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gerrit-public.fairphone.software / toolchain / llvm-project / 2de532c1327767f9e8ae036f1bc0a3cbae11fe65 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 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 Lattner6af02f32004-12-09 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 Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 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 Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]52 </ol>
53 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]58 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]59 <li><a href="#t_floating">Floating Point Types</a></li>
60 <li><a href="#t_void">Void Type</a></li>
61 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]62 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]63 </ol>
64 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]65 <li><a href="#t_derived">Derived Types</a>
66 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]67 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]73 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]74 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]75 </ol>
76 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]80 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]81 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
86 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]87 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]88 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]89 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]90 <li><a href="#othervalues">Other Values</a>
91 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]93 </ol>
94 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]95 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
96 <ol>
97 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]98 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
99 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]100 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
101 Global Variable</a></li>
102 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
103 Global Variable</a></li>
104 </ol>
105 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]106 <li><a href="#instref">Instruction Reference</a>
107 <ol>
108 <li><a href="#terminators">Terminator Instructions</a>
109 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]110 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
111 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]112 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
113 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]114 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]115 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]116 </ol>
117 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]118 <li><a href="#binaryops">Binary Operations</a>
119 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]121 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]126 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
127 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
128 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]129 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
130 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
131 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 </ol>
133 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
135 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]136 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
137 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
138 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]139 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]141 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]144 <li><a href="#vectorops">Vector Operations</a>
145 <ol>
146 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
147 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
148 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]149 </ol>
150 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]151 <li><a href="#aggregateops">Aggregate Operations</a>
152 <ol>
153 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
154 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
155 </ol>
156 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]157 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]158 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]159 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
160 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]167 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]181 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]191 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]192 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]193 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]194 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]195 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]196 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 </ol>
203 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]232 </ol>
233 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]235 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]249 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]250 </ol>
251 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]276 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]277 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]278 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]279 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]280 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]281 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]282 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]283 '<tt>llvm.trap</tt>' Intrinsic</a></li>
284 <li><a href="#int_stackprotector">
285 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]286 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]287 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]288 </ol>
289 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]290</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]291
292<div class="doc_author">
293 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
294 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]297<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_section"> <a name="abstract">Abstract </a></div>
299<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]302
303<p>This document is a reference manual for the LLVM assembly language. LLVM is
304 a Static Single Assignment (SSA) based representation that provides type
305 safety, low-level operations, flexibility, and the capability of representing
306 'all' high-level languages cleanly. It is the common code representation
307 used throughout all phases of the LLVM compilation strategy.</p>
308
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]309</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]311<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]312<div class="doc_section"> <a name="introduction">Introduction</a> </div>
313<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]314
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]315<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]316
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]317<p>The LLVM code representation is designed to be used in three different forms:
318 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
319 for fast loading by a Just-In-Time compiler), and as a human readable
320 assembly language representation. This allows LLVM to provide a powerful
321 intermediate representation for efficient compiler transformations and
322 analysis, while providing a natural means to debug and visualize the
323 transformations. The three different forms of LLVM are all equivalent. This
324 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]326<p>The LLVM representation aims to be light-weight and low-level while being
327 expressive, typed, and extensible at the same time. It aims to be a
328 "universal IR" of sorts, by being at a low enough level that high-level ideas
329 may be cleanly mapped to it (similar to how microprocessors are "universal
330 IR's", allowing many source languages to be mapped to them). By providing
331 type information, LLVM can be used as the target of optimizations: for
332 example, through pointer analysis, it can be proven that a C automatic
333 variable is never accessed outside of the current function... allowing it to
334 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]335
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]338<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]339<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]340
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]341<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]343<p>It is important to note that this document describes 'well formed' LLVM
344 assembly language. There is a difference between what the parser accepts and
345 what is considered 'well formed'. For example, the following instruction is
346 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]348<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]349<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]350%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]351</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]352</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]354<p>...because the definition of <tt>%x</tt> does not dominate all of its
355 uses. The LLVM infrastructure provides a verification pass that may be used
356 to verify that an LLVM module is well formed. This pass is automatically run
357 by the parser after parsing input assembly and by the optimizer before it
358 outputs bitcode. The violations pointed out by the verifier pass indicate
359 bugs in transformation passes or input to the parser.</p>
360
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]361</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]363<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]365<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]366<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]367<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]369<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]371<p>LLVM identifiers come in two basic types: global and local. Global
372 identifiers (functions, global variables) begin with the <tt>'@'</tt>
373 character. Local identifiers (register names, types) begin with
374 the <tt>'%'</tt> character. Additionally, there are three different formats
375 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]376
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]377<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]378 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]379 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
380 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
381 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
382 other characters in their names can be surrounded with quotes. Special
383 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
384 ASCII code for the character in hexadecimal. In this way, any character
385 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]386
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]387 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]388 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]389
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]390 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]391 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]392</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]393
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]394<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]395 don't need to worry about name clashes with reserved words, and the set of
396 reserved words may be expanded in the future without penalty. Additionally,
397 unnamed identifiers allow a compiler to quickly come up with a temporary
398 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]400<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]401 languages. There are keywords for different opcodes
402 ('<tt><a href="#i_add">add</a></tt>',
403 '<tt><a href="#i_bitcast">bitcast</a></tt>',
404 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
405 ('<tt><a href="#t_void">void</a></tt>',
406 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
407 reserved words cannot conflict with variable names, because none of them
408 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409
410<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]411 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]412
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]413<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]414
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]415<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]416<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]417%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]418</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]419</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]420
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]421<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]422
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]423<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]424<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]425%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]427</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]429<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]433<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
434<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
435%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]437</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]439<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
440 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]442<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]443 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]444 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445
446 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]447 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]449 <li>Unnamed temporaries are numbered sequentially</li>
450</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]452<p>...and it also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]453 demonstrating instructions, we will follow an instruction with a comment that
454 defines the type and name of value produced. Comments are shown in italic
455 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]457</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]458
459<!-- *********************************************************************** -->
460<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
461<!-- *********************************************************************** -->
462
463<!-- ======================================================================= -->
464<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
465</div>
466
467<div class="doc_text">
468
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469<p>LLVM programs are composed of "Module"s, each of which is a translation unit
470 of the input programs. Each module consists of functions, global variables,
471 and symbol table entries. Modules may be combined together with the LLVM
472 linker, which merges function (and global variable) definitions, resolves
473 forward declarations, and merges symbol table entries. Here is an example of
474 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]475
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]476<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]477<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]478<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
479 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<i>; External declaration of the puts function</i>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]482<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483
484<i>; Definition of main function</i>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]485define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]486 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]487 %cast210 = <a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]488 href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489
490 <i>; Call puts function to write out the string to stdout...</i>
491 <a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]492 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]494 href="#i_ret">ret</a> i32 0<br>}<br>
495</pre>
496</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]498<p>This example is made up of a <a href="#globalvars">global variable</a> named
499 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
500 a <a href="#functionstructure">function definition</a> for
501 "<tt>main</tt>".</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]503<p>In general, a module is made up of a list of global values, where both
504 functions and global variables are global values. Global values are
505 represented by a pointer to a memory location (in this case, a pointer to an
506 array of char, and a pointer to a function), and have one of the
507 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]508
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
513 <a name="linkage">Linkage Types</a>
514</div>
515
516<div class="doc_text">
517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]518<p>All Global Variables and Functions have one of the following types of
519 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
521<dl>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523 <dd>Global values with private linkage are only directly accessible by objects
524 in the current module. In particular, linking code into a module with an
525 private global value may cause the private to be renamed as necessary to
526 avoid collisions. Because the symbol is private to the module, all
527 references can be updated. This doesn't show up in any symbol table in the
528 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]529
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]531 <dd>Similar to private, but the symbol is passed through the assembler and
532 removed by the linker after evaluation.</dd>
533
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]534 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]535 <dd>Similar to private, but the value shows as a local symbol
536 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
537 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]539 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]540 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]541 into the object file corresponding to the LLVM module. They exist to
542 allow inlining and other optimizations to take place given knowledge of
543 the definition of the global, which is known to be somewhere outside the
544 module. Globals with <tt>available_externally</tt> linkage are allowed to
545 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
546 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]547
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]549 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]550 the same name when linkage occurs. This is typically used to implement
551 inline functions, templates, or other code which must be generated in each
552 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
553 allowed to be discarded.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]554
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]556 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
557 <tt>linkonce</tt> linkage, except that unreferenced globals with
558 <tt>weak</tt> linkage may not be discarded. This is used for globals that
559 are declared "weak" in C source code.</dd>
560
561 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
562 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
563 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
564 global scope.
565 Symbols with "<tt>common</tt>" linkage are merged in the same way as
566 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]567 <tt>common</tt> symbols may not have an explicit section,
568 must have a zero initializer, and may not be marked '<a
569 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
570 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]571
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]572
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]573 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]574 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]575 pointer to array type. When two global variables with appending linkage
576 are linked together, the two global arrays are appended together. This is
577 the LLVM, typesafe, equivalent of having the system linker append together
578 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]579
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]581 <dd>The semantics of this linkage follow the ELF object file model: the symbol
582 is weak until linked, if not linked, the symbol becomes null instead of
583 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]584
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]586 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]587 <dd>Some languages allow differing globals to be merged, such as two functions
588 with different semantics. Other languages, such as <tt>C++</tt>, ensure
589 that only equivalent globals are ever merged (the "one definition rule" -
590 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
591 and <tt>weak_odr</tt> linkage types to indicate that the global will only
592 be merged with equivalent globals. These linkage types are otherwise the
593 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]594
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]595 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]596 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]597 visible, meaning that it participates in linkage and can be used to
598 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]599</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]600
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]601<p>The next two types of linkage are targeted for Microsoft Windows platform
602 only. They are designed to support importing (exporting) symbols from (to)
603 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]604
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]605<dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]606 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]607 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]608 or variable via a global pointer to a pointer that is set up by the DLL
609 exporting the symbol. On Microsoft Windows targets, the pointer name is
610 formed by combining <code>__imp_</code> and the function or variable
611 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]612
613 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]614 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]615 pointer to a pointer in a DLL, so that it can be referenced with the
616 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
617 name is formed by combining <code>__imp_</code> and the function or
618 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]619</dl>
620
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]621<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
622 another module defined a "<tt>.LC0</tt>" variable and was linked with this
623 one, one of the two would be renamed, preventing a collision. Since
624 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
625 declarations), they are accessible outside of the current module.</p>
626
627<p>It is illegal for a function <i>declaration</i> to have any linkage type
628 other than "externally visible", <tt>dllimport</tt>
629 or <tt>extern_weak</tt>.</p>
630
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]631<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]632 or <tt>weak_odr</tt> linkages.</p>
633
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]634</div>
635
636<!-- ======================================================================= -->
637<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]638 <a name="callingconv">Calling Conventions</a>
639</div>
640
641<div class="doc_text">
642
643<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]644 and <a href="#i_invoke">invokes</a> can all have an optional calling
645 convention specified for the call. The calling convention of any pair of
646 dynamic caller/callee must match, or the behavior of the program is
647 undefined. The following calling conventions are supported by LLVM, and more
648 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]649
650<dl>
651 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]652 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]653 specified) matches the target C calling conventions. This calling
654 convention supports varargs function calls and tolerates some mismatch in
655 the declared prototype and implemented declaration of the function (as
656 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]657
658 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]659 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]660 (e.g. by passing things in registers). This calling convention allows the
661 target to use whatever tricks it wants to produce fast code for the
662 target, without having to conform to an externally specified ABI
663 (Application Binary Interface). Implementations of this convention should
664 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
665 optimization</a> to be supported. This calling convention does not
666 support varargs and requires the prototype of all callees to exactly match
667 the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]668
669 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]670 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]671 as possible under the assumption that the call is not commonly executed.
672 As such, these calls often preserve all registers so that the call does
673 not break any live ranges in the caller side. This calling convention
674 does not support varargs and requires the prototype of all callees to
675 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]676
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]677 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]678 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]679 target-specific calling conventions to be used. Target specific calling
680 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]681</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]682
683<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]684 support Pascal conventions or any other well-known target-independent
685 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]686
687</div>
688
689<!-- ======================================================================= -->
690<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]691 <a name="visibility">Visibility Styles</a>
692</div>
693
694<div class="doc_text">
695
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]696<p>All Global Variables and Functions have one of the following visibility
697 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]698
699<dl>
700 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]701 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]702 that the declaration is visible to other modules and, in shared libraries,
703 means that the declared entity may be overridden. On Darwin, default
704 visibility means that the declaration is visible to other modules. Default
705 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]706
707 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]708 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]709 object if they are in the same shared object. Usually, hidden visibility
710 indicates that the symbol will not be placed into the dynamic symbol
711 table, so no other module (executable or shared library) can reference it
712 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]713
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]714 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]715 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]716 the dynamic symbol table, but that references within the defining module
717 will bind to the local symbol. That is, the symbol cannot be overridden by
718 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]719</dl>
720
721</div>
722
723<!-- ======================================================================= -->
724<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]725 <a name="namedtypes">Named Types</a>
726</div>
727
728<div class="doc_text">
729
730<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]731 it easier to read the IR and make the IR more condensed (particularly when
732 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]733
734<div class="doc_code">
735<pre>
736%mytype = type { %mytype*, i32 }
737</pre>
738</div>
739
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]740<p>You may give a name to any <a href="#typesystem">type</a> except
741 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
742 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]743
744<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]745 and that you can therefore specify multiple names for the same type. This
746 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
747 uses structural typing, the name is not part of the type. When printing out
748 LLVM IR, the printer will pick <em>one name</em> to render all types of a
749 particular shape. This means that if you have code where two different
750 source types end up having the same LLVM type, that the dumper will sometimes
751 print the "wrong" or unexpected type. This is an important design point and
752 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]753
754</div>
755
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]756<!-- ======================================================================= -->
757<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]758 <a name="globalvars">Global Variables</a>
759</div>
760
761<div class="doc_text">
762
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]763<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]764 instead of run-time. Global variables may optionally be initialized, may
765 have an explicit section to be placed in, and may have an optional explicit
766 alignment specified. A variable may be defined as "thread_local", which
767 means that it will not be shared by threads (each thread will have a
768 separated copy of the variable). A variable may be defined as a global
769 "constant," which indicates that the contents of the variable
770 will <b>never</b> be modified (enabling better optimization, allowing the
771 global data to be placed in the read-only section of an executable, etc).
772 Note that variables that need runtime initialization cannot be marked
773 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]774
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]775<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
776 constant, even if the final definition of the global is not. This capability
777 can be used to enable slightly better optimization of the program, but
778 requires the language definition to guarantee that optimizations based on the
779 'constantness' are valid for the translation units that do not include the
780 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]781
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]782<p>As SSA values, global variables define pointer values that are in scope
783 (i.e. they dominate) all basic blocks in the program. Global variables
784 always define a pointer to their "content" type because they describe a
785 region of memory, and all memory objects in LLVM are accessed through
786 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]787
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]788<p>A global variable may be declared to reside in a target-specific numbered
789 address space. For targets that support them, address spaces may affect how
790 optimizations are performed and/or what target instructions are used to
791 access the variable. The default address space is zero. The address space
792 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]793
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]794<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]795 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]796
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]797<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]798 the alignment is set to zero, the alignment of the global is set by the
799 target to whatever it feels convenient. If an explicit alignment is
800 specified, the global is forced to have at least that much alignment. All
801 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]802
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]803<p>For example, the following defines a global in a numbered address space with
804 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]805
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]806<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]807<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]808@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]809</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]810</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]811
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]812</div>
813
814
815<!-- ======================================================================= -->
816<div class="doc_subsection">
817 <a name="functionstructure">Functions</a>
818</div>
819
820<div class="doc_text">
821
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]822<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
823 optional <a href="#linkage">linkage type</a>, an optional
824 <a href="#visibility">visibility style</a>, an optional
825 <a href="#callingconv">calling convention</a>, a return type, an optional
826 <a href="#paramattrs">parameter attribute</a> for the return type, a function
827 name, a (possibly empty) argument list (each with optional
828 <a href="#paramattrs">parameter attributes</a>), optional
829 <a href="#fnattrs">function attributes</a>, an optional section, an optional
830 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
831 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]832
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]833<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
834 optional <a href="#linkage">linkage type</a>, an optional
835 <a href="#visibility">visibility style</a>, an optional
836 <a href="#callingconv">calling convention</a>, a return type, an optional
837 <a href="#paramattrs">parameter attribute</a> for the return type, a function
838 name, a possibly empty list of arguments, an optional alignment, and an
839 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]840
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]841<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]842 (Control Flow Graph) for the function. Each basic block may optionally start
843 with a label (giving the basic block a symbol table entry), contains a list
844 of instructions, and ends with a <a href="#terminators">terminator</a>
845 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]846
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]847<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]848 executed on entrance to the function, and it is not allowed to have
849 predecessor basic blocks (i.e. there can not be any branches to the entry
850 block of a function). Because the block can have no predecessors, it also
851 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]852
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]853<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]854 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]855
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]856<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]857 the alignment is set to zero, the alignment of the function is set by the
858 target to whatever it feels convenient. If an explicit alignment is
859 specified, the function is forced to have at least that much alignment. All
860 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]861
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]862<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]863<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]864<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]865define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]866 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
867 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
868 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
869 [<a href="#gc">gc</a>] { ... }
870</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]871</div>
872
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]873</div>
874
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]875<!-- ======================================================================= -->
876<div class="doc_subsection">
877 <a name="aliasstructure">Aliases</a>
878</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]879
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]880<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]881
882<p>Aliases act as "second name" for the aliasee value (which can be either
883 function, global variable, another alias or bitcast of global value). Aliases
884 may have an optional <a href="#linkage">linkage type</a>, and an
885 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]886
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]887<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]888<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]889<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]890@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]891</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]892</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]893
894</div>
895
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]896<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]897<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]898
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]899<div class="doc_text">
900
901<p>The return type and each parameter of a function type may have a set of
902 <i>parameter attributes</i> associated with them. Parameter attributes are
903 used to communicate additional information about the result or parameters of
904 a function. Parameter attributes are considered to be part of the function,
905 not of the function type, so functions with different parameter attributes
906 can have the same function type.</p>
907
908<p>Parameter attributes are simple keywords that follow the type specified. If
909 multiple parameter attributes are needed, they are space separated. For
910 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]911
912<div class="doc_code">
913<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]914declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]915declare i32 @atoi(i8 zeroext)
916declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]917</pre>
918</div>
919
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]920<p>Note that any attributes for the function result (<tt>nounwind</tt>,
921 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]922
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]923<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]924
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]925<dl>
926 <dt><tt>zeroext</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]927 <dd>This indicates to the code generator that the parameter or return value
928 should be zero-extended to a 32-bit value by the caller (for a parameter)
929 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]930
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]931 <dt><tt>signext</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]932 <dd>This indicates to the code generator that the parameter or return value
933 should be sign-extended to a 32-bit value by the caller (for a parameter)
934 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]935
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]936 <dt><tt>inreg</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]937 <dd>This indicates that this parameter or return value should be treated in a
938 special target-dependent fashion during while emitting code for a function
939 call or return (usually, by putting it in a register as opposed to memory,
940 though some targets use it to distinguish between two different kinds of
941 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]942
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]943 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]944 <dd>This indicates that the pointer parameter should really be passed by value
945 to the function. The attribute implies that a hidden copy of the pointee
946 is made between the caller and the callee, so the callee is unable to
947 modify the value in the callee. This attribute is only valid on LLVM
948 pointer arguments. It is generally used to pass structs and arrays by
949 value, but is also valid on pointers to scalars. The copy is considered
950 to belong to the caller not the callee (for example,
951 <tt><a href="#readonly">readonly</a></tt> functions should not write to
952 <tt>byval</tt> parameters). This is not a valid attribute for return
953 values. The byval attribute also supports specifying an alignment with
954 the align attribute. This has a target-specific effect on the code
955 generator that usually indicates a desired alignment for the synthesized
956 stack slot.</dd>
957
958 <dt><tt>sret</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]959 <dd>This indicates that the pointer parameter specifies the address of a
960 structure that is the return value of the function in the source program.
961 This pointer must be guaranteed by the caller to be valid: loads and
962 stores to the structure may be assumed by the callee to not to trap. This
963 may only be applied to the first parameter. This is not a valid attribute
964 for return values. </dd>
965
966 <dt><tt>noalias</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]967 <dd>This indicates that the pointer does not alias any global or any other
968 parameter. The caller is responsible for ensuring that this is the
969 case. On a function return value, <tt>noalias</tt> additionally indicates
970 that the pointer does not alias any other pointers visible to the
971 caller. For further details, please see the discussion of the NoAlias
972 response in
973 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
974 analysis</a>.</dd>
975
976 <dt><tt>nocapture</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates that the callee does not make any copies of the pointer
978 that outlive the callee itself. This is not a valid attribute for return
979 values.</dd>
980
981 <dt><tt>nest</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]982 <dd>This indicates that the pointer parameter can be excised using the
983 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
984 attribute for return values.</dd>
985</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]986
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]987</div>
988
989<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]990<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]991 <a name="gc">Garbage Collector Names</a>
992</div>
993
994<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]995
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]996<p>Each function may specify a garbage collector name, which is simply a
997 string:</p>
998
999<div class="doc_code">
1000<pre>
1001define void @f() gc "name" { ...
1002</pre>
1003</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1004
1005<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1006 collector which will cause the compiler to alter its output in order to
1007 support the named garbage collection algorithm.</p>
1008
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1009</div>
1010
1011<!-- ======================================================================= -->
1012<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1013 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1014</div>
1015
1016<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1017
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1018<p>Function attributes are set to communicate additional information about a
1019 function. Function attributes are considered to be part of the function, not
1020 of the function type, so functions with different parameter attributes can
1021 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1023<p>Function attributes are simple keywords that follow the type specified. If
1024 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1025
1026<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1027<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1028define void @f() noinline { ... }
1029define void @f() alwaysinline { ... }
1030define void @f() alwaysinline optsize { ... }
1031define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1032</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1033</div>
1034
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1035<dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1036 <dt><tt>alwaysinline</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This attribute indicates that the inliner should attempt to inline this
1038 function into callers whenever possible, ignoring any active inlining size
1039 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1040
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1041 <dt><tt>noinline</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This attribute indicates that the inliner should never inline this
1043 function in any situation. This attribute may not be used together with
1044 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1045
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1046 <dt><tt>optsize</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1047 <dd>This attribute suggests that optimization passes and code generator passes
1048 make choices that keep the code size of this function low, and otherwise
1049 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1050
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1051 <dt><tt>noreturn</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1052 <dd>This function attribute indicates that the function never returns
1053 normally. This produces undefined behavior at runtime if the function
1054 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1055
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1056 <dt><tt>nounwind</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1057 <dd>This function attribute indicates that the function never returns with an
1058 unwind or exceptional control flow. If the function does unwind, its
1059 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1060
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1061 <dt><tt>readnone</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1062 <dd>This attribute indicates that the function computes its result (or decides
1063 to unwind an exception) based strictly on its arguments, without
1064 dereferencing any pointer arguments or otherwise accessing any mutable
1065 state (e.g. memory, control registers, etc) visible to caller functions.
1066 It does not write through any pointer arguments
1067 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1068 changes any state visible to callers. This means that it cannot unwind
1069 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1070 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1071
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1072 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1073 <dd>This attribute indicates that the function does not write through any
1074 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1075 arguments) or otherwise modify any state (e.g. memory, control registers,
1076 etc) visible to caller functions. It may dereference pointer arguments
1077 and read state that may be set in the caller. A readonly function always
1078 returns the same value (or unwinds an exception identically) when called
1079 with the same set of arguments and global state. It cannot unwind an
1080 exception by calling the <tt>C++</tt> exception throwing methods, but may
1081 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1082
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1083 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1084 <dd>This attribute indicates that the function should emit a stack smashing
1085 protector. It is in the form of a "canary"&mdash;a random value placed on
1086 the stack before the local variables that's checked upon return from the
1087 function to see if it has been overwritten. A heuristic is used to
1088 determine if a function needs stack protectors or not.<br>
1089<br>
1090 If a function that has an <tt>ssp</tt> attribute is inlined into a
1091 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1092 function will have an <tt>ssp</tt> attribute.</dd>
1093
1094 <dt><tt>sspreq</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1095 <dd>This attribute indicates that the function should <em>always</em> emit a
1096 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1097 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1098<br>
1099 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1100 function that doesn't have an <tt>sspreq</tt> attribute or which has
1101 an <tt>ssp</tt> attribute, then the resulting function will have
1102 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1103
1104 <dt><tt>noredzone</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This attribute indicates that the code generator should not use a red
1106 zone, even if the target-specific ABI normally permits it.</dd>
1107
1108 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1109 <dd>This attributes disables implicit floating point instructions.</dd>
1110
1111 <dt><tt>naked</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1112 <dd>This attribute disables prologue / epilogue emission for the function.
1113 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1114</dl>
1115
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1116</div>
1117
1118<!-- ======================================================================= -->
1119<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1120 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1121</div>
1122
1123<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1124
1125<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1126 the GCC "file scope inline asm" blocks. These blocks are internally
1127 concatenated by LLVM and treated as a single unit, but may be separated in
1128 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1129
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1130<div class="doc_code">
1131<pre>
1132module asm "inline asm code goes here"
1133module asm "more can go here"
1134</pre>
1135</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1136
1137<p>The strings can contain any character by escaping non-printable characters.
1138 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1139 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1140
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1141<p>The inline asm code is simply printed to the machine code .s file when
1142 assembly code is generated.</p>
1143
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1144</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1145
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1146<!-- ======================================================================= -->
1147<div class="doc_subsection">
1148 <a name="datalayout">Data Layout</a>
1149</div>
1150
1151<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1152
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1153<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1154 data is to be laid out in memory. The syntax for the data layout is
1155 simply:</p>
1156
1157<div class="doc_code">
1158<pre>
1159target datalayout = "<i>layout specification</i>"
1160</pre>
1161</div>
1162
1163<p>The <i>layout specification</i> consists of a list of specifications
1164 separated by the minus sign character ('-'). Each specification starts with
1165 a letter and may include other information after the letter to define some
1166 aspect of the data layout. The specifications accepted are as follows:</p>
1167
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1168<dl>
1169 <dt><tt>E</tt></dt>
1170 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1171 bits with the most significance have the lowest address location.</dd>
1172
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1173 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1174 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1175 the bits with the least significance have the lowest address
1176 location.</dd>
1177
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1178 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1179 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1180 <i>preferred</i> alignments. All sizes are in bits. Specifying
1181 the <i>pref</i> alignment is optional. If omitted, the
1182 preceding <tt>:</tt> should be omitted too.</dd>
1183
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1184 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1185 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1186 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1187
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1188 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1189 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1190 <i>size</i>.</dd>
1191
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1192 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1193 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1194 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1195 (double).</dd>
1196
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1197 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1198 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <i>size</i>.</dd>
1200
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1201 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1202 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1203 <i>size</i>.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1204</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1205
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1206<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1207 default set of specifications which are then (possibly) overriden by the
1208 specifications in the <tt>datalayout</tt> keyword. The default specifications
1209 are given in this list:</p>
1210
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1211<ul>
1212 <li><tt>E</tt> - big endian</li>
1213 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1214 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1215 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1216 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1217 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1218 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1219 alignment of 64-bits</li>
1220 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1221 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1222 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1223 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1224 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1225 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1226</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1227
1228<p>When LLVM is determining the alignment for a given type, it uses the
1229 following rules:</p>
1230
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1231<ol>
1232 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1233 specification is used.</li>
1234
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1235 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1236 smallest integer type that is larger than the bitwidth of the sought type
1237 is used. If none of the specifications are larger than the bitwidth then
1238 the the largest integer type is used. For example, given the default
1239 specifications above, the i7 type will use the alignment of i8 (next
1240 largest) while both i65 and i256 will use the alignment of i64 (largest
1241 specified).</li>
1242
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1243 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1244 largest vector type that is smaller than the sought vector type will be
1245 used as a fall back. This happens because &lt;128 x double&gt; can be
1246 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1247</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1248
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1249</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1250
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1251<!-- ======================================================================= -->
1252<div class="doc_subsection">
1253 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1254</div>
1255
1256<div class="doc_text">
1257
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1258<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1259with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1260is undefined. Pointer values are associated with address ranges
1261according to the following rules:</p>
1262
1263<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1264 <li>A pointer value formed from a
1265 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1266 is associated with the addresses associated with the first operand
1267 of the <tt>getelementptr</tt>.</li>
1268 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1269 range of the variable's storage.</li>
1270 <li>The result value of an allocation instruction is associated with
1271 the address range of the allocated storage.</li>
1272 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1273 no address.</li>
1274 <li>A pointer value formed by an
1275 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1276 address ranges of all pointer values that contribute (directly or
1277 indirectly) to the computation of the pointer's value.</li>
1278 <li>The result value of a
1279 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1280 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1281 <li>An integer constant other than zero or a pointer value returned
1282 from a function not defined within LLVM may be associated with address
1283 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1284 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1285 allocated by mechanisms provided by LLVM.</li>
1286 </ul>
1287
1288<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1289<tt><a href="#i_load">load</a></tt> merely indicates the size and
1290alignment of the memory from which to load, as well as the
1291interpretation of the value. The first operand of a
1292<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1293and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1294
1295<p>Consequently, type-based alias analysis, aka TBAA, aka
1296<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1297LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1298additional information which specialized optimization passes may use
1299to implement type-based alias analysis.</p>
1300
1301</div>
1302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1303<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1304<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1305<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1306
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1307<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1308
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1309<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1310 intermediate representation. Being typed enables a number of optimizations
1311 to be performed on the intermediate representation directly, without having
1312 to do extra analyses on the side before the transformation. A strong type
1313 system makes it easier to read the generated code and enables novel analyses
1314 and transformations that are not feasible to perform on normal three address
1315 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1316
1317</div>
1318
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1319<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1320<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1321Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1322
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1323<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1324
1325<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1326
1327<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1328 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1329 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1330 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1331 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1332 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1333 </tr>
1334 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1335 <td><a href="#t_floating">floating point</a></td>
1336 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1337 </tr>
1338 <tr>
1339 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1340 <td><a href="#t_integer">integer</a>,
1341 <a href="#t_floating">floating point</a>,
1342 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1343 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1344 <a href="#t_struct">structure</a>,
1345 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1346 <a href="#t_label">label</a>,
1347 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1348 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1349 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1350 <tr>
1351 <td><a href="#t_primitive">primitive</a></td>
1352 <td><a href="#t_label">label</a>,
1353 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1354 <a href="#t_floating">floating point</a>,
1355 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1356 </tr>
1357 <tr>
1358 <td><a href="#t_derived">derived</a></td>
1359 <td><a href="#t_integer">integer</a>,
1360 <a href="#t_array">array</a>,
1361 <a href="#t_function">function</a>,
1362 <a href="#t_pointer">pointer</a>,
1363 <a href="#t_struct">structure</a>,
1364 <a href="#t_pstruct">packed structure</a>,
1365 <a href="#t_vector">vector</a>,
1366 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1367 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1368 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1369 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1370</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1371
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1372<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1373 important. Values of these types are the only ones which can be produced by
1374 instructions, passed as arguments, or used as operands to instructions.</p>
1375
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1376</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1377
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1378<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1379<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1380
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1381<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1382
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1383<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1384 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1385
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1386</div>
1387
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1388<!-- _______________________________________________________________________ -->
1389<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1390
1391<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1392
1393<table>
1394 <tbody>
1395 <tr><th>Type</th><th>Description</th></tr>
1396 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1397 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1398 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1399 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1400 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1401 </tbody>
1402</table>
1403
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1404</div>
1405
1406<!-- _______________________________________________________________________ -->
1407<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1408
1409<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1410
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1411<h5>Overview:</h5>
1412<p>The void type does not represent any value and has no size.</p>
1413
1414<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1415<pre>
1416 void
1417</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1418
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1419</div>
1420
1421<!-- _______________________________________________________________________ -->
1422<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1423
1424<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1425
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1426<h5>Overview:</h5>
1427<p>The label type represents code labels.</p>
1428
1429<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1430<pre>
1431 label
1432</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1433
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1434</div>
1435
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1436<!-- _______________________________________________________________________ -->
1437<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1438
1439<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1440
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1441<h5>Overview:</h5>
1442<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1443 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1444 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1445
1446<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1447<pre>
1448 metadata
1449</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1450
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1451</div>
1452
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1453
1454<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1455<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1457<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1458
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1459<p>The real power in LLVM comes from the derived types in the system. This is
1460 what allows a programmer to represent arrays, functions, pointers, and other
1461 useful types. Note that these derived types may be recursive: For example,
1462 it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1463
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1464</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1465
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1466<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1467<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1468
1469<div class="doc_text">
1470
1471<h5>Overview:</h5>
1472<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1473 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1474 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1475
1476<h5>Syntax:</h5>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1477<pre>
1478 iN
1479</pre>
1480
1481<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1482 value.</p>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1483
1484<h5>Examples:</h5>
1485<table class="layout">
Nick Lewyckyaab930a2009-05-24 02:46:06 +0000[diff] [blame]1486 <tr class="layout">
1487 <td class="left"><tt>i1</tt></td>
1488 <td class="left">a single-bit integer.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1489 </tr>
Nick Lewyckyaab930a2009-05-24 02:46:06 +0000[diff] [blame]1490 <tr class="layout">
1491 <td class="left"><tt>i32</tt></td>
1492 <td class="left">a 32-bit integer.</td>
1493 </tr>
1494 <tr class="layout">
1495 <td class="left"><tt>i1942652</tt></td>
1496 <td class="left">a really big integer of over 1 million bits.</td>
1497 </tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1498</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1499
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1500<p>Note that the code generator does not yet support large integer types to be
1501 used as function return types. The specific limit on how large a return type
1502 the code generator can currently handle is target-dependent; currently it's
1503 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1504
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1505</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1506
1507<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1508<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1509
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1510<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1511
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1512<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1513<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1514 sequentially in memory. The array type requires a size (number of elements)
1515 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1516
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1517<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1518<pre>
1519 [&lt;# elements&gt; x &lt;elementtype&gt;]
1520</pre>
1521
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1522<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1523 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1524
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1525<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1526<table class="layout">
1527 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1528 <td class="left"><tt>[40 x i32]</tt></td>
1529 <td class="left">Array of 40 32-bit integer values.</td>
1530 </tr>
1531 <tr class="layout">
1532 <td class="left"><tt>[41 x i32]</tt></td>
1533 <td class="left">Array of 41 32-bit integer values.</td>
1534 </tr>
1535 <tr class="layout">
1536 <td class="left"><tt>[4 x i8]</tt></td>
1537 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1538 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1539</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1540<p>Here are some examples of multidimensional arrays:</p>
1541<table class="layout">
1542 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1543 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1544 <td class="left">3x4 array of 32-bit integer values.</td>
1545 </tr>
1546 <tr class="layout">
1547 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1548 <td class="left">12x10 array of single precision floating point values.</td>
1549 </tr>
1550 <tr class="layout">
1551 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1552 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1553 </tr>
1554</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1555
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1556<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1557 length array. Normally, accesses past the end of an array are undefined in
1558 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1559 a special case, however, zero length arrays are recognized to be variable
1560 length. This allows implementation of 'pascal style arrays' with the LLVM
1561 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1562
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1563<p>Note that the code generator does not yet support large aggregate types to be
1564 used as function return types. The specific limit on how large an aggregate
1565 return type the code generator can currently handle is target-dependent, and
1566 also dependent on the aggregate element types.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1567
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1568</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1569
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1570<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1571<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1572
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1573<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1574
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1575<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1576<p>The function type can be thought of as a function signature. It consists of
1577 a return type and a list of formal parameter types. The return type of a
1578 function type is a scalar type, a void type, or a struct type. If the return
1579 type is a struct type then all struct elements must be of first class types,
1580 and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1581
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1582<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1583<pre>
1584 &lt;returntype list&gt; (&lt;parameter list&gt;)
1585</pre>
1586
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1587<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1588 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1589 which indicates that the function takes a variable number of arguments.
1590 Variable argument functions can access their arguments with
1591 the <a href="#int_varargs">variable argument handling intrinsic</a>
1592 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1593 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1594
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1595<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1596<table class="layout">
1597 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1598 <td class="left"><tt>i32 (i32)</tt></td>
1599 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1600 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1601 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1602 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1603 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1604 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1605 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1606 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1607 <tt>float</tt>.
1608 </td>
1609 </tr><tr class="layout">
1610 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1611 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1612 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1613 which returns an integer. This is the signature for <tt>printf</tt> in
1614 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1615 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1616 </tr><tr class="layout">
1617 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1618 <td class="left">A function taking an <tt>i32</tt>, returning two
1619 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1620 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1621 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1622</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1623
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1624</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1625
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1626<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1627<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1628
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1629<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1630
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1631<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1632<p>The structure type is used to represent a collection of data members together
1633 in memory. The packing of the field types is defined to match the ABI of the
1634 underlying processor. The elements of a structure may be any type that has a
1635 size.</p>
1636
1637<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1638 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1639 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1640
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1641<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1642<pre>
1643 { &lt;type list&gt; }
1644</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1645
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1646<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1647<table class="layout">
1648 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1649 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1650 <td class="left">A triple of three <tt>i32</tt> values</td>
1651 </tr><tr class="layout">
1652 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1653 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1654 second element is a <a href="#t_pointer">pointer</a> to a
1655 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1656 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1657 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1658</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1659
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1660<p>Note that the code generator does not yet support large aggregate types to be
1661 used as function return types. The specific limit on how large an aggregate
1662 return type the code generator can currently handle is target-dependent, and
1663 also dependent on the aggregate element types.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1664
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1665</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1666
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1667<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1668<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1669</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1670
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1671<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1672
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1673<h5>Overview:</h5>
1674<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1675 together in memory. There is no padding between fields. Further, the
1676 alignment of a packed structure is 1 byte. The elements of a packed
1677 structure may be any type that has a size.</p>
1678
1679<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1680 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1681 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1682
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1683<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1684<pre>
1685 &lt; { &lt;type list&gt; } &gt;
1686</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1687
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1688<h5>Examples:</h5>
1689<table class="layout">
1690 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1691 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1692 <td class="left">A triple of three <tt>i32</tt> values</td>
1693 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1694 <td class="left">
1695<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1696 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1697 second element is a <a href="#t_pointer">pointer</a> to a
1698 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1699 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1700 </tr>
1701</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1702
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1703</div>
1704
1705<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1706<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1707
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1708<div class="doc_text">
1709
1710<h5>Overview:</h5>
1711<p>As in many languages, the pointer type represents a pointer or reference to
1712 another object, which must live in memory. Pointer types may have an optional
1713 address space attribute defining the target-specific numbered address space
1714 where the pointed-to object resides. The default address space is zero.</p>
1715
1716<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1717 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1718
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1719<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1720<pre>
1721 &lt;type&gt; *
1722</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1723
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1724<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1725<table class="layout">
1726 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1727 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1728 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1729 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1730 </tr>
1731 <tr class="layout">
1732 <td class="left"><tt>i32 (i32 *) *</tt></td>
1733 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1734 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1735 <tt>i32</tt>.</td>
1736 </tr>
1737 <tr class="layout">
1738 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1739 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1740 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1741 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1742</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1743
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1744</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1745
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1746<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1747<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1748
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1749<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1750
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1751<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1752<p>A vector type is a simple derived type that represents a vector of elements.
1753 Vector types are used when multiple primitive data are operated in parallel
1754 using a single instruction (SIMD). A vector type requires a size (number of
1755 elements) and an underlying primitive data type. Vectors must have a power
1756 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1757 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1758
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1759<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1760<pre>
1761 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1762</pre>
1763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1764<p>The number of elements is a constant integer value; elementtype may be any
1765 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1766
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1767<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1768<table class="layout">
1769 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1770 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1771 <td class="left">Vector of 4 32-bit integer values.</td>
1772 </tr>
1773 <tr class="layout">
1774 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1775 <td class="left">Vector of 8 32-bit floating-point values.</td>
1776 </tr>
1777 <tr class="layout">
1778 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1779 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1780 </tr>
1781</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1782
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1783<p>Note that the code generator does not yet support large vector types to be
1784 used as function return types. The specific limit on how large a vector
1785 return type codegen can currently handle is target-dependent; currently it's
1786 often a few times longer than a hardware vector register.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1787
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1788</div>
1789
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1790<!-- _______________________________________________________________________ -->
1791<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1792<div class="doc_text">
1793
1794<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1795<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1796 corresponds (for example) to the C notion of a forward declared structure
1797 type. In LLVM, opaque types can eventually be resolved to any type (not just
1798 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1799
1800<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1801<pre>
1802 opaque
1803</pre>
1804
1805<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1806<table class="layout">
1807 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1808 <td class="left"><tt>opaque</tt></td>
1809 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1810 </tr>
1811</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1812
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1813</div>
1814
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1815<!-- ======================================================================= -->
1816<div class="doc_subsection">
1817 <a name="t_uprefs">Type Up-references</a>
1818</div>
1819
1820<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1821
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1822<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1823<p>An "up reference" allows you to refer to a lexically enclosing type without
1824 requiring it to have a name. For instance, a structure declaration may
1825 contain a pointer to any of the types it is lexically a member of. Example
1826 of up references (with their equivalent as named type declarations)
1827 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1828
1829<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1830 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1831 { \2 }* %y = type { %y }*
1832 \1* %z = type %z*
1833</pre>
1834
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1835<p>An up reference is needed by the asmprinter for printing out cyclic types
1836 when there is no declared name for a type in the cycle. Because the
1837 asmprinter does not want to print out an infinite type string, it needs a
1838 syntax to handle recursive types that have no names (all names are optional
1839 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1840
1841<h5>Syntax:</h5>
1842<pre>
1843 \&lt;level&gt;
1844</pre>
1845
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1846<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1847
1848<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1849<table class="layout">
1850 <tr class="layout">
1851 <td class="left"><tt>\1*</tt></td>
1852 <td class="left">Self-referential pointer.</td>
1853 </tr>
1854 <tr class="layout">
1855 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1856 <td class="left">Recursive structure where the upref refers to the out-most
1857 structure.</td>
1858 </tr>
1859</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1860
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1861</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1862
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1863<!-- *********************************************************************** -->
1864<div class="doc_section"> <a name="constants">Constants</a> </div>
1865<!-- *********************************************************************** -->
1866
1867<div class="doc_text">
1868
1869<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1870 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1871
1872</div>
1873
1874<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1875<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1876
1877<div class="doc_text">
1878
1879<dl>
1880 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1881 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1882 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1883
1884 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1885 <dd>Standard integers (such as '4') are constants of
1886 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1887 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1888
1889 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1890 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1891 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1892 notation (see below). The assembler requires the exact decimal value of a
1893 floating-point constant. For example, the assembler accepts 1.25 but
1894 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1895 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1896
1897 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1898 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1899 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1900</dl>
1901
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1902<p>The one non-intuitive notation for constants is the hexadecimal form of
1903 floating point constants. For example, the form '<tt>double
1904 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1905 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1906 constants are required (and the only time that they are generated by the
1907 disassembler) is when a floating point constant must be emitted but it cannot
1908 be represented as a decimal floating point number in a reasonable number of
1909 digits. For example, NaN's, infinities, and other special values are
1910 represented in their IEEE hexadecimal format so that assembly and disassembly
1911 do not cause any bits to change in the constants.</p>
1912
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1913<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1914 represented using the 16-digit form shown above (which matches the IEEE754
1915 representation for double); float values must, however, be exactly
1916 representable as IEE754 single precision. Hexadecimal format is always used
1917 for long double, and there are three forms of long double. The 80-bit format
1918 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1919 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1920 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1921 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1922 currently supported target uses this format. Long doubles will only work if
1923 they match the long double format on your target. All hexadecimal formats
1924 are big-endian (sign bit at the left).</p>
1925
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1926</div>
1927
1928<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1929<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]1930<a name="aggregateconstants"></a> <!-- old anchor -->
1931<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1932</div>
1933
1934<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1935
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1936<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1937 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1938
1939<dl>
1940 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1941 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1942 type definitions (a comma separated list of elements, surrounded by braces
1943 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1944 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1945 Structure constants must have <a href="#t_struct">structure type</a>, and
1946 the number and types of elements must match those specified by the
1947 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1948
1949 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1950 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1951 definitions (a comma separated list of elements, surrounded by square
1952 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1953 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1954 the number and types of elements must match those specified by the
1955 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1956
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1957 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1958 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1959 definitions (a comma separated list of elements, surrounded by
1960 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1961 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1962 have <a href="#t_vector">vector type</a>, and the number and types of
1963 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1964
1965 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1966 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1967 value to zero of <em>any</em> type, including scalar and aggregate types.
1968 This is often used to avoid having to print large zero initializers
1969 (e.g. for large arrays) and is always exactly equivalent to using explicit
1970 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]1971
1972 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]1973 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1974 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1975 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1976 be interpreted as part of the instruction stream, metadata is a place to
1977 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1978</dl>
1979
1980</div>
1981
1982<!-- ======================================================================= -->
1983<div class="doc_subsection">
1984 <a name="globalconstants">Global Variable and Function Addresses</a>
1985</div>
1986
1987<div class="doc_text">
1988
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1989<p>The addresses of <a href="#globalvars">global variables</a>
1990 and <a href="#functionstructure">functions</a> are always implicitly valid
1991 (link-time) constants. These constants are explicitly referenced when
1992 the <a href="#identifiers">identifier for the global</a> is used and always
1993 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1994 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1995
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1996<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1997<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1998@X = global i32 17
1999@Y = global i32 42
2000@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2001</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2002</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2003
2004</div>
2005
2006<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2007<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2008<div class="doc_text">
2009
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2010<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2011 specific value. Undefined values may be of any type and be used anywhere a
2012 constant is permitted.</p>
2013
2014<p>Undefined values indicate to the compiler that the program is well defined no
2015 matter what value is used, giving the compiler more freedom to optimize.</p>
2016
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2017</div>
2018
2019<!-- ======================================================================= -->
2020<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2021</div>
2022
2023<div class="doc_text">
2024
2025<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2026 to be used as constants. Constant expressions may be of
2027 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2028 operation that does not have side effects (e.g. load and call are not
2029 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2030
2031<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2032 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2033 <dd>Truncate a constant to another type. The bit size of CST must be larger
2034 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2035
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2036 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2037 <dd>Zero extend a constant to another type. The bit size of CST must be
2038 smaller or equal to the bit size of TYPE. Both types must be
2039 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2040
2041 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2042 <dd>Sign extend a constant to another type. The bit size of CST must be
2043 smaller or equal to the bit size of TYPE. Both types must be
2044 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2045
2046 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2047 <dd>Truncate a floating point constant to another floating point type. The
2048 size of CST must be larger than the size of TYPE. Both types must be
2049 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2050
2051 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2052 <dd>Floating point extend a constant to another type. The size of CST must be
2053 smaller or equal to the size of TYPE. Both types must be floating
2054 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2055
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2056 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2057 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2058 constant. TYPE must be a scalar or vector integer type. CST must be of
2059 scalar or vector floating point type. Both CST and TYPE must be scalars,
2060 or vectors of the same number of elements. If the value won't fit in the
2061 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2062
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2063 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2064 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2065 constant. TYPE must be a scalar or vector integer type. CST must be of
2066 scalar or vector floating point type. Both CST and TYPE must be scalars,
2067 or vectors of the same number of elements. If the value won't fit in the
2068 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2069
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2070 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2071 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2072 constant. TYPE must be a scalar or vector floating point type. CST must be
2073 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2074 vectors of the same number of elements. If the value won't fit in the
2075 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2076
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2077 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2078 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2079 constant. TYPE must be a scalar or vector floating point type. CST must be
2080 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2081 vectors of the same number of elements. If the value won't fit in the
2082 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2083
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2084 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2085 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2086 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2087 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2088 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2089
2090 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2091 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2092 type. CST must be of integer type. The CST value is zero extended,
2093 truncated, or unchanged to make it fit in a pointer size. This one is
2094 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2095
2096 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2097 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2098 are the same as those for the <a href="#i_bitcast">bitcast
2099 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2100
2101 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2102 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2103 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2104 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2105 instruction, the index list may have zero or more indexes, which are
2106 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2107
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2108 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2109 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2110
2111 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2112 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2113
2114 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2115 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2116
2117 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2118 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2119 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2120
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2121 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2122 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2123 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2124
2125 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2126 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2127 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2128
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2129 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2130 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2131 be any of the <a href="#binaryops">binary</a>
2132 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2133 on operands are the same as those for the corresponding instruction
2134 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2135</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2136
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2137</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2138
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2139<!-- ======================================================================= -->
2140<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2141</div>
2142
2143<div class="doc_text">
2144
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2145<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2146 stream without affecting the behaviour of the program. There are two
2147 metadata primitives, strings and nodes. All metadata has the
2148 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2149 point ('<tt>!</tt>').</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2150
2151<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2152 any character by escaping non-printable characters with "\xx" where "xx" is
2153 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2154
2155<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2156 (a comma separated list of elements, surrounded by braces and preceeded by an
2157 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2158 10}</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2159
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2160<p>A metadata node will attempt to track changes to the values it holds. In the
2161 event that a value is deleted, it will be replaced with a typeless
2162 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckyb8f9b7a2009-05-10 20:57:05 +0000[diff] [blame]2163
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2164<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2165 the program that isn't available in the instructions, or that isn't easily
2166 computable. Similarly, the code generator may expect a certain metadata
2167 format to be used to express debugging information.</p>
2168
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2169</div>
2170
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2171<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2172<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2173<!-- *********************************************************************** -->
2174
2175<!-- ======================================================================= -->
2176<div class="doc_subsection">
2177<a name="inlineasm">Inline Assembler Expressions</a>
2178</div>
2179
2180<div class="doc_text">
2181
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2182<p>LLVM supports inline assembler expressions (as opposed
2183 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2184 a special value. This value represents the inline assembler as a string
2185 (containing the instructions to emit), a list of operand constraints (stored
2186 as a string), and a flag that indicates whether or not the inline asm
2187 expression has side effects. An example inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2188
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2189<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2190<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2191i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2192</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2193</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2194
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2195<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2196 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2197 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2198
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2199<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2200<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2201%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2202</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2203</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2204
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2205<p>Inline asms with side effects not visible in the constraint list must be
2206 marked as having side effects. This is done through the use of the
2207 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2208
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2209<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2210<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2211call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2212</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2213</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2214
2215<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2216 documented here. Constraints on what can be done (e.g. duplication, moving,
2217 etc need to be documented). This is probably best done by reference to
2218 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2219
2220</div>
2221
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2222
2223<!-- *********************************************************************** -->
2224<div class="doc_section">
2225 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2226</div>
2227<!-- *********************************************************************** -->
2228
2229<p>LLVM has a number of "magic" global variables that contain data that affect
2230code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2231of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2232section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2233by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2234
2235<!-- ======================================================================= -->
2236<div class="doc_subsection">
2237<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2238</div>
2239
2240<div class="doc_text">
2241
2242<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2243href="#linkage_appending">appending linkage</a>. This array contains a list of
2244pointers to global variables and functions which may optionally have a pointer
2245cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2246
2247<pre>
2248 @X = global i8 4
2249 @Y = global i32 123
2250
2251 @llvm.used = appending global [2 x i8*] [
2252 i8* @X,
2253 i8* bitcast (i32* @Y to i8*)
2254 ], section "llvm.metadata"
2255</pre>
2256
2257<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2258compiler, assembler, and linker are required to treat the symbol as if there is
2259a reference to the global that it cannot see. For example, if a variable has
2260internal linkage and no references other than that from the <tt>@llvm.used</tt>
2261list, it cannot be deleted. This is commonly used to represent references from
2262inline asms and other things the compiler cannot "see", and corresponds to
2263"attribute((used))" in GNU C.</p>
2264
2265<p>On some targets, the code generator must emit a directive to the assembler or
2266object file to prevent the assembler and linker from molesting the symbol.</p>
2267
2268</div>
2269
2270<!-- ======================================================================= -->
2271<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2272<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2273</div>
2274
2275<div class="doc_text">
2276
2277<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2278<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2279touching the symbol. On targets that support it, this allows an intelligent
2280linker to optimize references to the symbol without being impeded as it would be
2281by <tt>@llvm.used</tt>.</p>
2282
2283<p>This is a rare construct that should only be used in rare circumstances, and
2284should not be exposed to source languages.</p>
2285
2286</div>
2287
2288<!-- ======================================================================= -->
2289<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2290<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2291</div>
2292
2293<div class="doc_text">
2294
2295<p>TODO: Describe this.</p>
2296
2297</div>
2298
2299<!-- ======================================================================= -->
2300<div class="doc_subsection">
2301<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2302</div>
2303
2304<div class="doc_text">
2305
2306<p>TODO: Describe this.</p>
2307
2308</div>
2309
2310
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2311<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2312<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2313<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2314
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2315<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2316
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2317<p>The LLVM instruction set consists of several different classifications of
2318 instructions: <a href="#terminators">terminator
2319 instructions</a>, <a href="#binaryops">binary instructions</a>,
2320 <a href="#bitwiseops">bitwise binary instructions</a>,
2321 <a href="#memoryops">memory instructions</a>, and
2322 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2323
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2324</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2326<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2327<div class="doc_subsection"> <a name="terminators">Terminator
2328Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2329
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2330<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2331
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2332<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2333 in a program ends with a "Terminator" instruction, which indicates which
2334 block should be executed after the current block is finished. These
2335 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2336 control flow, not values (the one exception being the
2337 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2338
2339<p>There are six different terminator instructions: the
2340 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2341 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2342 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2343 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2344 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2345 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2346
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2347</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2348
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2349<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2350<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2351Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2352
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2353<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2354
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2355<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2356<pre>
2357 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2358 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2359</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2360
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2361<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2362<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2363 a value) from a function back to the caller.</p>
2364
2365<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2366 value and then causes control flow, and one that just causes control flow to
2367 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2369<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2370<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2371 return value. The type of the return value must be a
2372 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2373
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2374<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2375 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2376 value or a return value with a type that does not match its type, or if it
2377 has a void return type and contains a '<tt>ret</tt>' instruction with a
2378 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2379
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2380<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2381<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2382 the calling function's context. If the caller is a
2383 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2384 instruction after the call. If the caller was an
2385 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2386 the beginning of the "normal" destination block. If the instruction returns
2387 a value, that value shall set the call or invoke instruction's return
2388 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2389
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2390<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2391<pre>
2392 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2393 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2394 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2395</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2396
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2397<p>Note that the code generator does not yet fully support large
2398 return values. The specific sizes that are currently supported are
2399 dependent on the target. For integers, on 32-bit targets the limit
2400 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2401 For aggregate types, the current limits are dependent on the element
2402 types; for example targets are often limited to 2 total integer
2403 elements and 2 total floating-point elements.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2404
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2405</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2406<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2407<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2408
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2409<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2410
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2411<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2412<pre>
2413 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2414</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2415
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2416<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2417<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2418 different basic block in the current function. There are two forms of this
2419 instruction, corresponding to a conditional branch and an unconditional
2420 branch.</p>
2421
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2422<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2423<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2424 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2425 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2426 target.</p>
2427
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2428<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2429<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2430 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2431 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2432 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2433
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2434<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2435<pre>
2436Test:
2437 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2438 br i1 %cond, label %IfEqual, label %IfUnequal
2439IfEqual:
2440 <a href="#i_ret">ret</a> i32 1
2441IfUnequal:
2442 <a href="#i_ret">ret</a> i32 0
2443</pre>
2444
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2445</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2446
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2447<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2448<div class="doc_subsubsection">
2449 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2450</div>
2451
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2452<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2453
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2454<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2455<pre>
2456 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2457</pre>
2458
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2459<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2460<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2461 several different places. It is a generalization of the '<tt>br</tt>'
2462 instruction, allowing a branch to occur to one of many possible
2463 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2464
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2465<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2466<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2467 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2468 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2469 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2470
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2471<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2472<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2473 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2474 is searched for the given value. If the value is found, control flow is
2475 transfered to the corresponding destination; otherwise, control flow is
2476 transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2477
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2478<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2479<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2480 <tt>switch</tt> instruction, this instruction may be code generated in
2481 different ways. For example, it could be generated as a series of chained
2482 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2483
2484<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2485<pre>
2486 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2487 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2488 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2489
2490 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2491 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2492
2493 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2494 switch i32 %val, label %otherwise [ i32 0, label %onzero
2495 i32 1, label %onone
2496 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2497</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2498
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2499</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2500
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2501<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2502<div class="doc_subsubsection">
2503 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2504</div>
2505
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2506<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2507
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2508<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2509<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2510 &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 Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]2511 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2512</pre>
2513
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2514<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2515<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2516 function, with the possibility of control flow transfer to either the
2517 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2518 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2519 control flow will return to the "normal" label. If the callee (or any
2520 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2521 instruction, control is interrupted and continued at the dynamically nearest
2522 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2523
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2524<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2525<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2526
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2527<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2528 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2529 convention</a> the call should use. If none is specified, the call
2530 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2531
2532 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2533 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2534 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2535
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2536 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2537 function value being invoked. In most cases, this is a direct function
2538 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2539 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2540
2541 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2542 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2543
2544 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2545 signature argument types. If the function signature indicates the
2546 function accepts a variable number of arguments, the extra arguments can
2547 be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2548
2549 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2550 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2551
2552 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2553 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2554
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2555 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2556 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2557 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2558</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2559
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2560<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2561<p>This instruction is designed to operate as a standard
2562 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2563 primary difference is that it establishes an association with a label, which
2564 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2565
2566<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2567 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2568 exception. Additionally, this is important for implementation of
2569 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2570
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2571<p>For the purposes of the SSA form, the definition of the value returned by the
2572 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2573 block to the "normal" label. If the callee unwinds then no return value is
2574 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2575
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2576<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2577<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2578 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2579 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2580 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2581 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2582</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2583
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2584</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2585
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2586<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2587
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2588<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2589Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2590
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2591<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2592
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2593<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2594<pre>
2595 unwind
2596</pre>
2597
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2598<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2599<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2600 at the first callee in the dynamic call stack which used
2601 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2602 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2603
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2604<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2605<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2606 immediately halt. The dynamic call stack is then searched for the
2607 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2608 Once found, execution continues at the "exceptional" destination block
2609 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2610 instruction in the dynamic call chain, undefined behavior results.</p>
2611
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2612</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2613
2614<!-- _______________________________________________________________________ -->
2615
2616<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2617Instruction</a> </div>
2618
2619<div class="doc_text">
2620
2621<h5>Syntax:</h5>
2622<pre>
2623 unreachable
2624</pre>
2625
2626<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2627<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2628 instruction is used to inform the optimizer that a particular portion of the
2629 code is not reachable. This can be used to indicate that the code after a
2630 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2631
2632<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2633<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2634
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2635</div>
2636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2637<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2638<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2639
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2640<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2641
2642<p>Binary operators are used to do most of the computation in a program. They
2643 require two operands of the same type, execute an operation on them, and
2644 produce a single value. The operands might represent multiple data, as is
2645 the case with the <a href="#t_vector">vector</a> data type. The result value
2646 has the same type as its operands.</p>
2647
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2648<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2649
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2650</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2651
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2652<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2653<div class="doc_subsubsection">
2654 <a name="i_add">'<tt>add</tt>' Instruction</a>
2655</div>
2656
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2657<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2658
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2659<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2660<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2661 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2662 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2663 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2664 &lt;result&gt; = nuw nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2665</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2666
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2667<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2668<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2669
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2670<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2671<p>The two arguments to the '<tt>add</tt>' instruction must
2672 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2673 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2675<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2676<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2677
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2678<p>If the sum has unsigned overflow, the result returned is the mathematical
2679 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2680
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2681<p>Because LLVM integers use a two's complement representation, this instruction
2682 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2683
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2684<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2685 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2686 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2687 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2688
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2689<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2690<pre>
2691 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2692</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2693
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2694</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2696<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2697<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2698 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2699</div>
2700
2701<div class="doc_text">
2702
2703<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2704<pre>
2705 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2706</pre>
2707
2708<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2709<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2710
2711<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2712<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2713 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2714 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2715
2716<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2717<p>The value produced is the floating point sum of the two operands.</p>
2718
2719<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2720<pre>
2721 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2722</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2723
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2724</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2725
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2726<!-- _______________________________________________________________________ -->
2727<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2728 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2729</div>
2730
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2731<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2732
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2733<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2734<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2735 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2736 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2737 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2738 &lt;result&gt; = nuw nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2739</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2740
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2741<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2742<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2743 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2744
2745<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2746 '<tt>neg</tt>' instruction present in most other intermediate
2747 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2748
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2749<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2750<p>The two arguments to the '<tt>sub</tt>' instruction must
2751 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2752 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2753
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2754<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2755<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2756
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2757<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2758 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2759 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2760
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2761<p>Because LLVM integers use a two's complement representation, this instruction
2762 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2763
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2764<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2765 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2766 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2767 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2768
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2769<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2770<pre>
2771 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2772 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2773</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2774
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2775</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2776
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2777<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2778<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2779 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2780</div>
2781
2782<div class="doc_text">
2783
2784<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2785<pre>
2786 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2787</pre>
2788
2789<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2790<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2791 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2792
2793<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2794 '<tt>fneg</tt>' instruction present in most other intermediate
2795 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2796
2797<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2798<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2799 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2800 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2801
2802<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2803<p>The value produced is the floating point difference of the two operands.</p>
2804
2805<h5>Example:</h5>
2806<pre>
2807 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2808 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2809</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2810
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2811</div>
2812
2813<!-- _______________________________________________________________________ -->
2814<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2815 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2816</div>
2817
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2818<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2819
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2820<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2821<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2822 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2823 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2824 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2825 &lt;result&gt; = nuw nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2826</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2827
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2828<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2829<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2830
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2831<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2832<p>The two arguments to the '<tt>mul</tt>' instruction must
2833 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2834 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2835
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2836<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2837<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2838
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2839<p>If the result of the multiplication has unsigned overflow, the result
2840 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2841 width of the result.</p>
2842
2843<p>Because LLVM integers use a two's complement representation, and the result
2844 is the same width as the operands, this instruction returns the correct
2845 result for both signed and unsigned integers. If a full product
2846 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2847 be sign-extended or zero-extended as appropriate to the width of the full
2848 product.</p>
2849
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2850<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2851 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2852 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2853 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2854
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2855<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2856<pre>
2857 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2858</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2859
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2860</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2861
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2862<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2863<div class="doc_subsubsection">
2864 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2865</div>
2866
2867<div class="doc_text">
2868
2869<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2870<pre>
2871 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2872</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2873
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2874<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2875<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2876
2877<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2878<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2879 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2880 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2881
2882<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2883<p>The value produced is the floating point product of the two operands.</p>
2884
2885<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2886<pre>
2887 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2888</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2889
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2890</div>
2891
2892<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2893<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2894</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2895
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2896<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2897
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2898<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2899<pre>
2900 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2901</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2902
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2903<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2904<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2905
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2906<h5>Arguments:</h5>
2907<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2908 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2909 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2910
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2911<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2912<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2913
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2914<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2915 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2916
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2917<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2918
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2919<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2920<pre>
2921 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2922</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2923
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2924</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2925
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2926<!-- _______________________________________________________________________ -->
2927<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2928</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2929
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2930<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2931
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2932<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2933<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2934 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2935 &lt;result&gt; = exact sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2936</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2937
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2938<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2939<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2940
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2941<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2942<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2943 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2944 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2945
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2946<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2947<p>The value produced is the signed integer quotient of the two operands rounded
2948 towards zero.</p>
2949
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2950<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2951 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2952
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2953<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2954 undefined behavior; this is a rare case, but can occur, for example, by doing
2955 a 32-bit division of -2147483648 by -1.</p>
2956
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]2957<p>If the <tt>exact</tt> keyword is present, the result value of the
2958 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2959 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2960
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2961<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2962<pre>
2963 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2964</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2965
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2966</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2967
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2968<!-- _______________________________________________________________________ -->
2969<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2970Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2971
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2972<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2973
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2974<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2975<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2976 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2977</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2978
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2979<h5>Overview:</h5>
2980<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2981
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2982<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2983<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2984 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2985 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2986
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2987<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2988<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2989
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2990<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2991<pre>
2992 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2993</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2994
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2995</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2996
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2997<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2998<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2999</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3000
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3001<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3002
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3003<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3004<pre>
3005 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3006</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3007
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3008<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3009<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3010 division of its two arguments.</p>
3011
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3012<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3013<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3014 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3015 values. Both arguments must have identical types.</p>
3016
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3017<h5>Semantics:</h5>
3018<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3019 This instruction always performs an unsigned division to get the
3020 remainder.</p>
3021
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3022<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3023 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3024
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3025<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3026
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3027<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3028<pre>
3029 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3030</pre>
3031
3032</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3033
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3034<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3035<div class="doc_subsubsection">
3036 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3037</div>
3038
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3039<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3040
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3041<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3042<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3043 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3044</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3045
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3046<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3047<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3048 division of its two operands. This instruction can also take
3049 <a href="#t_vector">vector</a> versions of the values in which case the
3050 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3051
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3052<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3053<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3054 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3055 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3056
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3057<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3058<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3059 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3060 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3061 a value. For more information about the difference,
3062 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3063 Math Forum</a>. For a table of how this is implemented in various languages,
3064 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3065 Wikipedia: modulo operation</a>.</p>
3066
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3067<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3068 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3069
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3070<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3071 Overflow also leads to undefined behavior; this is a rare case, but can
3072 occur, for example, by taking the remainder of a 32-bit division of
3073 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3074 lets srem be implemented using instructions that return both the result of
3075 the division and the remainder.)</p>
3076
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3077<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3078<pre>
3079 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3080</pre>
3081
3082</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3083
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3084<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3085<div class="doc_subsubsection">
3086 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3087
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3088<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3089
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3090<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3091<pre>
3092 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3093</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3094
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3095<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3096<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3097 its two operands.</p>
3098
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3099<h5>Arguments:</h5>
3100<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3102 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3103
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3104<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3105<p>This instruction returns the <i>remainder</i> of a division. The remainder
3106 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3107
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3108<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3109<pre>
3110 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3111</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3112
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3113</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3114
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3115<!-- ======================================================================= -->
3116<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3117Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3118
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3119<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3120
3121<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3122 program. They are generally very efficient instructions and can commonly be
3123 strength reduced from other instructions. They require two operands of the
3124 same type, execute an operation on them, and produce a single value. The
3125 resulting value is the same type as its operands.</p>
3126
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3127</div>
3128
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3129<!-- _______________________________________________________________________ -->
3130<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3131Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3132
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3133<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3134
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3135<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3136<pre>
3137 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3138</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3139
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3140<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3141<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3142 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3143
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3144<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3145<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3146 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3147 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3148
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3149<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3150<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3151 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3152 is (statically or dynamically) negative or equal to or larger than the number
3153 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3154 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3155 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3156
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3157<h5>Example:</h5>
3158<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3159 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3160 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3161 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3162 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3163 &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 Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3164</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3165
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3166</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3167
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3168<!-- _______________________________________________________________________ -->
3169<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3170Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3171
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3172<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3173
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3174<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3175<pre>
3176 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3177</pre>
3178
3179<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3181 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3182
3183<h5>Arguments:</h5>
3184<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3185 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3186 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3187
3188<h5>Semantics:</h5>
3189<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3190 significant bits of the result will be filled with zero bits after the shift.
3191 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3192 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3193 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3194 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3195
3196<h5>Example:</h5>
3197<pre>
3198 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3199 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3200 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3201 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3202 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3203 &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 Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3204</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3205
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3206</div>
3207
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3208<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3209<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3210Instruction</a> </div>
3211<div class="doc_text">
3212
3213<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3214<pre>
3215 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3216</pre>
3217
3218<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3219<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3220 operand shifted to the right a specified number of bits with sign
3221 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3222
3223<h5>Arguments:</h5>
3224<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3225 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3226 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3227
3228<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3229<p>This instruction always performs an arithmetic shift right operation, The
3230 most significant bits of the result will be filled with the sign bit
3231 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3232 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3233 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3234 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3235
3236<h5>Example:</h5>
3237<pre>
3238 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3239 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3240 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3241 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3242 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3243 &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 Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3244</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3245
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3246</div>
3247
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3248<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3249<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3250Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3251
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3252<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3253
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3254<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3255<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3256 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3257</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3260<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3261 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3262
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3263<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3264<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3265 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3266 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3267
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3268<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3269<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3270
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3271<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3272 <tbody>
3273 <tr>
3274 <td>In0</td>
3275 <td>In1</td>
3276 <td>Out</td>
3277 </tr>
3278 <tr>
3279 <td>0</td>
3280 <td>0</td>
3281 <td>0</td>
3282 </tr>
3283 <tr>
3284 <td>0</td>
3285 <td>1</td>
3286 <td>0</td>
3287 </tr>
3288 <tr>
3289 <td>1</td>
3290 <td>0</td>
3291 <td>0</td>
3292 </tr>
3293 <tr>
3294 <td>1</td>
3295 <td>1</td>
3296 <td>1</td>
3297 </tr>
3298 </tbody>
3299</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3300
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3301<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3302<pre>
3303 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3304 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3305 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3306</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3307</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3308<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3309<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3310
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3311<div class="doc_text">
3312
3313<h5>Syntax:</h5>
3314<pre>
3315 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3316</pre>
3317
3318<h5>Overview:</h5>
3319<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3320 two operands.</p>
3321
3322<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3323<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3324 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3325 values. Both arguments must have identical types.</p>
3326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3328<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3329
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3330<table border="1" cellspacing="0" cellpadding="4">
3331 <tbody>
3332 <tr>
3333 <td>In0</td>
3334 <td>In1</td>
3335 <td>Out</td>
3336 </tr>
3337 <tr>
3338 <td>0</td>
3339 <td>0</td>
3340 <td>0</td>
3341 </tr>
3342 <tr>
3343 <td>0</td>
3344 <td>1</td>
3345 <td>1</td>
3346 </tr>
3347 <tr>
3348 <td>1</td>
3349 <td>0</td>
3350 <td>1</td>
3351 </tr>
3352 <tr>
3353 <td>1</td>
3354 <td>1</td>
3355 <td>1</td>
3356 </tr>
3357 </tbody>
3358</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3359
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3360<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3361<pre>
3362 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3363 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3364 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3365</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3366
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3367</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3369<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3370<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3371Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3373<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3374
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3375<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3376<pre>
3377 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3378</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3379
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3380<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3381<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3382 its two operands. The <tt>xor</tt> is used to implement the "one's
3383 complement" operation, which is the "~" operator in C.</p>
3384
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3385<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3386<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3387 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3388 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3389
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3390<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3391<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3392
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3393<table border="1" cellspacing="0" cellpadding="4">
3394 <tbody>
3395 <tr>
3396 <td>In0</td>
3397 <td>In1</td>
3398 <td>Out</td>
3399 </tr>
3400 <tr>
3401 <td>0</td>
3402 <td>0</td>
3403 <td>0</td>
3404 </tr>
3405 <tr>
3406 <td>0</td>
3407 <td>1</td>
3408 <td>1</td>
3409 </tr>
3410 <tr>
3411 <td>1</td>
3412 <td>0</td>
3413 <td>1</td>
3414 </tr>
3415 <tr>
3416 <td>1</td>
3417 <td>1</td>
3418 <td>0</td>
3419 </tr>
3420 </tbody>
3421</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3422
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3423<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3424<pre>
3425 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3426 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3427 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3428 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3429</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3430
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3431</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3432
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3433<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3434<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3435 <a name="vectorops">Vector Operations</a>
3436</div>
3437
3438<div class="doc_text">
3439
3440<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3441 target-independent manner. These instructions cover the element-access and
3442 vector-specific operations needed to process vectors effectively. While LLVM
3443 does directly support these vector operations, many sophisticated algorithms
3444 will want to use target-specific intrinsics to take full advantage of a
3445 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3446
3447</div>
3448
3449<!-- _______________________________________________________________________ -->
3450<div class="doc_subsubsection">
3451 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3452</div>
3453
3454<div class="doc_text">
3455
3456<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3457<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3458 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3459</pre>
3460
3461<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3462<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3463 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3464
3465
3466<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3467<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3468 of <a href="#t_vector">vector</a> type. The second operand is an index
3469 indicating the position from which to extract the element. The index may be
3470 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3471
3472<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3473<p>The result is a scalar of the same type as the element type of
3474 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3475 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3476 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3477
3478<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3479<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3480 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3481</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3482
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3483</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3484
3485<!-- _______________________________________________________________________ -->
3486<div class="doc_subsubsection">
3487 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3488</div>
3489
3490<div class="doc_text">
3491
3492<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3493<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3494 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3495</pre>
3496
3497<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3498<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3499 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3500
3501<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3502<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3503 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3504 whose type must equal the element type of the first operand. The third
3505 operand is an index indicating the position at which to insert the value.
3506 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3507
3508<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3509<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3510 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3511 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3512 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3513
3514<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3515<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3516 %result = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3517</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3518
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3519</div>
3520
3521<!-- _______________________________________________________________________ -->
3522<div class="doc_subsubsection">
3523 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3524</div>
3525
3526<div class="doc_text">
3527
3528<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3529<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3530 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3531</pre>
3532
3533<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3534<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3535 from two input vectors, returning a vector with the same element type as the
3536 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3537
3538<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3539<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3540 with types that match each other. The third argument is a shuffle mask whose
3541 element type is always 'i32'. The result of the instruction is a vector
3542 whose length is the same as the shuffle mask and whose element type is the
3543 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3544
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3545<p>The shuffle mask operand is required to be a constant vector with either
3546 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3547
3548<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3549<p>The elements of the two input vectors are numbered from left to right across
3550 both of the vectors. The shuffle mask operand specifies, for each element of
3551 the result vector, which element of the two input vectors the result element
3552 gets. The element selector may be undef (meaning "don't care") and the
3553 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3554
3555<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3556<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3557 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3558 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3559 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3560 &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 Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3561 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3562 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3563 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3564 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3565</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3566
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3567</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3568
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3569<!-- ======================================================================= -->
3570<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3571 <a name="aggregateops">Aggregate Operations</a>
3572</div>
3573
3574<div class="doc_text">
3575
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3576<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3577
3578</div>
3579
3580<!-- _______________________________________________________________________ -->
3581<div class="doc_subsubsection">
3582 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3583</div>
3584
3585<div class="doc_text">
3586
3587<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3588<pre>
3589 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3590</pre>
3591
3592<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3593<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3594 or array element from an aggregate value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3595
3596<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3597<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3598 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3599 operands are constant indices to specify which value to extract in a similar
3600 manner as indices in a
3601 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3602
3603<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3604<p>The result is the value at the position in the aggregate specified by the
3605 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3606
3607<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3608<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3609 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3610</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3611
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3612</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3613
3614<!-- _______________________________________________________________________ -->
3615<div class="doc_subsubsection">
3616 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3617</div>
3618
3619<div class="doc_text">
3620
3621<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3622<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3623 &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 Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3624</pre>
3625
3626<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3627<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3628 array element in an aggregate.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3629
3630
3631<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3632<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3633 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3634 second operand is a first-class value to insert. The following operands are
3635 constant indices indicating the position at which to insert the value in a
3636 similar manner as indices in a
3637 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3638 value to insert must have the same type as the value identified by the
3639 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3640
3641<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3642<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3643 that of <tt>val</tt> except that the value at the position specified by the
3644 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3645
3646<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3647<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3648 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3649</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3650
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3651</div>
3652
3653
3654<!-- ======================================================================= -->
3655<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3656 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3657</div>
3658
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3659<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3660
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3661<p>A key design point of an SSA-based representation is how it represents
3662 memory. In LLVM, no memory locations are in SSA form, which makes things
3663 very simple. This section describes how to read, write, allocate, and free
3664 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3665
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3666</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3667
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3668<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3669<div class="doc_subsubsection">
3670 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3671</div>
3672
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3673<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3675<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3676<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3677 &lt;result&gt; = malloc &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3678</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3679
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3680<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3681<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3682 returns a pointer to it. The object is always allocated in the generic
3683 address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3684
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3685<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3686<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3687 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3688 system and returns a pointer of the appropriate type to the program. If
3689 "NumElements" is specified, it is the number of elements allocated, otherwise
3690 "NumElements" is defaulted to be one. If a constant alignment is specified,
3691 the value result of the allocation is guaranteed to be aligned to at least
3692 that boundary. If not specified, or if zero, the target can choose to align
3693 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3694
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3695<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3696
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3697<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3698<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3699 pointer is returned. The result of a zero byte allocation is undefined. The
3700 result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3701
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3702<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3703<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3704 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3705
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3706 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3707 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3708 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3709 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3710 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3711</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3712
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3713<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3714
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3715</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3716
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3717<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3718<div class="doc_subsubsection">
3719 <a name="i_free">'<tt>free</tt>' Instruction</a>
3720</div>
3721
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3722<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3723
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3724<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3725<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3726 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3727</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3729<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3730<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3731 to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3734<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3735 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3736
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3737<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3738<p>Access to the memory pointed to by the pointer is no longer defined after
3739 this instruction executes. If the pointer is null, the operation is a
3740 noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3741
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3742<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3743<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3744 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3745 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3746</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3747
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3748</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3749
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3750<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3751<div class="doc_subsubsection">
3752 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3753</div>
3754
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3755<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3756
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3757<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3758<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3759 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3760</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3761
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3762<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3763<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764 currently executing function, to be automatically released when this function
3765 returns to its caller. The object is always allocated in the generic address
3766 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3767
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3768<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3769<p>The '<tt>alloca</tt>' instruction
3770 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3771 runtime stack, returning a pointer of the appropriate type to the program.
3772 If "NumElements" is specified, it is the number of elements allocated,
3773 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3774 specified, the value result of the allocation is guaranteed to be aligned to
3775 at least that boundary. If not specified, or if zero, the target can choose
3776 to align the allocation on any convenient boundary compatible with the
3777 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3778
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3779<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3780
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3781<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]3782<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3783 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3784 memory is automatically released when the function returns. The
3785 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3786 variables that must have an address available. When the function returns
3787 (either with the <tt><a href="#i_ret">ret</a></tt>
3788 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3789 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3790
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3791<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3792<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3793 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3794 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3795 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3796 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3797</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3798
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3799</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3800
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3801<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3802<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3803Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3804
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3805<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3806
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3807<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3808<pre>
3809 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3810 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3811</pre>
3812
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3813<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3814<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3815
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3816<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3817<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3818 from which to load. The pointer must point to
3819 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3820 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3821 number or order of execution of this <tt>load</tt> with other
3822 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3823 instructions. </p>
3824
3825<p>The optional constant "align" argument specifies the alignment of the
3826 operation (that is, the alignment of the memory address). A value of 0 or an
3827 omitted "align" argument means that the operation has the preferential
3828 alignment for the target. It is the responsibility of the code emitter to
3829 ensure that the alignment information is correct. Overestimating the
3830 alignment results in an undefined behavior. Underestimating the alignment may
3831 produce less efficient code. An alignment of 1 is always safe.</p>
3832
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3833<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3834<p>The location of memory pointed to is loaded. If the value being loaded is of
3835 scalar type then the number of bytes read does not exceed the minimum number
3836 of bytes needed to hold all bits of the type. For example, loading an
3837 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3838 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3839 is undefined if the value was not originally written using a store of the
3840 same type.</p>
3841
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3842<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3843<pre>
3844 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3845 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3846 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3847</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3848
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3849</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3850
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3851<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3852<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3853Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3854
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3855<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3856
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3857<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3858<pre>
3859 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3860 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3861</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3862
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3863<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3864<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3865
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3866<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3867<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3868 and an address at which to store it. The type of the
3869 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3870 the <a href="#t_firstclass">first class</a> type of the
3871 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3872 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3873 or order of execution of this <tt>store</tt> with other
3874 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3875 instructions.</p>
3876
3877<p>The optional constant "align" argument specifies the alignment of the
3878 operation (that is, the alignment of the memory address). A value of 0 or an
3879 omitted "align" argument means that the operation has the preferential
3880 alignment for the target. It is the responsibility of the code emitter to
3881 ensure that the alignment information is correct. Overestimating the
3882 alignment results in an undefined behavior. Underestimating the alignment may
3883 produce less efficient code. An alignment of 1 is always safe.</p>
3884
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3885<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3886<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3887 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3888 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3889 does not exceed the minimum number of bytes needed to hold all bits of the
3890 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3891 writing a value of a type like <tt>i20</tt> with a size that is not an
3892 integral number of bytes, it is unspecified what happens to the extra bits
3893 that do not belong to the type, but they will typically be overwritten.</p>
3894
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3895<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3896<pre>
3897 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3898 store i32 3, i32* %ptr <i>; yields {void}</i>
3899 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3900</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3901
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3902</div>
3903
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3904<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3905<div class="doc_subsubsection">
3906 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3907</div>
3908
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3909<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3910
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3911<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3912<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3913 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]3914 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3915</pre>
3916
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3917<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3918<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3919 subelement of an aggregate data structure. It performs address calculation
3920 only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3921
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3922<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3923<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]3924 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3925 elements of the aggregate object are indexed. The interpretation of each
3926 index is dependent on the type being indexed into. The first index always
3927 indexes the pointer value given as the first argument, the second index
3928 indexes a value of the type pointed to (not necessarily the value directly
3929 pointed to, since the first index can be non-zero), etc. The first type
3930 indexed into must be a pointer value, subsequent types can be arrays, vectors
3931 and structs. Note that subsequent types being indexed into can never be
3932 pointers, since that would require loading the pointer before continuing
3933 calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3934
3935<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]3936 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3937 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]3938 vector, integers of any width are allowed, and they are not required to be
3939 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3940
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3941<p>For example, let's consider a C code fragment and how it gets compiled to
3942 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3943
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3944<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3945<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3946struct RT {
3947 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3948 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3949 char C;
3950};
3951struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3952 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3953 double Y;
3954 struct RT Z;
3955};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3956
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3957int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3958 return &amp;s[1].Z.B[5][13];
3959}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3960</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3961</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3962
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3963<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3964
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3965<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3966<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3967%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3968%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3969
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]3970define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3971entry:
3972 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3973 ret i32* %reg
3974}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3975</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3976</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3977
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3978<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3979<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3980 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3981 }</tt>' type, a structure. The second index indexes into the third element
3982 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3983 i8 }</tt>' type, another structure. The third index indexes into the second
3984 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3985 array. The two dimensions of the array are subscripted into, yielding an
3986 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3987 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3988
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3989<p>Note that it is perfectly legal to index partially through a structure,
3990 returning a pointer to an inner element. Because of this, the LLVM code for
3991 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3992
3993<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]3994 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3995 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3996 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3997 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3998 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3999 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4000 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4001 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4002</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4003
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4004<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4005 <tt>getelementptr</tt> is undefined if the base pointer is not an
4006 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame^]4007 that would be formed by successive addition of the offsets implied by the
4008 indices to the base address with infinitely precise arithmetic are not an
4009 <i>in bounds</i> address of that allocated object.
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4010 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame^]4011 that point into the object, plus the address one byte past the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4012
4013<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4014 the base address with silently-wrapping two's complement arithmetic, and
4015 the result value of the <tt>getelementptr</tt> may be outside the object
4016 pointed to by the base pointer. The result value may not necessarily be
4017 used to access memory though, even if it happens to point into allocated
4018 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4019 section for more information.</p>
4020
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4021<p>The getelementptr instruction is often confusing. For some more insight into
4022 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4023
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4024<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4025<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4026 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4027 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4028 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4029 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4030 <i>; yields i8*:eptr</i>
4031 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4032 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4033 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4034</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4035
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4036</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4037
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4038<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4039<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4040</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4041
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4042<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4043
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4044<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4045 which all take a single operand and a type. They perform various bit
4046 conversions on the operand.</p>
4047
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4048</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4049
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4050<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4051<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4052 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4053</div>
4054<div class="doc_text">
4055
4056<h5>Syntax:</h5>
4057<pre>
4058 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4059</pre>
4060
4061<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4062<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4063 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4064
4065<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4066<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4067 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4068 size and type of the result, which must be
4069 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4070 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4071 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4072
4073<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4074<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4075 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4076 source size must be larger than the destination size, <tt>trunc</tt> cannot
4077 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4078
4079<h5>Example:</h5>
4080<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4081 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4082 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4083 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4084</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4085
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4086</div>
4087
4088<!-- _______________________________________________________________________ -->
4089<div class="doc_subsubsection">
4090 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4091</div>
4092<div class="doc_text">
4093
4094<h5>Syntax:</h5>
4095<pre>
4096 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4097</pre>
4098
4099<h5>Overview:</h5>
4100<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4101 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4102
4103
4104<h5>Arguments:</h5>
4105<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4106 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4107 also be of <a href="#t_integer">integer</a> type. The bit size of the
4108 <tt>value</tt> must be smaller than the bit size of the destination type,
4109 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4110
4111<h5>Semantics:</h5>
4112<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4113 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4114
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4115<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4116
4117<h5>Example:</h5>
4118<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4119 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4120 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4121</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4122
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4123</div>
4124
4125<!-- _______________________________________________________________________ -->
4126<div class="doc_subsubsection">
4127 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4128</div>
4129<div class="doc_text">
4130
4131<h5>Syntax:</h5>
4132<pre>
4133 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4134</pre>
4135
4136<h5>Overview:</h5>
4137<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4138
4139<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4140<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4141 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4142 also be of <a href="#t_integer">integer</a> type. The bit size of the
4143 <tt>value</tt> must be smaller than the bit size of the destination type,
4144 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4145
4146<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4147<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4148 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4149 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4150
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4151<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4152
4153<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4154<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4155 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4156 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4157</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4158
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4159</div>
4160
4161<!-- _______________________________________________________________________ -->
4162<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4163 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4164</div>
4165
4166<div class="doc_text">
4167
4168<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4169<pre>
4170 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4171</pre>
4172
4173<h5>Overview:</h5>
4174<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4175 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4176
4177<h5>Arguments:</h5>
4178<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4179 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4180 to cast it to. The size of <tt>value</tt> must be larger than the size of
4181 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4182 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4183
4184<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4185<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4186 <a href="#t_floating">floating point</a> type to a smaller
4187 <a href="#t_floating">floating point</a> type. If the value cannot fit
4188 within the destination type, <tt>ty2</tt>, then the results are
4189 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4190
4191<h5>Example:</h5>
4192<pre>
4193 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4194 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4195</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4196
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4197</div>
4198
4199<!-- _______________________________________________________________________ -->
4200<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4201 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4202</div>
4203<div class="doc_text">
4204
4205<h5>Syntax:</h5>
4206<pre>
4207 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4208</pre>
4209
4210<h5>Overview:</h5>
4211<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4212 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4213
4214<h5>Arguments:</h5>
4215<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4216 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4217 a <a href="#t_floating">floating point</a> type to cast it to. The source
4218 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4219
4220<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4221<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4222 <a href="#t_floating">floating point</a> type to a larger
4223 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4224 used to make a <i>no-op cast</i> because it always changes bits. Use
4225 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4226
4227<h5>Example:</h5>
4228<pre>
4229 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4230 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4231</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4232
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4233</div>
4234
4235<!-- _______________________________________________________________________ -->
4236<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4237 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4238</div>
4239<div class="doc_text">
4240
4241<h5>Syntax:</h5>
4242<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4243 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4244</pre>
4245
4246<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4247<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4248 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4249
4250<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4251<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4252 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4253 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4254 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4255 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4256
4257<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4258<p>The '<tt>fptoui</tt>' instruction converts its
4259 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4260 towards zero) unsigned integer value. If the value cannot fit
4261 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4262
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4263<h5>Example:</h5>
4264<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4265 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4266 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4267 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4268</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4269
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4270</div>
4271
4272<!-- _______________________________________________________________________ -->
4273<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4274 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4275</div>
4276<div class="doc_text">
4277
4278<h5>Syntax:</h5>
4279<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4280 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4281</pre>
4282
4283<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4284<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4285 <a href="#t_floating">floating point</a> <tt>value</tt> to
4286 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4287
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4288<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4289<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4290 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4291 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4292 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4293 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4294
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4295<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4296<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4297 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4298 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4299 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4300
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4301<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4302<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4303 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4304 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4305 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4306</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4307
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4308</div>
4309
4310<!-- _______________________________________________________________________ -->
4311<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4312 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4313</div>
4314<div class="doc_text">
4315
4316<h5>Syntax:</h5>
4317<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4318 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4319</pre>
4320
4321<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4322<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4323 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4324
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4325<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4326<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4327 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4328 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4329 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4330 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4331
4332<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4333<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4334 integer quantity and converts it to the corresponding floating point
4335 value. If the value cannot fit in the floating point value, the results are
4336 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4337
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4338<h5>Example:</h5>
4339<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4340 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4341 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4342</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4343
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4344</div>
4345
4346<!-- _______________________________________________________________________ -->
4347<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4348 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4349</div>
4350<div class="doc_text">
4351
4352<h5>Syntax:</h5>
4353<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4354 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4355</pre>
4356
4357<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4358<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4359 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4360
4361<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4362<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4363 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4364 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4365 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4366 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4367
4368<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4369<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4370 quantity and converts it to the corresponding floating point value. If the
4371 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4372
4373<h5>Example:</h5>
4374<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4375 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4376 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4377</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4378
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4379</div>
4380
4381<!-- _______________________________________________________________________ -->
4382<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4383 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4384</div>
4385<div class="doc_text">
4386
4387<h5>Syntax:</h5>
4388<pre>
4389 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4390</pre>
4391
4392<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4393<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4394 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4395
4396<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4397<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4398 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4399 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4400
4401<h5>Semantics:</h5>
4402<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4403 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4404 truncating or zero extending that value to the size of the integer type. If
4405 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4406 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4407 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4408 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4409
4410<h5>Example:</h5>
4411<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4412 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4413 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4414</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4415
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4416</div>
4417
4418<!-- _______________________________________________________________________ -->
4419<div class="doc_subsubsection">
4420 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4421</div>
4422<div class="doc_text">
4423
4424<h5>Syntax:</h5>
4425<pre>
4426 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4427</pre>
4428
4429<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4430<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4431 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4432
4433<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4434<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4435 value to cast, and a type to cast it to, which must be a
4436 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4437
4438<h5>Semantics:</h5>
4439<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4440 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4441 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4442 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4443 than the size of a pointer then a zero extension is done. If they are the
4444 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4445
4446<h5>Example:</h5>
4447<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4448 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4449 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4450 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4451</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4452
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4453</div>
4454
4455<!-- _______________________________________________________________________ -->
4456<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4457 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4458</div>
4459<div class="doc_text">
4460
4461<h5>Syntax:</h5>
4462<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4463 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4464</pre>
4465
4466<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4467<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4468 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4469
4470<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4471<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4472 non-aggregate first class value, and a type to cast it to, which must also be
4473 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4474 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4475 identical. If the source type is a pointer, the destination type must also be
4476 a pointer. This instruction supports bitwise conversion of vectors to
4477 integers and to vectors of other types (as long as they have the same
4478 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4479
4480<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4481<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4482 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4483 this conversion. The conversion is done as if the <tt>value</tt> had been
4484 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4485 be converted to other pointer types with this instruction. To convert
4486 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4487 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4488
4489<h5>Example:</h5>
4490<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4491 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4492 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4493 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4494</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4495
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4496</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4497
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4498<!-- ======================================================================= -->
4499<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4500
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4501<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4502
4503<p>The instructions in this category are the "miscellaneous" instructions, which
4504 defy better classification.</p>
4505
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4506</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4507
4508<!-- _______________________________________________________________________ -->
4509<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4510</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4511
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4512<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4513
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4514<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4515<pre>
4516 &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 Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4517</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4518
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4519<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4520<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4521 boolean values based on comparison of its two integer, integer vector, or
4522 pointer operands.</p>
4523
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4524<h5>Arguments:</h5>
4525<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4526 the condition code indicating the kind of comparison to perform. It is not a
4527 value, just a keyword. The possible condition code are:</p>
4528
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4529<ol>
4530 <li><tt>eq</tt>: equal</li>
4531 <li><tt>ne</tt>: not equal </li>
4532 <li><tt>ugt</tt>: unsigned greater than</li>
4533 <li><tt>uge</tt>: unsigned greater or equal</li>
4534 <li><tt>ult</tt>: unsigned less than</li>
4535 <li><tt>ule</tt>: unsigned less or equal</li>
4536 <li><tt>sgt</tt>: signed greater than</li>
4537 <li><tt>sge</tt>: signed greater or equal</li>
4538 <li><tt>slt</tt>: signed less than</li>
4539 <li><tt>sle</tt>: signed less or equal</li>
4540</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4541
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4542<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4543 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4544 typed. They must also be identical types.</p>
4545
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4546<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4547<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4548 condition code given as <tt>cond</tt>. The comparison performed always yields
4549 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4550 result, as follows:</p>
4551
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4552<ol>
4553 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4554 <tt>false</tt> otherwise. No sign interpretation is necessary or
4555 performed.</li>
4556
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4557 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4558 <tt>false</tt> otherwise. No sign interpretation is necessary or
4559 performed.</li>
4560
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4561 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4562 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4563
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4564 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4565 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4566 to <tt>op2</tt>.</li>
4567
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4568 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4569 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4570
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4571 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4572 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4573
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4574 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4575 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4576
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4577 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4578 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4579 to <tt>op2</tt>.</li>
4580
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4581 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4582 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4583
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4584 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4585 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4586</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4587
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4588<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4589 values are compared as if they were integers.</p>
4590
4591<p>If the operands are integer vectors, then they are compared element by
4592 element. The result is an <tt>i1</tt> vector with the same number of elements
4593 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4594
4595<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4596<pre>
4597 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4598 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4599 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4600 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4601 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4602 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4603</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4604
4605<p>Note that the code generator does not yet support vector types with
4606 the <tt>icmp</tt> instruction.</p>
4607
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4608</div>
4609
4610<!-- _______________________________________________________________________ -->
4611<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4612</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4613
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4614<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4615
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4616<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4617<pre>
4618 &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 Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4619</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4620
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4621<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4622<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4623 values based on comparison of its operands.</p>
4624
4625<p>If the operands are floating point scalars, then the result type is a boolean
4626(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4627
4628<p>If the operands are floating point vectors, then the result type is a vector
4629 of boolean with the same number of elements as the operands being
4630 compared.</p>
4631
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4632<h5>Arguments:</h5>
4633<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4634 the condition code indicating the kind of comparison to perform. It is not a
4635 value, just a keyword. The possible condition code are:</p>
4636
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4637<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4638 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4639 <li><tt>oeq</tt>: ordered and equal</li>
4640 <li><tt>ogt</tt>: ordered and greater than </li>
4641 <li><tt>oge</tt>: ordered and greater than or equal</li>
4642 <li><tt>olt</tt>: ordered and less than </li>
4643 <li><tt>ole</tt>: ordered and less than or equal</li>
4644 <li><tt>one</tt>: ordered and not equal</li>
4645 <li><tt>ord</tt>: ordered (no nans)</li>
4646 <li><tt>ueq</tt>: unordered or equal</li>
4647 <li><tt>ugt</tt>: unordered or greater than </li>
4648 <li><tt>uge</tt>: unordered or greater than or equal</li>
4649 <li><tt>ult</tt>: unordered or less than </li>
4650 <li><tt>ule</tt>: unordered or less than or equal</li>
4651 <li><tt>une</tt>: unordered or not equal</li>
4652 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4653 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4654</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4655
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4656<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4657 <i>unordered</i> means that either operand may be a QNAN.</p>
4658
4659<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4660 a <a href="#t_floating">floating point</a> type or
4661 a <a href="#t_vector">vector</a> of floating point type. They must have
4662 identical types.</p>
4663
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4664<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4665<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4666 according to the condition code given as <tt>cond</tt>. If the operands are
4667 vectors, then the vectors are compared element by element. Each comparison
4668 performed always yields an <a href="#t_primitive">i1</a> result, as
4669 follows:</p>
4670
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4671<ol>
4672 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4673
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4674 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4675 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4676
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4677 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4678 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4679
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4680 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4681 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4682
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4683 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4684 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4685
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4686 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4687 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4688
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4689 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4690 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4691
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4692 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4693
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4694 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4695 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4696
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4697 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4698 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4699
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4700 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4701 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4702
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4703 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4704 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4705
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4706 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4707 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4708
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4709 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4710 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4711
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4712 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4713
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4714 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4715</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4716
4717<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4718<pre>
4719 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4720 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4721 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4722 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4723</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4724
4725<p>Note that the code generator does not yet support vector types with
4726 the <tt>fcmp</tt> instruction.</p>
4727
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4728</div>
4729
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4730<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4731<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4732 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4733</div>
4734
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4735<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4736
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4737<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4738<pre>
4739 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4740</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4741
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4742<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4743<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4744 SSA graph representing the function.</p>
4745
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4746<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4747<p>The type of the incoming values is specified with the first type field. After
4748 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4749 one pair for each predecessor basic block of the current block. Only values
4750 of <a href="#t_firstclass">first class</a> type may be used as the value
4751 arguments to the PHI node. Only labels may be used as the label
4752 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4753
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4754<p>There must be no non-phi instructions between the start of a basic block and
4755 the PHI instructions: i.e. PHI instructions must be first in a basic
4756 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4757
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4758<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4759 occur on the edge from the corresponding predecessor block to the current
4760 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4761 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]4762
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4763<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4764<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4765 specified by the pair corresponding to the predecessor basic block that
4766 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4767
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4768<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4769<pre>
4770Loop: ; Infinite loop that counts from 0 on up...
4771 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4772 %nextindvar = add i32 %indvar, 1
4773 br label %Loop
4774</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4775
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4776</div>
4777
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4778<!-- _______________________________________________________________________ -->
4779<div class="doc_subsubsection">
4780 <a name="i_select">'<tt>select</tt>' Instruction</a>
4781</div>
4782
4783<div class="doc_text">
4784
4785<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4786<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4787 &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>
4788
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4789 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4790</pre>
4791
4792<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4793<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4794 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4795
4796
4797<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4798<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4799 values indicating the condition, and two values of the
4800 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4801 vectors and the condition is a scalar, then entire vectors are selected, not
4802 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4803
4804<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4805<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4806 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4807
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4808<p>If the condition is a vector of i1, then the value arguments must be vectors
4809 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4810
4811<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4812<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4813 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4814</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4815
4816<p>Note that the code generator does not yet support conditions
4817 with vector type.</p>
4818
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4819</div>
4820
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4821<!-- _______________________________________________________________________ -->
4822<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4823 <a name="i_call">'<tt>call</tt>' Instruction</a>
4824</div>
4825
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4826<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4827
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4828<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4829<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4830 &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 Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4831</pre>
4832
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4833<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4834<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4835
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4836<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4837<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4838
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4839<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4840 <li>The optional "tail" marker indicates whether the callee function accesses
4841 any allocas or varargs in the caller. If the "tail" marker is present,
4842 the function call is eligible for tail call optimization. Note that calls
4843 may be marked "tail" even if they do not occur before
4844 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4845
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4846 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4847 convention</a> the call should use. If none is specified, the call
4848 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4849
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4850 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4851 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4852 '<tt>inreg</tt>' attributes are valid here.</li>
4853
4854 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4855 type of the return value. Functions that return no value are marked
4856 <tt><a href="#t_void">void</a></tt>.</li>
4857
4858 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4859 being invoked. The argument types must match the types implied by this
4860 signature. This type can be omitted if the function is not varargs and if
4861 the function type does not return a pointer to a function.</li>
4862
4863 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4864 be invoked. In most cases, this is a direct function invocation, but
4865 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4866 to function value.</li>
4867
4868 <li>'<tt>function args</tt>': argument list whose types match the function
4869 signature argument types. All arguments must be of
4870 <a href="#t_firstclass">first class</a> type. If the function signature
4871 indicates the function accepts a variable number of arguments, the extra
4872 arguments can be specified.</li>
4873
4874 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4875 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4876 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4877</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4878
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4879<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4880<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4881 a specified function, with its incoming arguments bound to the specified
4882 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4883 function, control flow continues with the instruction after the function
4884 call, and the return value of the function is bound to the result
4885 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4886
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4887<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4888<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4889 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4890 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4891 %X = tail call i32 @foo() <i>; yields i32</i>
4892 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4893 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4894
4895 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4896 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4897 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4898 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4899 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4900 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4901</pre>
4902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4903</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4904
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4905<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4906<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4907 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4908</div>
4909
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4910<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4911
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4912<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4913<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4914 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4915</pre>
4916
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4917<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4918<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919 the "variable argument" area of a function call. It is used to implement the
4920 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4921
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4922<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4923<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4924 argument. It returns a value of the specified argument type and increments
4925 the <tt>va_list</tt> to point to the next argument. The actual type
4926 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4927
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4928<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4929<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4930 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4931 to the next argument. For more information, see the variable argument
4932 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4933
4934<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4935 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4936 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4937
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4938<p><tt>va_arg</tt> is an LLVM instruction instead of
4939 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4940 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4941
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4942<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4943<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4944
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4945<p>Note that the code generator does not yet fully support va_arg on many
4946 targets. Also, it does not currently support va_arg with aggregate types on
4947 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]4948
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4949</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4950
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4951<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4952<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4953<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4954
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4955<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4956
4957<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4958 well known names and semantics and are required to follow certain
4959 restrictions. Overall, these intrinsics represent an extension mechanism for
4960 the LLVM language that does not require changing all of the transformations
4961 in LLVM when adding to the language (or the bitcode reader/writer, the
4962 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4963
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4964<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4965 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4966 begin with this prefix. Intrinsic functions must always be external
4967 functions: you cannot define the body of intrinsic functions. Intrinsic
4968 functions may only be used in call or invoke instructions: it is illegal to
4969 take the address of an intrinsic function. Additionally, because intrinsic
4970 functions are part of the LLVM language, it is required if any are added that
4971 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4972
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4973<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4974 family of functions that perform the same operation but on different data
4975 types. Because LLVM can represent over 8 million different integer types,
4976 overloading is used commonly to allow an intrinsic function to operate on any
4977 integer type. One or more of the argument types or the result type can be
4978 overloaded to accept any integer type. Argument types may also be defined as
4979 exactly matching a previous argument's type or the result type. This allows
4980 an intrinsic function which accepts multiple arguments, but needs all of them
4981 to be of the same type, to only be overloaded with respect to a single
4982 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4983
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4984<p>Overloaded intrinsics will have the names of its overloaded argument types
4985 encoded into its function name, each preceded by a period. Only those types
4986 which are overloaded result in a name suffix. Arguments whose type is matched
4987 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4988 can take an integer of any width and returns an integer of exactly the same
4989 integer width. This leads to a family of functions such as
4990 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4991 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4992 suffix is required. Because the argument's type is matched against the return
4993 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4994
4995<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4996 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4997
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4998</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4999
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5000<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5001<div class="doc_subsection">
5002 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5003</div>
5004
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5005<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5006
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5007<p>Variable argument support is defined in LLVM with
5008 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5009 intrinsic functions. These functions are related to the similarly named
5010 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5011
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5012<p>All of these functions operate on arguments that use a target-specific value
5013 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5014 not define what this type is, so all transformations should be prepared to
5015 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5016
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5017<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5018 instruction and the variable argument handling intrinsic functions are
5019 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5020
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5021<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5022<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5023define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5024 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5025 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5026 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5027 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5028
5029 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5030 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5031
5032 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5033 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5034 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5035 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5036 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5037
5038 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5039 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5040 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5041}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5042
5043declare void @llvm.va_start(i8*)
5044declare void @llvm.va_copy(i8*, i8*)
5045declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5046</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5047</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5048
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5049</div>
5050
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5051<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5052<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5053 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5054</div>
5055
5056
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5057<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5058
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5059<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5060<pre>
5061 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5062</pre>
5063
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5064<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5065<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5066 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5067
5068<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5069<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5070
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5071<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5072<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073 macro available in C. In a target-dependent way, it initializes
5074 the <tt>va_list</tt> element to which the argument points, so that the next
5075 call to <tt>va_arg</tt> will produce the first variable argument passed to
5076 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5077 need to know the last argument of the function as the compiler can figure
5078 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5079
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5080</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5081
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5082<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5083<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5084 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5085</div>
5086
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5087<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5088
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5089<h5>Syntax:</h5>
5090<pre>
5091 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5092</pre>
5093
5094<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5095<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5096 which has been initialized previously
5097 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5098 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5099
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5100<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5101<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5102
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5103<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5104<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5105 macro available in C. In a target-dependent way, it destroys
5106 the <tt>va_list</tt> element to which the argument points. Calls
5107 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5108 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5109 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5110
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5111</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5112
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5113<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5114<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5115 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5116</div>
5117
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5118<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5119
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5120<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5121<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5122 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5123</pre>
5124
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5125<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5126<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5127 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5128
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5129<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5130<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5131 The second argument is a pointer to a <tt>va_list</tt> element to copy
5132 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5133
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5134<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5135<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5136 macro available in C. In a target-dependent way, it copies the
5137 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5138 element. This intrinsic is necessary because
5139 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5140 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5141
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5142</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5143
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5144<!-- ======================================================================= -->
5145<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5146 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5147</div>
5148
5149<div class="doc_text">
5150
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5151<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5152Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5153intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5154roots on the stack</a>, as well as garbage collector implementations that
5155require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5156barriers. Front-ends for type-safe garbage collected languages should generate
5157these intrinsics to make use of the LLVM garbage collectors. For more details,
5158see <a href="GarbageCollection.html">Accurate Garbage Collection with
5159LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5160
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5161<p>The garbage collection intrinsics only operate on objects in the generic
5162 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5163
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5164</div>
5165
5166<!-- _______________________________________________________________________ -->
5167<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5168 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5169</div>
5170
5171<div class="doc_text">
5172
5173<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5174<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5175 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5176</pre>
5177
5178<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5179<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5180 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5181
5182<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5183<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5184 root pointer. The second pointer (which must be either a constant or a
5185 global value address) contains the meta-data to be associated with the
5186 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5187
5188<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5189<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5190 location. At compile-time, the code generator generates information to allow
5191 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5192 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5193 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5194
5195</div>
5196
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5197<!-- _______________________________________________________________________ -->
5198<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5199 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5200</div>
5201
5202<div class="doc_text">
5203
5204<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5205<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5206 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5207</pre>
5208
5209<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5210<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5211 locations, allowing garbage collector implementations that require read
5212 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5213
5214<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5215<p>The second argument is the address to read from, which should be an address
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5216 allocated from the garbage collector. The first object is a pointer to the
5217 start of the referenced object, if needed by the language runtime (otherwise
5218 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5219
5220<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5221<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5222 instruction, but may be replaced with substantially more complex code by the
5223 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5224 may only be used in a function which <a href="#gc">specifies a GC
5225 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5226
5227</div>
5228
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5229<!-- _______________________________________________________________________ -->
5230<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5231 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5232</div>
5233
5234<div class="doc_text">
5235
5236<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5237<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5238 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5239</pre>
5240
5241<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5242<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5243 locations, allowing garbage collector implementations that require write
5244 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5245
5246<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5247<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5248 object to store it to, and the third is the address of the field of Obj to
5249 store to. If the runtime does not require a pointer to the object, Obj may
5250 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5251
5252<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5253<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5254 instruction, but may be replaced with substantially more complex code by the
5255 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5256 may only be used in a function which <a href="#gc">specifies a GC
5257 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5258
5259</div>
5260
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5261<!-- ======================================================================= -->
5262<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5263 <a name="int_codegen">Code Generator Intrinsics</a>
5264</div>
5265
5266<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5267
5268<p>These intrinsics are provided by LLVM to expose special features that may
5269 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5270
5271</div>
5272
5273<!-- _______________________________________________________________________ -->
5274<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5275 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5276</div>
5277
5278<div class="doc_text">
5279
5280<h5>Syntax:</h5>
5281<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5282 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5283</pre>
5284
5285<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5286<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5287 target-specific value indicating the return address of the current function
5288 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5289
5290<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5291<p>The argument to this intrinsic indicates which function to return the address
5292 for. Zero indicates the calling function, one indicates its caller, etc.
5293 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5294
5295<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5296<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5297 indicating the return address of the specified call frame, or zero if it
5298 cannot be identified. The value returned by this intrinsic is likely to be
5299 incorrect or 0 for arguments other than zero, so it should only be used for
5300 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5301
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5302<p>Note that calling this intrinsic does not prevent function inlining or other
5303 aggressive transformations, so the value returned may not be that of the
5304 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5305
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5306</div>
5307
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5308<!-- _______________________________________________________________________ -->
5309<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5310 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5311</div>
5312
5313<div class="doc_text">
5314
5315<h5>Syntax:</h5>
5316<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5317 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5318</pre>
5319
5320<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5321<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5322 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5323
5324<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5325<p>The argument to this intrinsic indicates which function to return the frame
5326 pointer for. Zero indicates the calling function, one indicates its caller,
5327 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5328
5329<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5330<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5331 indicating the frame address of the specified call frame, or zero if it
5332 cannot be identified. The value returned by this intrinsic is likely to be
5333 incorrect or 0 for arguments other than zero, so it should only be used for
5334 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5335
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5336<p>Note that calling this intrinsic does not prevent function inlining or other
5337 aggressive transformations, so the value returned may not be that of the
5338 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5339
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5340</div>
5341
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5342<!-- _______________________________________________________________________ -->
5343<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5344 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5345</div>
5346
5347<div class="doc_text">
5348
5349<h5>Syntax:</h5>
5350<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5351 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5352</pre>
5353
5354<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5355<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5356 of the function stack, for use
5357 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5358 useful for implementing language features like scoped automatic variable
5359 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5360
5361<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5362<p>This intrinsic returns a opaque pointer value that can be passed
5363 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5364 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5365 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5366 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5367 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5368 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5369
5370</div>
5371
5372<!-- _______________________________________________________________________ -->
5373<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5374 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5375</div>
5376
5377<div class="doc_text">
5378
5379<h5>Syntax:</h5>
5380<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5381 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5382</pre>
5383
5384<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5385<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5386 the function stack to the state it was in when the
5387 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5388 executed. This is useful for implementing language features like scoped
5389 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5390
5391<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5392<p>See the description
5393 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5394
5395</div>
5396
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5397<!-- _______________________________________________________________________ -->
5398<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5399 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5400</div>
5401
5402<div class="doc_text">
5403
5404<h5>Syntax:</h5>
5405<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5406 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5407</pre>
5408
5409<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5410<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5411 insert a prefetch instruction if supported; otherwise, it is a noop.
5412 Prefetches have no effect on the behavior of the program but can change its
5413 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5414
5415<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5416<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5417 specifier determining if the fetch should be for a read (0) or write (1),
5418 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5419 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5420 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5421
5422<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5423<p>This intrinsic does not modify the behavior of the program. In particular,
5424 prefetches cannot trap and do not produce a value. On targets that support
5425 this intrinsic, the prefetch can provide hints to the processor cache for
5426 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5427
5428</div>
5429
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5430<!-- _______________________________________________________________________ -->
5431<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5432 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5433</div>
5434
5435<div class="doc_text">
5436
5437<h5>Syntax:</h5>
5438<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5439 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5440</pre>
5441
5442<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5443<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5444 Counter (PC) in a region of code to simulators and other tools. The method
5445 is target specific, but it is expected that the marker will use exported
5446 symbols to transmit the PC of the marker. The marker makes no guarantees
5447 that it will remain with any specific instruction after optimizations. It is
5448 possible that the presence of a marker will inhibit optimizations. The
5449 intended use is to be inserted after optimizations to allow correlations of
5450 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5451
5452<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5453<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5454
5455<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5456<p>This intrinsic does not modify the behavior of the program. Backends that do
5457 not support this intrinisic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5458
5459</div>
5460
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5461<!-- _______________________________________________________________________ -->
5462<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5463 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5464</div>
5465
5466<div class="doc_text">
5467
5468<h5>Syntax:</h5>
5469<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5470 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5471</pre>
5472
5473<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5474<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5475 counter register (or similar low latency, high accuracy clocks) on those
5476 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5477 should map to RPCC. As the backing counters overflow quickly (on the order
5478 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5479
5480<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5481<p>When directly supported, reading the cycle counter should not modify any
5482 memory. Implementations are allowed to either return a application specific
5483 value or a system wide value. On backends without support, this is lowered
5484 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5485
5486</div>
5487
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5488<!-- ======================================================================= -->
5489<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5490 <a name="int_libc">Standard C Library Intrinsics</a>
5491</div>
5492
5493<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5494
5495<p>LLVM provides intrinsics for a few important standard C library functions.
5496 These intrinsics allow source-language front-ends to pass information about
5497 the alignment of the pointer arguments to the code generator, providing
5498 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5499
5500</div>
5501
5502<!-- _______________________________________________________________________ -->
5503<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5504 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5505</div>
5506
5507<div class="doc_text">
5508
5509<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5510<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5511 integer bit width. Not all targets support all bit widths however.</p>
5512
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5513<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5514 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5515 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5516 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5517 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5518 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5519 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5520 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5521 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5522</pre>
5523
5524<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5525<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5526 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5527
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5528<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5529 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5530
5531<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5532<p>The first argument is a pointer to the destination, the second is a pointer
5533 to the source. The third argument is an integer argument specifying the
5534 number of bytes to copy, and the fourth argument is the alignment of the
5535 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5536
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5538 then the caller guarantees that both the source and destination pointers are
5539 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5540
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5541<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5542<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5543 source location to the destination location, which are not allowed to
5544 overlap. It copies "len" bytes of memory over. If the argument is known to
5545 be aligned to some boundary, this can be specified as the fourth argument,
5546 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5547
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5548</div>
5549
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5550<!-- _______________________________________________________________________ -->
5551<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5552 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5553</div>
5554
5555<div class="doc_text">
5556
5557<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5558<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5559 width. Not all targets support all bit widths however.</p>
5560
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5561<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5562 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5563 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5564 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5565 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5566 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5567 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5568 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5569 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5570</pre>
5571
5572<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5573<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5574 source location to the destination location. It is similar to the
5575 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5576 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5577
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5578<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5579 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5580
5581<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5582<p>The first argument is a pointer to the destination, the second is a pointer
5583 to the source. The third argument is an integer argument specifying the
5584 number of bytes to copy, and the fourth argument is the alignment of the
5585 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5586
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5587<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5588 then the caller guarantees that the source and destination pointers are
5589 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5590
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5591<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5592<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5593 source location to the destination location, which may overlap. It copies
5594 "len" bytes of memory over. If the argument is known to be aligned to some
5595 boundary, this can be specified as the fourth argument, otherwise it should
5596 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5597
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5598</div>
5599
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5600<!-- _______________________________________________________________________ -->
5601<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5602 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5603</div>
5604
5605<div class="doc_text">
5606
5607<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5608<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5609 width. Not all targets support all bit widths however.</p>
5610
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5611<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5612 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5613 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5614 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5615 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5616 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5617 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5618 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5619 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5620</pre>
5621
5622<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5623<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5624 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5625
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5626<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5627 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5628
5629<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5630<p>The first argument is a pointer to the destination to fill, the second is the
5631 byte value to fill it with, the third argument is an integer argument
5632 specifying the number of bytes to fill, and the fourth argument is the known
5633 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5634
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5635<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5636 then the caller guarantees that the destination pointer is aligned to that
5637 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5638
5639<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5640<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5641 at the destination location. If the argument is known to be aligned to some
5642 boundary, this can be specified as the fourth argument, otherwise it should
5643 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5644
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5645</div>
5646
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5647<!-- _______________________________________________________________________ -->
5648<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5649 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5650</div>
5651
5652<div class="doc_text">
5653
5654<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5655<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5656 floating point or vector of floating point type. Not all targets support all
5657 types however.</p>
5658
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5659<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5660 declare float @llvm.sqrt.f32(float %Val)
5661 declare double @llvm.sqrt.f64(double %Val)
5662 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5663 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5664 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5665</pre>
5666
5667<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5668<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5669 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5670 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5671 behavior for negative numbers other than -0.0 (which allows for better
5672 optimization, because there is no need to worry about errno being
5673 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5674
5675<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5676<p>The argument and return value are floating point numbers of the same
5677 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5678
5679<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5680<p>This function returns the sqrt of the specified operand if it is a
5681 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5682
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5683</div>
5684
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5685<!-- _______________________________________________________________________ -->
5686<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5687 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5688</div>
5689
5690<div class="doc_text">
5691
5692<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5693<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5694 floating point or vector of floating point type. Not all targets support all
5695 types however.</p>
5696
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5697<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5698 declare float @llvm.powi.f32(float %Val, i32 %power)
5699 declare double @llvm.powi.f64(double %Val, i32 %power)
5700 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5701 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5702 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5703</pre>
5704
5705<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5706<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5707 specified (positive or negative) power. The order of evaluation of
5708 multiplications is not defined. When a vector of floating point type is
5709 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5710
5711<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5712<p>The second argument is an integer power, and the first is a value to raise to
5713 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5714
5715<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5716<p>This function returns the first value raised to the second power with an
5717 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5718
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5719</div>
5720
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5721<!-- _______________________________________________________________________ -->
5722<div class="doc_subsubsection">
5723 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5724</div>
5725
5726<div class="doc_text">
5727
5728<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5729<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5730 floating point or vector of floating point type. Not all targets support all
5731 types however.</p>
5732
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5733<pre>
5734 declare float @llvm.sin.f32(float %Val)
5735 declare double @llvm.sin.f64(double %Val)
5736 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5737 declare fp128 @llvm.sin.f128(fp128 %Val)
5738 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5739</pre>
5740
5741<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5742<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5743
5744<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5745<p>The argument and return value are floating point numbers of the same
5746 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5747
5748<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5749<p>This function returns the sine of the specified operand, returning the same
5750 values as the libm <tt>sin</tt> functions would, and handles error conditions
5751 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5752
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5753</div>
5754
5755<!-- _______________________________________________________________________ -->
5756<div class="doc_subsubsection">
5757 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5758</div>
5759
5760<div class="doc_text">
5761
5762<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5763<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5764 floating point or vector of floating point type. Not all targets support all
5765 types however.</p>
5766
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5767<pre>
5768 declare float @llvm.cos.f32(float %Val)
5769 declare double @llvm.cos.f64(double %Val)
5770 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5771 declare fp128 @llvm.cos.f128(fp128 %Val)
5772 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5773</pre>
5774
5775<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5776<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5777
5778<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5779<p>The argument and return value are floating point numbers of the same
5780 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5781
5782<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5783<p>This function returns the cosine of the specified operand, returning the same
5784 values as the libm <tt>cos</tt> functions would, and handles error conditions
5785 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5786
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5787</div>
5788
5789<!-- _______________________________________________________________________ -->
5790<div class="doc_subsubsection">
5791 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5792</div>
5793
5794<div class="doc_text">
5795
5796<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5797<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5798 floating point or vector of floating point type. Not all targets support all
5799 types however.</p>
5800
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5801<pre>
5802 declare float @llvm.pow.f32(float %Val, float %Power)
5803 declare double @llvm.pow.f64(double %Val, double %Power)
5804 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5805 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5806 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5807</pre>
5808
5809<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5810<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5811 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5812
5813<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5814<p>The second argument is a floating point power, and the first is a value to
5815 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5816
5817<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5818<p>This function returns the first value raised to the second power, returning
5819 the same values as the libm <tt>pow</tt> functions would, and handles error
5820 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5821
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5822</div>
5823
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5824<!-- ======================================================================= -->
5825<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5826 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5827</div>
5828
5829<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5830
5831<p>LLVM provides intrinsics for a few important bit manipulation operations.
5832 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5833
5834</div>
5835
5836<!-- _______________________________________________________________________ -->
5837<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5838 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5839</div>
5840
5841<div class="doc_text">
5842
5843<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5844<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5845 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5846
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5847<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5848 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5849 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5850 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5851</pre>
5852
5853<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5854<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5855 values with an even number of bytes (positive multiple of 16 bits). These
5856 are useful for performing operations on data that is not in the target's
5857 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5858
5859<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5860<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5861 and low byte of the input i16 swapped. Similarly,
5862 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5863 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5864 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5865 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5866 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5867 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5868
5869</div>
5870
5871<!-- _______________________________________________________________________ -->
5872<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5873 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5874</div>
5875
5876<div class="doc_text">
5877
5878<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5879<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5880 width. Not all targets support all bit widths however.</p>
5881
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5882<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5883 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5884 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5885 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5886 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5887 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5888</pre>
5889
5890<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5891<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5892 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5893
5894<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5895<p>The only argument is the value to be counted. The argument may be of any
5896 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5897
5898<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5899<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5900
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5901</div>
5902
5903<!-- _______________________________________________________________________ -->
5904<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5905 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5906</div>
5907
5908<div class="doc_text">
5909
5910<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5911<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5912 integer bit width. Not all targets support all bit widths however.</p>
5913
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5914<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5915 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5916 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5917 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5918 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5919 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5920</pre>
5921
5922<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5923<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5924 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5925
5926<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5927<p>The only argument is the value to be counted. The argument may be of any
5928 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5929
5930<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5931<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5932 zeros in a variable. If the src == 0 then the result is the size in bits of
5933 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5934
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5935</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5936
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5937<!-- _______________________________________________________________________ -->
5938<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5939 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5940</div>
5941
5942<div class="doc_text">
5943
5944<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5945<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5946 integer bit width. Not all targets support all bit widths however.</p>
5947
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5948<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5949 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5950 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5951 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5952 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5953 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5954</pre>
5955
5956<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5957<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5958 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5959
5960<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5961<p>The only argument is the value to be counted. The argument may be of any
5962 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5963
5964<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5965<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5966 zeros in a variable. If the src == 0 then the result is the size in bits of
5967 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5968
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5969</div>
5970
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5971<!-- ======================================================================= -->
5972<div class="doc_subsection">
5973 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5974</div>
5975
5976<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5977
5978<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5979
5980</div>
5981
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5982<!-- _______________________________________________________________________ -->
5983<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5984 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5985</div>
5986
5987<div class="doc_text">
5988
5989<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5990<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5991 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5992
5993<pre>
5994 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5995 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5996 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5997</pre>
5998
5999<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6000<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6001 a signed addition of the two arguments, and indicate whether an overflow
6002 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6003
6004<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6005<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6006 be of integer types of any bit width, but they must have the same bit
6007 width. The second element of the result structure must be of
6008 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6009 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6010
6011<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6012<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6013 a signed addition of the two variables. They return a structure &mdash; the
6014 first element of which is the signed summation, and the second element of
6015 which is a bit specifying if the signed summation resulted in an
6016 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6017
6018<h5>Examples:</h5>
6019<pre>
6020 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6021 %sum = extractvalue {i32, i1} %res, 0
6022 %obit = extractvalue {i32, i1} %res, 1
6023 br i1 %obit, label %overflow, label %normal
6024</pre>
6025
6026</div>
6027
6028<!-- _______________________________________________________________________ -->
6029<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6030 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6031</div>
6032
6033<div class="doc_text">
6034
6035<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6036<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6037 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6038
6039<pre>
6040 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6041 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6042 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6043</pre>
6044
6045<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6046<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6047 an unsigned addition of the two arguments, and indicate whether a carry
6048 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6049
6050<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6051<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6052 be of integer types of any bit width, but they must have the same bit
6053 width. The second element of the result structure must be of
6054 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6055 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6056
6057<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6058<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6059 an unsigned addition of the two arguments. They return a structure &mdash;
6060 the first element of which is the sum, and the second element of which is a
6061 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6062
6063<h5>Examples:</h5>
6064<pre>
6065 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6066 %sum = extractvalue {i32, i1} %res, 0
6067 %obit = extractvalue {i32, i1} %res, 1
6068 br i1 %obit, label %carry, label %normal
6069</pre>
6070
6071</div>
6072
6073<!-- _______________________________________________________________________ -->
6074<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6075 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6076</div>
6077
6078<div class="doc_text">
6079
6080<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6081<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6082 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6083
6084<pre>
6085 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6086 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6087 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6088</pre>
6089
6090<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6091<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6092 a signed subtraction of the two arguments, and indicate whether an overflow
6093 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6094
6095<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6096<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6097 be of integer types of any bit width, but they must have the same bit
6098 width. The second element of the result structure must be of
6099 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6100 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6101
6102<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6103<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6104 a signed subtraction of the two arguments. They return a structure &mdash;
6105 the first element of which is the subtraction, and the second element of
6106 which is a bit specifying if the signed subtraction resulted in an
6107 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6108
6109<h5>Examples:</h5>
6110<pre>
6111 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6112 %sum = extractvalue {i32, i1} %res, 0
6113 %obit = extractvalue {i32, i1} %res, 1
6114 br i1 %obit, label %overflow, label %normal
6115</pre>
6116
6117</div>
6118
6119<!-- _______________________________________________________________________ -->
6120<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6121 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6122</div>
6123
6124<div class="doc_text">
6125
6126<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6127<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6128 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6129
6130<pre>
6131 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6132 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6133 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6134</pre>
6135
6136<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6137<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6138 an unsigned subtraction of the two arguments, and indicate whether an
6139 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6140
6141<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6142<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6143 be of integer types of any bit width, but they must have the same bit
6144 width. The second element of the result structure must be of
6145 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6146 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6147
6148<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6149<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6150 an unsigned subtraction of the two arguments. They return a structure &mdash;
6151 the first element of which is the subtraction, and the second element of
6152 which is a bit specifying if the unsigned subtraction resulted in an
6153 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6154
6155<h5>Examples:</h5>
6156<pre>
6157 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6158 %sum = extractvalue {i32, i1} %res, 0
6159 %obit = extractvalue {i32, i1} %res, 1
6160 br i1 %obit, label %overflow, label %normal
6161</pre>
6162
6163</div>
6164
6165<!-- _______________________________________________________________________ -->
6166<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6167 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6168</div>
6169
6170<div class="doc_text">
6171
6172<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6173<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6174 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6175
6176<pre>
6177 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6178 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6179 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6180</pre>
6181
6182<h5>Overview:</h5>
6183
6184<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6185 a signed multiplication of the two arguments, and indicate whether an
6186 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6187
6188<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6189<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6190 be of integer types of any bit width, but they must have the same bit
6191 width. The second element of the result structure must be of
6192 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6193 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6194
6195<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6196<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6197 a signed multiplication of the two arguments. They return a structure &mdash;
6198 the first element of which is the multiplication, and the second element of
6199 which is a bit specifying if the signed multiplication resulted in an
6200 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6201
6202<h5>Examples:</h5>
6203<pre>
6204 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6205 %sum = extractvalue {i32, i1} %res, 0
6206 %obit = extractvalue {i32, i1} %res, 1
6207 br i1 %obit, label %overflow, label %normal
6208</pre>
6209
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6210</div>
6211
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6212<!-- _______________________________________________________________________ -->
6213<div class="doc_subsubsection">
6214 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6215</div>
6216
6217<div class="doc_text">
6218
6219<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6220<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6221 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6222
6223<pre>
6224 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6225 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6226 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6227</pre>
6228
6229<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6230<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6231 a unsigned multiplication of the two arguments, and indicate whether an
6232 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6233
6234<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6235<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236 be of integer types of any bit width, but they must have the same bit
6237 width. The second element of the result structure must be of
6238 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6239 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6240
6241<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6242<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6243 an unsigned multiplication of the two arguments. They return a structure
6244 &mdash; the first element of which is the multiplication, and the second
6245 element of which is a bit specifying if the unsigned multiplication resulted
6246 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6247
6248<h5>Examples:</h5>
6249<pre>
6250 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6251 %sum = extractvalue {i32, i1} %res, 0
6252 %obit = extractvalue {i32, i1} %res, 1
6253 br i1 %obit, label %overflow, label %normal
6254</pre>
6255
6256</div>
6257
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6258<!-- ======================================================================= -->
6259<div class="doc_subsection">
6260 <a name="int_debugger">Debugger Intrinsics</a>
6261</div>
6262
6263<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6264
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6265<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6266 prefix), are described in
6267 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6268 Level Debugging</a> document.</p>
6269
6270</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6271
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6272<!-- ======================================================================= -->
6273<div class="doc_subsection">
6274 <a name="int_eh">Exception Handling Intrinsics</a>
6275</div>
6276
6277<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6278
6279<p>The LLVM exception handling intrinsics (which all start with
6280 <tt>llvm.eh.</tt> prefix), are described in
6281 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6282 Handling</a> document.</p>
6283
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6284</div>
6285
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6286<!-- ======================================================================= -->
6287<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6288 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6289</div>
6290
6291<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6292
6293<p>This intrinsic makes it possible to excise one parameter, marked with
6294 the <tt>nest</tt> attribute, from a function. The result is a callable
6295 function pointer lacking the nest parameter - the caller does not need to
6296 provide a value for it. Instead, the value to use is stored in advance in a
6297 "trampoline", a block of memory usually allocated on the stack, which also
6298 contains code to splice the nest value into the argument list. This is used
6299 to implement the GCC nested function address extension.</p>
6300
6301<p>For example, if the function is
6302 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6303 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6304 follows:</p>
6305
6306<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6307<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6308 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6309 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6310 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6311 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6312</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6313</div>
6314
6315<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6316 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6317
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6318</div>
6319
6320<!-- _______________________________________________________________________ -->
6321<div class="doc_subsubsection">
6322 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6323</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6324
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6325<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6326
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6327<h5>Syntax:</h5>
6328<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6329 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6330</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6331
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6332<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6333<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6334 function pointer suitable for executing it.</p>
6335
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6336<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6337<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6338 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6339 sufficiently aligned block of memory; this memory is written to by the
6340 intrinsic. Note that the size and the alignment are target-specific - LLVM
6341 currently provides no portable way of determining them, so a front-end that
6342 generates this intrinsic needs to have some target-specific knowledge.
6343 The <tt>func</tt> argument must hold a function bitcast to
6344 an <tt>i8*</tt>.</p>
6345
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6346<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6347<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6348 dependent code, turning it into a function. A pointer to this function is
6349 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6350 function pointer type</a> before being called. The new function's signature
6351 is the same as that of <tt>func</tt> with any arguments marked with
6352 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6353 is allowed, and it must be of pointer type. Calling the new function is
6354 equivalent to calling <tt>func</tt> with the same argument list, but
6355 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6356 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6357 by <tt>tramp</tt> is modified, then the effect of any later call to the
6358 returned function pointer is undefined.</p>
6359
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6360</div>
6361
6362<!-- ======================================================================= -->
6363<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6364 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6365</div>
6366
6367<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6368
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6369<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6370 hardware constructs for atomic operations and memory synchronization. This
6371 provides an interface to the hardware, not an interface to the programmer. It
6372 is aimed at a low enough level to allow any programming models or APIs
6373 (Application Programming Interfaces) which need atomic behaviors to map
6374 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6375 hardware provides a "universal IR" for source languages, it also provides a
6376 starting point for developing a "universal" atomic operation and
6377 synchronization IR.</p>
6378
6379<p>These do <em>not</em> form an API such as high-level threading libraries,
6380 software transaction memory systems, atomic primitives, and intrinsic
6381 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6382 application libraries. The hardware interface provided by LLVM should allow
6383 a clean implementation of all of these APIs and parallel programming models.
6384 No one model or paradigm should be selected above others unless the hardware
6385 itself ubiquitously does so.</p>
6386
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6387</div>
6388
6389<!-- _______________________________________________________________________ -->
6390<div class="doc_subsubsection">
6391 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6392</div>
6393<div class="doc_text">
6394<h5>Syntax:</h5>
6395<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6396 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 Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6397</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6398
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6399<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6400<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6401 specific pairs of memory access types.</p>
6402
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6403<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6404<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6405 The first four arguments enables a specific barrier as listed below. The
6406 fith argument specifies that the barrier applies to io or device or uncached
6407 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6408
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6409<ul>
6410 <li><tt>ll</tt>: load-load barrier</li>
6411 <li><tt>ls</tt>: load-store barrier</li>
6412 <li><tt>sl</tt>: store-load barrier</li>
6413 <li><tt>ss</tt>: store-store barrier</li>
6414 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6415</ul>
6416
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6417<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6418<p>This intrinsic causes the system to enforce some ordering constraints upon
6419 the loads and stores of the program. This barrier does not
6420 indicate <em>when</em> any events will occur, it only enforces
6421 an <em>order</em> in which they occur. For any of the specified pairs of load
6422 and store operations (f.ex. load-load, or store-load), all of the first
6423 operations preceding the barrier will complete before any of the second
6424 operations succeeding the barrier begin. Specifically the semantics for each
6425 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6426
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6427<ul>
6428 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6429 after the barrier begins.</li>
6430 <li><tt>ls</tt>: All loads before the barrier must complete before any
6431 store after the barrier begins.</li>
6432 <li><tt>ss</tt>: All stores before the barrier must complete before any
6433 store after the barrier begins.</li>
6434 <li><tt>sl</tt>: All stores before the barrier must complete before any
6435 load after the barrier begins.</li>
6436</ul>
6437
6438<p>These semantics are applied with a logical "and" behavior when more than one
6439 is enabled in a single memory barrier intrinsic.</p>
6440
6441<p>Backends may implement stronger barriers than those requested when they do
6442 not support as fine grained a barrier as requested. Some architectures do
6443 not need all types of barriers and on such architectures, these become
6444 noops.</p>
6445
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6446<h5>Example:</h5>
6447<pre>
6448%ptr = malloc i32
6449 store i32 4, %ptr
6450
6451%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6452 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6453 <i>; guarantee the above finishes</i>
6454 store i32 8, %ptr <i>; before this begins</i>
6455</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6456
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6457</div>
6458
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6459<!-- _______________________________________________________________________ -->
6460<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6461 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6462</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6463
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6464<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6465
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6466<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6467<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6468 any integer bit width and for different address spaces. Not all targets
6469 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6470
6471<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6472 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6473 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6474 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6475 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6476</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6477
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6478<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6479<p>This loads a value in memory and compares it to a given value. If they are
6480 equal, it stores a new value into the memory.</p>
6481
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6482<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6483<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6484 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6485 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6486 this integer type. While any bit width integer may be used, targets may only
6487 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6488
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6489<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6490<p>This entire intrinsic must be executed atomically. It first loads the value
6491 in memory pointed to by <tt>ptr</tt> and compares it with the
6492 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6493 memory. The loaded value is yielded in all cases. This provides the
6494 equivalent of an atomic compare-and-swap operation within the SSA
6495 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6496
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6497<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6498<pre>
6499%ptr = malloc i32
6500 store i32 4, %ptr
6501
6502%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6503%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6504 <i>; yields {i32}:result1 = 4</i>
6505%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6506%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6507
6508%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6509%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6510 <i>; yields {i32}:result2 = 8</i>
6511%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6512
6513%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6514</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6515
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6516</div>
6517
6518<!-- _______________________________________________________________________ -->
6519<div class="doc_subsubsection">
6520 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6521</div>
6522<div class="doc_text">
6523<h5>Syntax:</h5>
6524
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6525<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6526 integer bit width. Not all targets support all bit widths however.</p>
6527
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6528<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6529 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6530 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6531 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6532 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6533</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6534
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6535<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6536<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6537 the value from memory. It then stores the value in <tt>val</tt> in the memory
6538 at <tt>ptr</tt>.</p>
6539
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6540<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6541<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6542 the <tt>val</tt> argument and the result must be integers of the same bit
6543 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6544 integer type. The targets may only lower integer representations they
6545 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6546
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6547<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6548<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6549 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6550 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6551
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6552<h5>Examples:</h5>
6553<pre>
6554%ptr = malloc i32
6555 store i32 4, %ptr
6556
6557%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6558%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6559 <i>; yields {i32}:result1 = 4</i>
6560%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6561%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6562
6563%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6564%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6565 <i>; yields {i32}:result2 = 8</i>
6566
6567%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6568%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6569</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6570
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6571</div>
6572
6573<!-- _______________________________________________________________________ -->
6574<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6575 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6576
6577</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6578
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6579<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6580
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6581<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6582<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6583 any integer bit width. Not all targets support all bit widths however.</p>
6584
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6585<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6586 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6587 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6588 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6589 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6590</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6591
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6592<h5>Overview:</h5>
6593<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6594 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6595
6596<h5>Arguments:</h5>
6597<p>The intrinsic takes two arguments, the first a pointer to an integer value
6598 and the second an integer value. The result is also an integer value. These
6599 integer types can have any bit width, but they must all have the same bit
6600 width. The targets may only lower integer representations they support.</p>
6601
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6602<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6603<p>This intrinsic does a series of operations atomically. It first loads the
6604 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6605 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6606
6607<h5>Examples:</h5>
6608<pre>
6609%ptr = malloc i32
6610 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6611%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6612 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6613%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6614 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6615%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6616 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6617%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6618</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6619
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6620</div>
6621
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6622<!-- _______________________________________________________________________ -->
6623<div class="doc_subsubsection">
6624 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6625
6626</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6627
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6628<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6629
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6630<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6631<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6632 any integer bit width and for different address spaces. Not all targets
6633 support all bit widths however.</p>
6634
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6635<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6636 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6637 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6638 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6639 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6640</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6641
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6642<h5>Overview:</h5>
6643<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6644 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6645
6646<h5>Arguments:</h5>
6647<p>The intrinsic takes two arguments, the first a pointer to an integer value
6648 and the second an integer value. The result is also an integer value. These
6649 integer types can have any bit width, but they must all have the same bit
6650 width. The targets may only lower integer representations they support.</p>
6651
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6652<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6653<p>This intrinsic does a series of operations atomically. It first loads the
6654 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6655 result to <tt>ptr</tt>. It yields the original value stored
6656 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6657
6658<h5>Examples:</h5>
6659<pre>
6660%ptr = malloc i32
6661 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6662%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6663 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6664%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6665 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6666%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6667 <i>; yields {i32}:result3 = 2</i>
6668%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6669</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6670
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6671</div>
6672
6673<!-- _______________________________________________________________________ -->
6674<div class="doc_subsubsection">
6675 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6676 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6677 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6678 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6679</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6680
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6681<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6682
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6683<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6684<p>These are overloaded intrinsics. You can
6685 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6686 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6687 bit width and for different address spaces. Not all targets support all bit
6688 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6689
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6690<pre>
6691 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6692 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6693 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6694 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6695</pre>
6696
6697<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6698 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6699 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6700 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6701 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6702</pre>
6703
6704<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6705 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6706 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6707 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6708 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6709</pre>
6710
6711<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6712 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6713 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6714 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6715 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6716</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6717
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6718<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6719<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6720 the value stored in memory at <tt>ptr</tt>. It yields the original value
6721 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6722
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6723<h5>Arguments:</h5>
6724<p>These intrinsics take two arguments, the first a pointer to an integer value
6725 and the second an integer value. The result is also an integer value. These
6726 integer types can have any bit width, but they must all have the same bit
6727 width. The targets may only lower integer representations they support.</p>
6728
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6729<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6730<p>These intrinsics does a series of operations atomically. They first load the
6731 value stored at <tt>ptr</tt>. They then do the bitwise
6732 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6733 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6734
6735<h5>Examples:</h5>
6736<pre>
6737%ptr = malloc i32
6738 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6739%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6740 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6741%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6742 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6743%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6744 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6745%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6746 <i>; yields {i32}:result3 = FF</i>
6747%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6748</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6749
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6750</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6751
6752<!-- _______________________________________________________________________ -->
6753<div class="doc_subsubsection">
6754 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6755 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6756 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6757 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6758</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6759
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6760<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6761
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6762<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6763<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6764 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6765 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6766 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6767
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6768<pre>
6769 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6770 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6771 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6772 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6773</pre>
6774
6775<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6777 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6778 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6779 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6780</pre>
6781
6782<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6783 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6784 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6785 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6786 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6787</pre>
6788
6789<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6790 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6791 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6792 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6793 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6794</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6795
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6796<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6797<p>These intrinsics takes the signed or unsigned minimum or maximum of
6798 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6799 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6800
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6801<h5>Arguments:</h5>
6802<p>These intrinsics take two arguments, the first a pointer to an integer value
6803 and the second an integer value. The result is also an integer value. These
6804 integer types can have any bit width, but they must all have the same bit
6805 width. The targets may only lower integer representations they support.</p>
6806
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6807<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6808<p>These intrinsics does a series of operations atomically. They first load the
6809 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6810 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6811 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6812
6813<h5>Examples:</h5>
6814<pre>
6815%ptr = malloc i32
6816 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6817%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6818 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6819%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6820 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6821%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6822 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6823%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6824 <i>; yields {i32}:result3 = 8</i>
6825%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6826</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6827
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6828</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6829
6830<!-- ======================================================================= -->
6831<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6832 <a name="int_general">General Intrinsics</a>
6833</div>
6834
6835<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6836
6837<p>This class of intrinsics is designed to be generic and has no specific
6838 purpose.</p>
6839
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6840</div>
6841
6842<!-- _______________________________________________________________________ -->
6843<div class="doc_subsubsection">
6844 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6845</div>
6846
6847<div class="doc_text">
6848
6849<h5>Syntax:</h5>
6850<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6851 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6852</pre>
6853
6854<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6855<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6856
6857<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6858<p>The first argument is a pointer to a value, the second is a pointer to a
6859 global string, the third is a pointer to a global string which is the source
6860 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6861
6862<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6863<p>This intrinsic allows annotation of local variables with arbitrary strings.
6864 This can be useful for special purpose optimizations that want to look for
6865 these annotations. These have no other defined use, they are ignored by code
6866 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6867
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6868</div>
6869
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6870<!-- _______________________________________________________________________ -->
6871<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6872 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6873</div>
6874
6875<div class="doc_text">
6876
6877<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6879 any integer bit width.</p>
6880
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6881<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6882 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6883 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6884 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6885 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6886 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6887</pre>
6888
6889<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6890<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6891
6892<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6893<p>The first argument is an integer value (result of some expression), the
6894 second is a pointer to a global string, the third is a pointer to a global
6895 string which is the source file name, and the last argument is the line
6896 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6897
6898<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6899<p>This intrinsic allows annotations to be put on arbitrary expressions with
6900 arbitrary strings. This can be useful for special purpose optimizations that
6901 want to look for these annotations. These have no other defined use, they
6902 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6903
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6904</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6905
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6906<!-- _______________________________________________________________________ -->
6907<div class="doc_subsubsection">
6908 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6909</div>
6910
6911<div class="doc_text">
6912
6913<h5>Syntax:</h5>
6914<pre>
6915 declare void @llvm.trap()
6916</pre>
6917
6918<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6919<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6920
6921<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6922<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6923
6924<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6925<p>This intrinsics is lowered to the target dependent trap instruction. If the
6926 target does not have a trap instruction, this intrinsic will be lowered to
6927 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6928
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6929</div>
6930
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6931<!-- _______________________________________________________________________ -->
6932<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6933 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6934</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6935
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6936<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6937
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6938<h5>Syntax:</h5>
6939<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6940 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6941</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6942
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6943<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6944<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6945 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6946 ensure that it is placed on the stack before local variables.</p>
6947
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6948<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6949<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6950 arguments. The first argument is the value loaded from the stack
6951 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6952 that has enough space to hold the value of the guard.</p>
6953
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6954<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6955<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6956 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6957 stack. This is to ensure that if a local variable on the stack is
6958 overwritten, it will destroy the value of the guard. When the function exits,
6959 the guard on the stack is checked against the original guard. If they're
6960 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6961 function.</p>
6962
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6963</div>
6964
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6965<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6966<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6967<address>
6968 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6969 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6970 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6971 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6972
6973 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6974 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6975 Last modified: $Date$
6976</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6977
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6978</body>
6979</html>