6307</div>
6308
6309<!-- _______________________________________________________________________ -->
6310<div class="doc_subsubsection">
6311 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6312</div>
6313<div class="doc_text">
6314<h5>Syntax:</h5>
6315<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6316 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6317</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6318
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6319<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6320<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6321 specific pairs of memory access types.</p>
6322
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6323<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6324<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6325 The first four arguments enables a specific barrier as listed below. The
6326 fith argument specifies that the barrier applies to io or device or uncached
6327 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6328
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6329<ul>
6330 <li><tt>ll</tt>: load-load barrier</li>
6331 <li><tt>ls</tt>: load-store barrier</li>
6332 <li><tt>sl</tt>: store-load barrier</li>
6333 <li><tt>ss</tt>: store-store barrier</li>
6334 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6335</ul>
6336
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6337<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6338<p>This intrinsic causes the system to enforce some ordering constraints upon
6339 the loads and stores of the program. This barrier does not
6340 indicate <em>when</em> any events will occur, it only enforces
6341 an <em>order</em> in which they occur. For any of the specified pairs of load
6342 and store operations (f.ex. load-load, or store-load), all of the first
6343 operations preceding the barrier will complete before any of the second
6344 operations succeeding the barrier begin. Specifically the semantics for each
6345 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6346
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6347<ul>
6348 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6349 after the barrier begins.</li>
6350 <li><tt>ls</tt>: All loads before the barrier must complete before any
6351 store after the barrier begins.</li>
6352 <li><tt>ss</tt>: All stores before the barrier must complete before any
6353 store after the barrier begins.</li>
6354 <li><tt>sl</tt>: All stores before the barrier must complete before any
6355 load after the barrier begins.</li>
6356</ul>
6357
6358<p>These semantics are applied with a logical "and" behavior when more than one
6359 is enabled in a single memory barrier intrinsic.</p>
6360
6361<p>Backends may implement stronger barriers than those requested when they do
6362 not support as fine grained a barrier as requested. Some architectures do
6363 not need all types of barriers and on such architectures, these become
6364 noops.</p>
6365
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6366<h5>Example:</h5>
6367<pre>
6368%ptr = malloc i32
6369 store i32 4, %ptr
6370
6371%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6372 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6373 <i>; guarantee the above finishes</i>
6374 store i32 8, %ptr <i>; before this begins</i>
6375</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6376
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6377</div>
6378
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6379<!-- _______________________________________________________________________ -->
6380<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6381 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6382</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6383
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6384<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6385
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6386<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6387<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6388 any integer bit width and for different address spaces. Not all targets
6389 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6390
6391<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6392 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6393 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6394 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6395 declare 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]6396</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6397
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6398<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6399<p>This loads a value in memory and compares it to a given value. If they are
6400 equal, it stores a new value into the memory.</p>
6401
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6402<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6403<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6404 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6405 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6406 this integer type. While any bit width integer may be used, targets may only
6407 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6408
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6409<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6410<p>This entire intrinsic must be executed atomically. It first loads the value
6411 in memory pointed to by <tt>ptr</tt> and compares it with the
6412 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6413 memory. The loaded value is yielded in all cases. This provides the
6414 equivalent of an atomic compare-and-swap operation within the SSA
6415 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6416
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6417<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6418<pre>
6419%ptr = malloc i32
6420 store i32 4, %ptr
6421
6422%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6423%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6424 <i>; yields {i32}:result1 = 4</i>
6425%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6426%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6427
6428%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6429%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6430 <i>; yields {i32}:result2 = 8</i>
6431%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6432
6433%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6434</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6435
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6436</div>
6437
6438<!-- _______________________________________________________________________ -->
6439<div class="doc_subsubsection">
6440 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6441</div>
6442<div class="doc_text">
6443<h5>Syntax:</h5>
6444
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6445<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6446 integer bit width. Not all targets support all bit widths however.</p>
6447
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6448<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6449 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6450 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6451 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6452 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6453</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6454
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6455<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6456<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6457 the value from memory. It then stores the value in <tt>val</tt> in the memory
6458 at <tt>ptr</tt>.</p>
6459
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6460<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6461<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6462 the <tt>val</tt> argument and the result must be integers of the same bit
6463 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6464 integer type. The targets may only lower integer representations they
6465 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6466
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6467<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6468<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6469 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6470 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6471
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6472<h5>Examples:</h5>
6473<pre>
6474%ptr = malloc i32
6475 store i32 4, %ptr
6476
6477%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6478%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6479 <i>; yields {i32}:result1 = 4</i>
6480%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6481%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6482
6483%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6484%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6485 <i>; yields {i32}:result2 = 8</i>
6486
6487%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6488%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6489</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6490
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6491</div>
6492
6493<!-- _______________________________________________________________________ -->
6494<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6495 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6496
6497</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6498
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6499<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6500
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6501<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6502<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6503 any integer bit width. Not all targets support all bit widths however.</p>
6504
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6505<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6506 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6507 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6508 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6509 declare 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]6510</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6511
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6512<h5>Overview:</h5>
6513<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6514 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6515
6516<h5>Arguments:</h5>
6517<p>The intrinsic takes two arguments, the first a pointer to an integer value
6518 and the second an integer value. The result is also an integer value. These
6519 integer types can have any bit width, but they must all have the same bit
6520 width. The targets may only lower integer representations they support.</p>
6521
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6522<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6523<p>This intrinsic does a series of operations atomically. It first loads the
6524 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6525 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6526
6527<h5>Examples:</h5>
6528<pre>
6529%ptr = malloc i32
6530 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6531%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6532 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6533%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6534 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6535%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6536 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6537%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6538</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6539
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6540</div>
6541
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6542<!-- _______________________________________________________________________ -->
6543<div class="doc_subsubsection">
6544 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6545
6546</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6547
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6548<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6549
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6550<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6551<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6552 any integer bit width and for different address spaces. Not all targets
6553 support all bit widths however.</p>
6554
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6555<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6556 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6557 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6558 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6559 declare 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]6560</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6561
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6562<h5>Overview:</h5>
6563<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6564 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6565
6566<h5>Arguments:</h5>
6567<p>The intrinsic takes two arguments, the first a pointer to an integer value
6568 and the second an integer value. The result is also an integer value. These
6569 integer types can have any bit width, but they must all have the same bit
6570 width. The targets may only lower integer representations they support.</p>
6571
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6572<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6573<p>This intrinsic does a series of operations atomically. It first loads the
6574 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6575 result to <tt>ptr</tt>. It yields the original value stored
6576 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6577
6578<h5>Examples:</h5>
6579<pre>
6580%ptr = malloc i32
6581 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6582%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6583 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6584%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6585 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6586%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6587 <i>; yields {i32}:result3 = 2</i>
6588%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6589</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6590
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6591</div>
6592
6593<!-- _______________________________________________________________________ -->
6594<div class="doc_subsubsection">
6595 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6596 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6597 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6598 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6599</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6600
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6601<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6602
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6603<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6604<p>These are overloaded intrinsics. You can
6605 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6606 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6607 bit width and for different address spaces. Not all targets support all bit
6608 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6609
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6610<pre>
6611 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6612 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6613 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6614 declare 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]6615</pre>
6616
6617<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6618 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6619 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6620 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6621 declare 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]6622</pre>
6623
6624<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6625 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6626 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6627 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6628 declare 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]6629</pre>
6630
6631<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6632 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6633 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6634 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6635 declare 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]6636</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6637
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6638<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6639<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6640 the value stored in memory at <tt>ptr</tt>. It yields the original value
6641 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6642
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6643<h5>Arguments:</h5>
6644<p>These intrinsics take two arguments, the first a pointer to an integer value
6645 and the second an integer value. The result is also an integer value. These
6646 integer types can have any bit width, but they must all have the same bit
6647 width. The targets may only lower integer representations they support.</p>
6648
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6649<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6650<p>These intrinsics does a series of operations atomically. They first load the
6651 value stored at <tt>ptr</tt>. They then do the bitwise
6652 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6653 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6654
6655<h5>Examples:</h5>
6656<pre>
6657%ptr = malloc i32
6658 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6659%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6660 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6661%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6662 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6663%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6664 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6665%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6666 <i>; yields {i32}:result3 = FF</i>
6667%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6668</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6669
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6670</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6671
6672<!-- _______________________________________________________________________ -->
6673<div class="doc_subsubsection">
6674 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6675 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6676 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6677 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6678</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6679
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6680<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6681
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6682<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6683<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6684 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6685 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6686 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6687
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6688<pre>
6689 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6690 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6691 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6692 declare 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]6693</pre>
6694
6695<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6696 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6697 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6698 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6699 declare 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]6700</pre>
6701
6702<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6703 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6704 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6705 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6706 declare 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]6707</pre>
6708
6709<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6710 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6711 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6712 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6713 declare 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]6714</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6715
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6716<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6717<p>These intrinsics takes the signed or unsigned minimum or maximum of
6718 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6719 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6720
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6721<h5>Arguments:</h5>
6722<p>These intrinsics take two arguments, the first a pointer to an integer value
6723 and the second an integer value. The result is also an integer value. These
6724 integer types can have any bit width, but they must all have the same bit
6725 width. The targets may only lower integer representations they support.</p>
6726
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6727<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6728<p>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
6730 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6731 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6732
6733<h5>Examples:</h5>
6734<pre>
6735%ptr = malloc i32
6736 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6737%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6738 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6739%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6740 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6741%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6742 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6743%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6744 <i>; yields {i32}:result3 = 8</i>
6745%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6746</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6747
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]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">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6756
6757<p>This class of intrinsics is designed to be generic and has no specific
6758 purpose.</p>
6759
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6760</div>
6761
6762<!-- _______________________________________________________________________ -->
6763<div class="doc_subsubsection">
6764 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6765</div>
6766
6767<div class="doc_text">
6768
6769<h5>Syntax:</h5>
6770<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6771 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]6772</pre>
6773
6774<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6775<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6776
6777<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6778<p>The first argument is a pointer to a value, the second is a pointer to a
6779 global string, the third is a pointer to a global string which is the source
6780 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6781
6782<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6783<p>This intrinsic allows annotation of local variables with arbitrary strings.
6784 This can be useful for special purpose optimizations that want to look for
6785 these annotations. These have no other defined use, they are ignored by code
6786 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6787
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6788</div>
6789
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6790<!-- _______________________________________________________________________ -->
6791<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6792 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6793</div>
6794
6795<div class="doc_text">
6796
6797<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6798<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6799 any integer bit width.</p>
6800
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6801<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6802 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6803 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6804 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6805 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6806 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]6807</pre>
6808
6809<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6810<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6811
6812<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6813<p>The first argument is an integer value (result of some expression), the
6814 second is a pointer to a global string, the third is a pointer to a global
6815 string which is the source file name, and the last argument is the line
6816 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6817
6818<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6819<p>This intrinsic allows annotations to be put on arbitrary expressions with
6820 arbitrary strings. This can be useful for special purpose optimizations that
6821 want to look for these annotations. These have no other defined use, they
6822 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6823
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6824</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6825
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6826<!-- _______________________________________________________________________ -->
6827<div class="doc_subsubsection">
6828 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6829</div>
6830
6831<div class="doc_text">
6832
6833<h5>Syntax:</h5>
6834<pre>
6835 declare void @llvm.trap()
6836</pre>
6837
6838<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6839<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6840
6841<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6842<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6843
6844<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6845<p>This intrinsics is lowered to the target dependent trap instruction. If the
6846 target does not have a trap instruction, this intrinsic will be lowered to
6847 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6848
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6849</div>
6850
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6851<!-- _______________________________________________________________________ -->
6852<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6853 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6854</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6855
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6856<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6857
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6858<h5>Syntax:</h5>
6859<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6860 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6861</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6862
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6863<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6864<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6865 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6866 ensure that it is placed on the stack before local variables.</p>
6867
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6868<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6869<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6870 arguments. The first argument is the value loaded from the stack
6871 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6872 that has enough space to hold the value of the guard.</p>
6873
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6874<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6875<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6876 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6877 stack. This is to ensure that if a local variable on the stack is
6878 overwritten, it will destroy the value of the guard. When the function exits,
6879 the guard on the stack is checked against the original guard. If they're
6880 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6881 function.</p>
6882
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6883</div>
6884
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6885<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6886<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6887<address>
6888 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6889 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6890 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6891 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6892
6893 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6894 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6895 Last modified: $Date$
6896</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6897
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6898</body>
6899</html>