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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 419e223f5d1f24ab153195386b7f2bcc7bfaa5f6 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]34 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]46 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]47 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]48 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]49 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]50 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]51 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]52 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]53 </ol>
54 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]55 <li><a href="#typesystem">Type System</a>
56 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]57 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]58 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]59 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]60 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_floating">Floating Point Types</a></li>
62 <li><a href="#t_void">Void Type</a></li>
63 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]64 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]65 </ol>
66 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#t_derived">Derived Types</a>
68 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]69 <li><a href="#t_aggregate">Aggregate Types</a>
70 <ol>
71 <li><a href="#t_array">Array Type</a></li>
72 <li><a href="#t_struct">Structure Type</a></li>
73 <li><a href="#t_pstruct">Packed Structure Type</a></li>
74 <li><a href="#t_union">Union Type</a></li>
75 <li><a href="#t_vector">Vector Type</a></li>
76 </ol>
77 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#t_function">Function Type</a></li>
79 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]80 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]81 </ol>
82 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]83 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]86 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]87 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]88 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]89 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
91 <li><a href="#undefvalues">Undefined Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]92 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]94 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]95 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]96 <li><a href="#othervalues">Other Values</a>
97 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]98 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]99 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]102 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
103 <ol>
104 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]105 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
106 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]107 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
108 Global Variable</a></li>
109 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
110 Global Variable</a></li>
111 </ol>
112 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]113 <li><a href="#instref">Instruction Reference</a>
114 <ol>
115 <li><a href="#terminators">Terminator Instructions</a>
116 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]117 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
118 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]119 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]120 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]123 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 </ol>
125 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]126 <li><a href="#binaryops">Binary Operations</a>
127 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]128 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]129 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]134 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
135 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
136 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]137 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
138 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
139 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 </ol>
141 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]142 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
143 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]144 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
145 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
146 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]147 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]150 </ol>
151 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]152 <li><a href="#vectorops">Vector Operations</a>
153 <ol>
154 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
155 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
156 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]157 </ol>
158 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]159 <li><a href="#aggregateops">Aggregate Operations</a>
160 <ol>
161 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
162 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
163 </ol>
164 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]165 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]166 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]167 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]168 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
169 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
170 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]171 </ol>
172 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]173 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]174 <ol>
175 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
176 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
178 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
179 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]180 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
182 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
183 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]184 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
185 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]186 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]187 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]188 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]189 <li><a href="#otherops">Other Operations</a>
190 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]191 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
192 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]193 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]194 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]196 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]197 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]198 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]199 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]200 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]201 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]202 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
204 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]205 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
206 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
207 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]210 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
211 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
213 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
214 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]215 </ol>
216 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]217 <li><a href="#int_codegen">Code Generator Intrinsics</a>
218 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]219 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
220 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
221 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
222 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
223 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
224 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
225 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]226 </ol>
227 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]228 <li><a href="#int_libc">Standard C Library Intrinsics</a>
229 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]230 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
232 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]235 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]238 </ol>
239 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]240 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]241 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]242 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]243 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
244 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
245 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]246 </ol>
247 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]248 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
249 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]250 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
251 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
252 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
253 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
254 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]255 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]256 </ol>
257 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]258 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
259 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]260 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
261 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]262 </ol>
263 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]264 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]265 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]266 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]267 <ol>
268 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]269 </ol>
270 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]271 <li><a href="#int_atomics">Atomic intrinsics</a>
272 <ol>
273 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
274 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
275 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
276 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
277 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
278 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
279 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
280 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
281 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
282 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
283 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
284 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
285 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
286 </ol>
287 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]288 <li><a href="#int_memorymarkers">Memory Use Markers</a>
289 <ol>
290 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
291 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
292 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
293 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
294 </ol>
295 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]296 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]297 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]298 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]299 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]300 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]301 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]302 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]303 '<tt>llvm.trap</tt>' Intrinsic</a></li>
304 <li><a href="#int_stackprotector">
305 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]306 <li><a href="#int_objectsize">
307 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]308 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]309 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]310 </ol>
311 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]312</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]313
314<div class="doc_author">
315 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
316 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]317</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]318
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]319<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]320<div class="doc_section"> <a name="abstract">Abstract </a></div>
321<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]322
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]323<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]324
325<p>This document is a reference manual for the LLVM assembly language. LLVM is
326 a Static Single Assignment (SSA) based representation that provides type
327 safety, low-level operations, flexibility, and the capability of representing
328 'all' high-level languages cleanly. It is the common code representation
329 used throughout all phases of the LLVM compilation strategy.</p>
330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]331</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]332
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]333<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]334<div class="doc_section"> <a name="introduction">Introduction</a> </div>
335<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]336
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]337<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]338
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]339<p>The LLVM code representation is designed to be used in three different forms:
340 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
341 for fast loading by a Just-In-Time compiler), and as a human readable
342 assembly language representation. This allows LLVM to provide a powerful
343 intermediate representation for efficient compiler transformations and
344 analysis, while providing a natural means to debug and visualize the
345 transformations. The three different forms of LLVM are all equivalent. This
346 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]348<p>The LLVM representation aims to be light-weight and low-level while being
349 expressive, typed, and extensible at the same time. It aims to be a
350 "universal IR" of sorts, by being at a low enough level that high-level ideas
351 may be cleanly mapped to it (similar to how microprocessors are "universal
352 IR's", allowing many source languages to be mapped to them). By providing
353 type information, LLVM can be used as the target of optimizations: for
354 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]355 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]356 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]357
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]358</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]360<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]361<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]362
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]363<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]365<p>It is important to note that this document describes 'well formed' LLVM
366 assembly language. There is a difference between what the parser accepts and
367 what is considered 'well formed'. For example, the following instruction is
368 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]370<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]371<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]372%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]373</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]374</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]376<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
377 LLVM infrastructure provides a verification pass that may be used to verify
378 that an LLVM module is well formed. This pass is automatically run by the
379 parser after parsing input assembly and by the optimizer before it outputs
380 bitcode. The violations pointed out by the verifier pass indicate bugs in
381 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]382
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]384
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]385<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]386
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]387<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]388<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]389<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]390
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]391<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]393<p>LLVM identifiers come in two basic types: global and local. Global
394 identifiers (functions, global variables) begin with the <tt>'@'</tt>
395 character. Local identifiers (register names, types) begin with
396 the <tt>'%'</tt> character. Additionally, there are three different formats
397 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]398
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]399<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]400 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]401 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
402 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
403 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
404 other characters in their names can be surrounded with quotes. Special
405 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
406 ASCII code for the character in hexadecimal. In this way, any character
407 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]408
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]409 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]410 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]412 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]413 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]414</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]415
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]416<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]417 don't need to worry about name clashes with reserved words, and the set of
418 reserved words may be expanded in the future without penalty. Additionally,
419 unnamed identifiers allow a compiler to quickly come up with a temporary
420 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]422<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]423 languages. There are keywords for different opcodes
424 ('<tt><a href="#i_add">add</a></tt>',
425 '<tt><a href="#i_bitcast">bitcast</a></tt>',
426 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
427 ('<tt><a href="#t_void">void</a></tt>',
428 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
429 reserved words cannot conflict with variable names, because none of them
430 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]431
432<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]433 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]434
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]435<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]437<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]439%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]441</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]443<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]445<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]447%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]449</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]450
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]451<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]453<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454<pre>
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]455%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
456%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]457%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]459</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]460
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]461<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
462 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]475 demonstrating instructions, we will follow an instruction with a comment that
476 defines the type and name of value produced. Comments are shown in italic
477 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
482<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
483<!-- *********************************************************************** -->
484
485<!-- ======================================================================= -->
486<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
487</div>
488
489<div class="doc_text">
490
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]491<p>LLVM programs are composed of "Module"s, each of which is a translation unit
492 of the input programs. Each module consists of functions, global variables,
493 and symbol table entries. Modules may be combined together with the LLVM
494 linker, which merges function (and global variable) definitions, resolves
495 forward declarations, and merges symbol table entries. Here is an example of
496 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]498<div class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]499<pre>
500<i>; Declare the string constant as a global constant.</i>
501<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
503<i>; External declaration of the puts function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]504<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>
508 <i>; Convert [13 x i8]* to i8 *...</i>
509 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]510
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>
512 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]513 <a href="#i_ret">ret</a> i32 0<br>}
514
515<i>; Named metadata</i>
516!1 = metadata !{i32 41}
517!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]518</pre>
519</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]521<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]527<p>In general, a module is made up of a list of global values, where both
528 functions and global variables are global values. Global values are
529 represented by a pointer to a memory location (in this case, a pointer to an
530 array of char, and a pointer to a function), and have one of the
531 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
536<div class="doc_subsection">
537 <a name="linkage">Linkage Types</a>
538</div>
539
540<div class="doc_text">
541
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]547 <dd>Global values with private linkage are only directly accessible by objects
548 in the current module. In particular, linking code into a module with an
549 private global value may cause the private to be renamed as necessary to
550 avoid collisions. Because the symbol is private to the module, all
551 references can be updated. This doesn't show up in any symbol table in the
552 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]555 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere1eaf912009-08-24 04:32:16 +0000[diff] [blame]556 removed by the linker after evaluation. Note that (unlike private
557 symbols) linker_private symbols are subject to coalescing by the linker:
558 weak symbols get merged and redefinitions are rejected. However, unlike
559 normal strong symbols, they are removed by the linker from the final
560 linked image (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]561
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]562 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]563 <dd>Similar to private, but the value shows as a local symbol
564 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
565 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]566
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]567 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]568 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]569 into the object file corresponding to the LLVM module. They exist to
570 allow inlining and other optimizations to take place given knowledge of
571 the definition of the global, which is known to be somewhere outside the
572 module. Globals with <tt>available_externally</tt> linkage are allowed to
573 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
574 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]575
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]577 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]578 the same name when linkage occurs. This can be used to implement
579 some forms of inline functions, templates, or other code which must be
580 generated in each translation unit that uses it, but where the body may
581 be overridden with a more definitive definition later. Unreferenced
582 <tt>linkonce</tt> globals are allowed to be discarded. Note that
583 <tt>linkonce</tt> linkage does not actually allow the optimizer to
584 inline the body of this function into callers because it doesn't know if
585 this definition of the function is the definitive definition within the
586 program or whether it will be overridden by a stronger definition.
587 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
588 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]589
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]591 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
592 <tt>linkonce</tt> linkage, except that unreferenced globals with
593 <tt>weak</tt> linkage may not be discarded. This is used for globals that
594 are declared "weak" in C source code.</dd>
595
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]596 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]597 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
598 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
599 global scope.
600 Symbols with "<tt>common</tt>" linkage are merged in the same way as
601 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]602 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]603 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]604 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
605 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]606
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]607
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]609 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]610 pointer to array type. When two global variables with appending linkage
611 are linked together, the two global arrays are appended together. This is
612 the LLVM, typesafe, equivalent of having the system linker append together
613 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]614
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]615 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]616 <dd>The semantics of this linkage follow the ELF object file model: the symbol
617 is weak until linked, if not linked, the symbol becomes null instead of
618 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]619
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]620 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
621 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]622 <dd>Some languages allow differing globals to be merged, such as two functions
623 with different semantics. Other languages, such as <tt>C++</tt>, ensure
624 that only equivalent globals are ever merged (the "one definition rule" -
625 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
626 and <tt>weak_odr</tt> linkage types to indicate that the global will only
627 be merged with equivalent globals. These linkage types are otherwise the
628 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]629
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]630 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]631 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]632 visible, meaning that it participates in linkage and can be used to
633 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]634</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]635
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]636<p>The next two types of linkage are targeted for Microsoft Windows platform
637 only. They are designed to support importing (exporting) symbols from (to)
638 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]639
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]640<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]641 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]642 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]643 or variable via a global pointer to a pointer that is set up by the DLL
644 exporting the symbol. On Microsoft Windows targets, the pointer name is
645 formed by combining <code>__imp_</code> and the function or variable
646 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]647
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]648 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]649 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]650 pointer to a pointer in a DLL, so that it can be referenced with the
651 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
652 name is formed by combining <code>__imp_</code> and the function or
653 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]654</dl>
655
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
657 another module defined a "<tt>.LC0</tt>" variable and was linked with this
658 one, one of the two would be renamed, preventing a collision. Since
659 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
660 declarations), they are accessible outside of the current module.</p>
661
662<p>It is illegal for a function <i>declaration</i> to have any linkage type
663 other than "externally visible", <tt>dllimport</tt>
664 or <tt>extern_weak</tt>.</p>
665
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]666<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]667 or <tt>weak_odr</tt> linkages.</p>
668
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]669</div>
670
671<!-- ======================================================================= -->
672<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]673 <a name="callingconv">Calling Conventions</a>
674</div>
675
676<div class="doc_text">
677
678<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]679 and <a href="#i_invoke">invokes</a> can all have an optional calling
680 convention specified for the call. The calling convention of any pair of
681 dynamic caller/callee must match, or the behavior of the program is
682 undefined. The following calling conventions are supported by LLVM, and more
683 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]684
685<dl>
686 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]687 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]688 specified) matches the target C calling conventions. This calling
689 convention supports varargs function calls and tolerates some mismatch in
690 the declared prototype and implemented declaration of the function (as
691 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]692
693 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]694 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]695 (e.g. by passing things in registers). This calling convention allows the
696 target to use whatever tricks it wants to produce fast code for the
697 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]698 (Application Binary Interface).
699 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]700 when this or the GHC convention is used.</a> This calling convention
701 does not support varargs and requires the prototype of all callees to
702 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]703
704 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]706 as possible under the assumption that the call is not commonly executed.
707 As such, these calls often preserve all registers so that the call does
708 not break any live ranges in the caller side. This calling convention
709 does not support varargs and requires the prototype of all callees to
710 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]711
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]712 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
713 <dd>This calling convention has been implemented specifically for use by the
714 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
715 It passes everything in registers, going to extremes to achieve this by
716 disabling callee save registers. This calling convention should not be
717 used lightly but only for specific situations such as an alternative to
718 the <em>register pinning</em> performance technique often used when
719 implementing functional programming languages.At the moment only X86
720 supports this convention and it has the following limitations:
721 <ul>
722 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
723 floating point types are supported.</li>
724 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
725 6 floating point parameters.</li>
726 </ul>
727 This calling convention supports
728 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
729 requires both the caller and callee are using it.
730 </dd>
731
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]732 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]733 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]734 target-specific calling conventions to be used. Target specific calling
735 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]736</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]737
738<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]739 support Pascal conventions or any other well-known target-independent
740 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]741
742</div>
743
744<!-- ======================================================================= -->
745<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]746 <a name="visibility">Visibility Styles</a>
747</div>
748
749<div class="doc_text">
750
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]751<p>All Global Variables and Functions have one of the following visibility
752 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]753
754<dl>
755 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]756 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]757 that the declaration is visible to other modules and, in shared libraries,
758 means that the declared entity may be overridden. On Darwin, default
759 visibility means that the declaration is visible to other modules. Default
760 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]761
762 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]763 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]764 object if they are in the same shared object. Usually, hidden visibility
765 indicates that the symbol will not be placed into the dynamic symbol
766 table, so no other module (executable or shared library) can reference it
767 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]768
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]769 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]770 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]771 the dynamic symbol table, but that references within the defining module
772 will bind to the local symbol. That is, the symbol cannot be overridden by
773 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]774</dl>
775
776</div>
777
778<!-- ======================================================================= -->
779<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]780 <a name="namedtypes">Named Types</a>
781</div>
782
783<div class="doc_text">
784
785<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]786 it easier to read the IR and make the IR more condensed (particularly when
787 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]788
789<div class="doc_code">
790<pre>
791%mytype = type { %mytype*, i32 }
792</pre>
793</div>
794
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]795<p>You may give a name to any <a href="#typesystem">type</a> except
796 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
797 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]798
799<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]800 and that you can therefore specify multiple names for the same type. This
801 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
802 uses structural typing, the name is not part of the type. When printing out
803 LLVM IR, the printer will pick <em>one name</em> to render all types of a
804 particular shape. This means that if you have code where two different
805 source types end up having the same LLVM type, that the dumper will sometimes
806 print the "wrong" or unexpected type. This is an important design point and
807 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]808
809</div>
810
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]811<!-- ======================================================================= -->
812<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]813 <a name="globalvars">Global Variables</a>
814</div>
815
816<div class="doc_text">
817
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]818<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]819 instead of run-time. Global variables may optionally be initialized, may
820 have an explicit section to be placed in, and may have an optional explicit
821 alignment specified. A variable may be defined as "thread_local", which
822 means that it will not be shared by threads (each thread will have a
823 separated copy of the variable). A variable may be defined as a global
824 "constant," which indicates that the contents of the variable
825 will <b>never</b> be modified (enabling better optimization, allowing the
826 global data to be placed in the read-only section of an executable, etc).
827 Note that variables that need runtime initialization cannot be marked
828 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]829
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]830<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
831 constant, even if the final definition of the global is not. This capability
832 can be used to enable slightly better optimization of the program, but
833 requires the language definition to guarantee that optimizations based on the
834 'constantness' are valid for the translation units that do not include the
835 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]836
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]837<p>As SSA values, global variables define pointer values that are in scope
838 (i.e. they dominate) all basic blocks in the program. Global variables
839 always define a pointer to their "content" type because they describe a
840 region of memory, and all memory objects in LLVM are accessed through
841 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]842
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]843<p>A global variable may be declared to reside in a target-specific numbered
844 address space. For targets that support them, address spaces may affect how
845 optimizations are performed and/or what target instructions are used to
846 access the variable. The default address space is zero. The address space
847 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]848
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]849<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]850 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]851
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]852<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]853 the alignment is set to zero, the alignment of the global is set by the
854 target to whatever it feels convenient. If an explicit alignment is
855 specified, the global is forced to have at least that much alignment. All
856 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]857
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]858<p>For example, the following defines a global in a numbered address space with
859 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]860
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]861<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]862<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]863@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]864</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]865</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]866
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]867</div>
868
869
870<!-- ======================================================================= -->
871<div class="doc_subsection">
872 <a name="functionstructure">Functions</a>
873</div>
874
875<div class="doc_text">
876
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]877<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]878 optional <a href="#linkage">linkage type</a>, an optional
879 <a href="#visibility">visibility style</a>, an optional
880 <a href="#callingconv">calling convention</a>, a return type, an optional
881 <a href="#paramattrs">parameter attribute</a> for the return type, a function
882 name, a (possibly empty) argument list (each with optional
883 <a href="#paramattrs">parameter attributes</a>), optional
884 <a href="#fnattrs">function attributes</a>, an optional section, an optional
885 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
886 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]887
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]888<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
889 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]890 <a href="#visibility">visibility style</a>, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]891 <a href="#callingconv">calling convention</a>, a return type, an optional
892 <a href="#paramattrs">parameter attribute</a> for the return type, a function
893 name, a possibly empty list of arguments, an optional alignment, and an
894 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]895
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]896<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]897 (Control Flow Graph) for the function. Each basic block may optionally start
898 with a label (giving the basic block a symbol table entry), contains a list
899 of instructions, and ends with a <a href="#terminators">terminator</a>
900 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]901
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]902<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]903 executed on entrance to the function, and it is not allowed to have
904 predecessor basic blocks (i.e. there can not be any branches to the entry
905 block of a function). Because the block can have no predecessors, it also
906 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]907
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]908<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]909 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]910
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]911<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]912 the alignment is set to zero, the alignment of the function is set by the
913 target to whatever it feels convenient. If an explicit alignment is
914 specified, the function is forced to have at least that much alignment. All
915 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]916
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]917<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]918<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]919<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]920define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]921 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
922 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
923 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
924 [<a href="#gc">gc</a>] { ... }
925</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]926</div>
927
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]928</div>
929
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]930<!-- ======================================================================= -->
931<div class="doc_subsection">
932 <a name="aliasstructure">Aliases</a>
933</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]934
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]935<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]936
937<p>Aliases act as "second name" for the aliasee value (which can be either
938 function, global variable, another alias or bitcast of global value). Aliases
939 may have an optional <a href="#linkage">linkage type</a>, and an
940 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]941
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]943<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]944<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]945@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]946</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]947</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]948
949</div>
950
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]951<!-- ======================================================================= -->
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]952<div class="doc_subsection">
953 <a name="namedmetadatastructure">Named Metadata</a>
954</div>
955
956<div class="doc_text">
957
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]958<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
959 nodes</a> (but not metadata strings) and null are the only valid operands for
960 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]961
962<h5>Syntax:</h5>
963<div class="doc_code">
964<pre>
965!1 = metadata !{metadata !"one"}
966!name = !{null, !1}
967</pre>
968</div>
969
970</div>
971
972<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]973<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]974
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]975<div class="doc_text">
976
977<p>The return type and each parameter of a function type may have a set of
978 <i>parameter attributes</i> associated with them. Parameter attributes are
979 used to communicate additional information about the result or parameters of
980 a function. Parameter attributes are considered to be part of the function,
981 not of the function type, so functions with different parameter attributes
982 can have the same function type.</p>
983
984<p>Parameter attributes are simple keywords that follow the type specified. If
985 multiple parameter attributes are needed, they are space separated. For
986 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]987
988<div class="doc_code">
989<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]990declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]991declare i32 @atoi(i8 zeroext)
992declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]993</pre>
994</div>
995
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]996<p>Note that any attributes for the function result (<tt>nounwind</tt>,
997 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]999<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1000
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1001<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1002 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1003 <dd>This indicates to the code generator that the parameter or return value
1004 should be zero-extended to a 32-bit value by the caller (for a parameter)
1005 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1006
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1007 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1008 <dd>This indicates to the code generator that the parameter or return value
1009 should be sign-extended to a 32-bit value by the caller (for a parameter)
1010 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1011
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1012 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1013 <dd>This indicates that this parameter or return value should be treated in a
1014 special target-dependent fashion during while emitting code for a function
1015 call or return (usually, by putting it in a register as opposed to memory,
1016 though some targets use it to distinguish between two different kinds of
1017 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1018
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1019 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1020 <dd>This indicates that the pointer parameter should really be passed by value
1021 to the function. The attribute implies that a hidden copy of the pointee
1022 is made between the caller and the callee, so the callee is unable to
1023 modify the value in the callee. This attribute is only valid on LLVM
1024 pointer arguments. It is generally used to pass structs and arrays by
1025 value, but is also valid on pointers to scalars. The copy is considered
1026 to belong to the caller not the callee (for example,
1027 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1028 <tt>byval</tt> parameters). This is not a valid attribute for return
1029 values. The byval attribute also supports specifying an alignment with
1030 the align attribute. This has a target-specific effect on the code
1031 generator that usually indicates a desired alignment for the synthesized
1032 stack slot.</dd>
1033
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1034 <dt><tt><b>sret</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1035 <dd>This indicates that the pointer parameter specifies the address of a
1036 structure that is the return value of the function in the source program.
1037 This pointer must be guaranteed by the caller to be valid: loads and
1038 stores to the structure may be assumed by the callee to not to trap. This
1039 may only be applied to the first parameter. This is not a valid attribute
1040 for return values. </dd>
1041
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1042 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This indicates that the pointer does not alias any global or any other
1044 parameter. The caller is responsible for ensuring that this is the
1045 case. On a function return value, <tt>noalias</tt> additionally indicates
1046 that the pointer does not alias any other pointers visible to the
1047 caller. For further details, please see the discussion of the NoAlias
1048 response in
1049 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1050 analysis</a>.</dd>
1051
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1052 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1053 <dd>This indicates that the callee does not make any copies of the pointer
1054 that outlive the callee itself. This is not a valid attribute for return
1055 values.</dd>
1056
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1057 <dt><tt><b>nest</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1058 <dd>This indicates that the pointer parameter can be excised using the
1059 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1060 attribute for return values.</dd>
1061</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1062
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1063</div>
1064
1065<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1066<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1067 <a name="gc">Garbage Collector Names</a>
1068</div>
1069
1070<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1071
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1072<p>Each function may specify a garbage collector name, which is simply a
1073 string:</p>
1074
1075<div class="doc_code">
1076<pre>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1077define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1078</pre>
1079</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1080
1081<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1082 collector which will cause the compiler to alter its output in order to
1083 support the named garbage collection algorithm.</p>
1084
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1085</div>
1086
1087<!-- ======================================================================= -->
1088<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1089 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1090</div>
1091
1092<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1093
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1094<p>Function attributes are set to communicate additional information about a
1095 function. Function attributes are considered to be part of the function, not
1096 of the function type, so functions with different parameter attributes can
1097 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1098
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099<p>Function attributes are simple keywords that follow the type specified. If
1100 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1101
1102<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1103<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1104define void @f() noinline { ... }
1105define void @f() alwaysinline { ... }
1106define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1107define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1108</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1109</div>
1110
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1111<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1112 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1113 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1114 the backend should forcibly align the stack pointer. Specify the
1115 desired alignment, which must be a power of two, in parentheses.
1116
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1117 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1118 <dd>This attribute indicates that the inliner should attempt to inline this
1119 function into callers whenever possible, ignoring any active inlining size
1120 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1121
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1122 <dt><tt><b>inlinehint</b></tt></dt>
1123 <dd>This attribute indicates that the source code contained a hint that inlining
1124 this function is desirable (such as the "inline" keyword in C/C++). It
1125 is just a hint; it imposes no requirements on the inliner.</dd>
1126
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1127 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1128 <dd>This attribute indicates that the inliner should never inline this
1129 function in any situation. This attribute may not be used together with
1130 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1131
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1132 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1133 <dd>This attribute suggests that optimization passes and code generator passes
1134 make choices that keep the code size of this function low, and otherwise
1135 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1137 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1138 <dd>This function attribute indicates that the function never returns
1139 normally. This produces undefined behavior at runtime if the function
1140 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1141
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1142 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1143 <dd>This function attribute indicates that the function never returns with an
1144 unwind or exceptional control flow. If the function does unwind, its
1145 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1146
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1147 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1148 <dd>This attribute indicates that the function computes its result (or decides
1149 to unwind an exception) based strictly on its arguments, without
1150 dereferencing any pointer arguments or otherwise accessing any mutable
1151 state (e.g. memory, control registers, etc) visible to caller functions.
1152 It does not write through any pointer arguments
1153 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1154 changes any state visible to callers. This means that it cannot unwind
1155 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1156 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1157
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1158 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1159 <dd>This attribute indicates that the function does not write through any
1160 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1161 arguments) or otherwise modify any state (e.g. memory, control registers,
1162 etc) visible to caller functions. It may dereference pointer arguments
1163 and read state that may be set in the caller. A readonly function always
1164 returns the same value (or unwinds an exception identically) when called
1165 with the same set of arguments and global state. It cannot unwind an
1166 exception by calling the <tt>C++</tt> exception throwing methods, but may
1167 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1168
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1169 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1170 <dd>This attribute indicates that the function should emit a stack smashing
1171 protector. It is in the form of a "canary"&mdash;a random value placed on
1172 the stack before the local variables that's checked upon return from the
1173 function to see if it has been overwritten. A heuristic is used to
1174 determine if a function needs stack protectors or not.<br>
1175<br>
1176 If a function that has an <tt>ssp</tt> attribute is inlined into a
1177 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1178 function will have an <tt>ssp</tt> attribute.</dd>
1179
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1180 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1181 <dd>This attribute indicates that the function should <em>always</em> emit a
1182 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1183 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1184<br>
1185 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1186 function that doesn't have an <tt>sspreq</tt> attribute or which has
1187 an <tt>ssp</tt> attribute, then the resulting function will have
1188 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1189
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1190 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1191 <dd>This attribute indicates that the code generator should not use a red
1192 zone, even if the target-specific ABI normally permits it.</dd>
1193
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1194 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1195 <dd>This attributes disables implicit floating point instructions.</dd>
1196
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>naked</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This attribute disables prologue / epilogue emission for the function.
1199 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1200</dl>
1201
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1202</div>
1203
1204<!-- ======================================================================= -->
1205<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1206 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1207</div>
1208
1209<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1210
1211<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1212 the GCC "file scope inline asm" blocks. These blocks are internally
1213 concatenated by LLVM and treated as a single unit, but may be separated in
1214 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1215
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1216<div class="doc_code">
1217<pre>
1218module asm "inline asm code goes here"
1219module asm "more can go here"
1220</pre>
1221</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1222
1223<p>The strings can contain any character by escaping non-printable characters.
1224 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1225 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1226
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1227<p>The inline asm code is simply printed to the machine code .s file when
1228 assembly code is generated.</p>
1229
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1230</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1231
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1232<!-- ======================================================================= -->
1233<div class="doc_subsection">
1234 <a name="datalayout">Data Layout</a>
1235</div>
1236
1237<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1238
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1239<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1240 data is to be laid out in memory. The syntax for the data layout is
1241 simply:</p>
1242
1243<div class="doc_code">
1244<pre>
1245target datalayout = "<i>layout specification</i>"
1246</pre>
1247</div>
1248
1249<p>The <i>layout specification</i> consists of a list of specifications
1250 separated by the minus sign character ('-'). Each specification starts with
1251 a letter and may include other information after the letter to define some
1252 aspect of the data layout. The specifications accepted are as follows:</p>
1253
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1254<dl>
1255 <dt><tt>E</tt></dt>
1256 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1257 bits with the most significance have the lowest address location.</dd>
1258
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1259 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1260 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1261 the bits with the least significance have the lowest address
1262 location.</dd>
1263
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1264 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1265 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1266 <i>preferred</i> alignments. All sizes are in bits. Specifying
1267 the <i>pref</i> alignment is optional. If omitted, the
1268 preceding <tt>:</tt> should be omitted too.</dd>
1269
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1270 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1271 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1272 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1273
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1274 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1275 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1276 <i>size</i>.</dd>
1277
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1278 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1279 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1280 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1281 (double).</dd>
1282
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1283 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1284 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1285 <i>size</i>.</dd>
1286
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1287 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1288 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1289 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1290
1291 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1292 <dd>This specifies a set of native integer widths for the target CPU
1293 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1294 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1295 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1296 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1297</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1298
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1299<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1300 default set of specifications which are then (possibly) overriden by the
1301 specifications in the <tt>datalayout</tt> keyword. The default specifications
1302 are given in this list:</p>
1303
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1304<ul>
1305 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1306 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1307 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1308 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1309 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1310 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1311 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1312 alignment of 64-bits</li>
1313 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1314 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1315 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1316 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1317 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1318 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1319</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1320
1321<p>When LLVM is determining the alignment for a given type, it uses the
1322 following rules:</p>
1323
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1324<ol>
1325 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1326 specification is used.</li>
1327
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1328 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1329 smallest integer type that is larger than the bitwidth of the sought type
1330 is used. If none of the specifications are larger than the bitwidth then
1331 the the largest integer type is used. For example, given the default
1332 specifications above, the i7 type will use the alignment of i8 (next
1333 largest) while both i65 and i256 will use the alignment of i64 (largest
1334 specified).</li>
1335
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1336 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1337 largest vector type that is smaller than the sought vector type will be
1338 used as a fall back. This happens because &lt;128 x double&gt; can be
1339 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1340</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1341
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1342</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1343
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1344<!-- ======================================================================= -->
1345<div class="doc_subsection">
1346 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1347</div>
1348
1349<div class="doc_text">
1350
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1351<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1352with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1353is undefined. Pointer values are associated with address ranges
1354according to the following rules:</p>
1355
1356<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1357 <li>A pointer value formed from a
1358 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1359 is associated with the addresses associated with the first operand
1360 of the <tt>getelementptr</tt>.</li>
1361 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1362 range of the variable's storage.</li>
1363 <li>The result value of an allocation instruction is associated with
1364 the address range of the allocated storage.</li>
1365 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1366 no address.</li>
1367 <li>A pointer value formed by an
1368 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1369 address ranges of all pointer values that contribute (directly or
1370 indirectly) to the computation of the pointer's value.</li>
1371 <li>The result value of a
1372 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1373 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1374 <li>An integer constant other than zero or a pointer value returned
1375 from a function not defined within LLVM may be associated with address
1376 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1377 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1378 allocated by mechanisms provided by LLVM.</li>
1379 </ul>
1380
1381<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1382<tt><a href="#i_load">load</a></tt> merely indicates the size and
1383alignment of the memory from which to load, as well as the
1384interpretation of the value. The first operand of a
1385<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1386and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1387
1388<p>Consequently, type-based alias analysis, aka TBAA, aka
1389<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1390LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1391additional information which specialized optimization passes may use
1392to implement type-based alias analysis.</p>
1393
1394</div>
1395
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1396<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1397<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1398<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1399
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1400<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1401
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1402<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1403 intermediate representation. Being typed enables a number of optimizations
1404 to be performed on the intermediate representation directly, without having
1405 to do extra analyses on the side before the transformation. A strong type
1406 system makes it easier to read the generated code and enables novel analyses
1407 and transformations that are not feasible to perform on normal three address
1408 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1409
1410</div>
1411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1412<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1413<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1414Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1415
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1416<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1417
1418<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1419
1420<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1421 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1422 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1423 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1424 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1425 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1426 </tr>
1427 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1428 <td><a href="#t_floating">floating point</a></td>
1429 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1430 </tr>
1431 <tr>
1432 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1433 <td><a href="#t_integer">integer</a>,
1434 <a href="#t_floating">floating point</a>,
1435 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1436 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1437 <a href="#t_struct">structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1438 <a href="#t_union">union</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1439 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1440 <a href="#t_label">label</a>,
1441 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1442 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1443 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1444 <tr>
1445 <td><a href="#t_primitive">primitive</a></td>
1446 <td><a href="#t_label">label</a>,
1447 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1448 <a href="#t_floating">floating point</a>,
1449 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1450 </tr>
1451 <tr>
1452 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1453 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1454 <a href="#t_function">function</a>,
1455 <a href="#t_pointer">pointer</a>,
1456 <a href="#t_struct">structure</a>,
1457 <a href="#t_pstruct">packed structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1458 <a href="#t_union">union</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1459 <a href="#t_vector">vector</a>,
1460 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1461 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1462 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1463 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1464</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1465
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1466<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1467 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1468 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1469
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1470</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1472<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1473<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1474
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1475<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1476
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1477<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1478 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1479
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1480</div>
1481
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1482<!-- _______________________________________________________________________ -->
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1483<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1484
1485<div class="doc_text">
1486
1487<h5>Overview:</h5>
1488<p>The integer type is a very simple type that simply specifies an arbitrary
1489 bit width for the integer type desired. Any bit width from 1 bit to
1490 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1491
1492<h5>Syntax:</h5>
1493<pre>
1494 iN
1495</pre>
1496
1497<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1498 value.</p>
1499
1500<h5>Examples:</h5>
1501<table class="layout">
1502 <tr class="layout">
1503 <td class="left"><tt>i1</tt></td>
1504 <td class="left">a single-bit integer.</td>
1505 </tr>
1506 <tr class="layout">
1507 <td class="left"><tt>i32</tt></td>
1508 <td class="left">a 32-bit integer.</td>
1509 </tr>
1510 <tr class="layout">
1511 <td class="left"><tt>i1942652</tt></td>
1512 <td class="left">a really big integer of over 1 million bits.</td>
1513 </tr>
1514</table>
1515
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1516</div>
1517
1518<!-- _______________________________________________________________________ -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1519<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1520
1521<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1522
1523<table>
1524 <tbody>
1525 <tr><th>Type</th><th>Description</th></tr>
1526 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1527 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1528 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1529 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1530 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1531 </tbody>
1532</table>
1533
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1534</div>
1535
1536<!-- _______________________________________________________________________ -->
1537<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1538
1539<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1540
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1541<h5>Overview:</h5>
1542<p>The void type does not represent any value and has no size.</p>
1543
1544<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1545<pre>
1546 void
1547</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1548
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1549</div>
1550
1551<!-- _______________________________________________________________________ -->
1552<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1553
1554<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1555
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1556<h5>Overview:</h5>
1557<p>The label type represents code labels.</p>
1558
1559<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1560<pre>
1561 label
1562</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1563
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1564</div>
1565
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1566<!-- _______________________________________________________________________ -->
1567<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1568
1569<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1570
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1571<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1572<p>The metadata type represents embedded metadata. No derived types may be
1573 created from metadata except for <a href="#t_function">function</a>
1574 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1575
1576<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1577<pre>
1578 metadata
1579</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1580
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1581</div>
1582
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1583
1584<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1585<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1586
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1587<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1588
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1589<p>The real power in LLVM comes from the derived types in the system. This is
1590 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1591 useful types. Each of these types contain one or more element types which
1592 may be a primitive type, or another derived type. For example, it is
1593 possible to have a two dimensional array, using an array as the element type
1594 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1595
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1596
1597</div>
1598
1599<!-- _______________________________________________________________________ -->
1600<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1601
1602<div class="doc_text">
1603
1604<p>Aggregate Types are a subset of derived types that can contain multiple
1605 member types. <a href="#t_array">Arrays</a>,
1606 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1607 <a href="#t_union">unions</a> are aggregate types.</p>
1608
1609</div>
1610
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1611</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1612
1613<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1614<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1615
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1616<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1617
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1618<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1619<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1620 sequentially in memory. The array type requires a size (number of elements)
1621 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1622
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1623<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1624<pre>
1625 [&lt;# elements&gt; x &lt;elementtype&gt;]
1626</pre>
1627
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1628<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1629 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1630
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1631<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1632<table class="layout">
1633 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1634 <td class="left"><tt>[40 x i32]</tt></td>
1635 <td class="left">Array of 40 32-bit integer values.</td>
1636 </tr>
1637 <tr class="layout">
1638 <td class="left"><tt>[41 x i32]</tt></td>
1639 <td class="left">Array of 41 32-bit integer values.</td>
1640 </tr>
1641 <tr class="layout">
1642 <td class="left"><tt>[4 x i8]</tt></td>
1643 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1644 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1645</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1646<p>Here are some examples of multidimensional arrays:</p>
1647<table class="layout">
1648 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1649 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1650 <td class="left">3x4 array of 32-bit integer values.</td>
1651 </tr>
1652 <tr class="layout">
1653 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1654 <td class="left">12x10 array of single precision floating point values.</td>
1655 </tr>
1656 <tr class="layout">
1657 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1658 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1659 </tr>
1660</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1661
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1662<p>There is no restriction on indexing beyond the end of the array implied by
1663 a static type (though there are restrictions on indexing beyond the bounds
1664 of an allocated object in some cases). This means that single-dimension
1665 'variable sized array' addressing can be implemented in LLVM with a zero
1666 length array type. An implementation of 'pascal style arrays' in LLVM could
1667 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1668
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1669</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1671<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1672<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1673
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1674<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1676<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1677<p>The function type can be thought of as a function signature. It consists of
1678 a return type and a list of formal parameter types. The return type of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1679 function type is a scalar type, a void type, a struct type, or a union
1680 type. If the return type is a struct type then all struct elements must be
1681 of first class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1682
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1683<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1684<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1685 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1686</pre>
1687
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1688<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1689 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1690 which indicates that the function takes a variable number of arguments.
1691 Variable argument functions can access their arguments with
1692 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1693 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1694 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1696<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1697<table class="layout">
1698 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1699 <td class="left"><tt>i32 (i32)</tt></td>
1700 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1701 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1702 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1703 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1704 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1705 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1706 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1707 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1708 </td>
1709 </tr><tr class="layout">
1710 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1711 <td class="left">A vararg function that takes at least one
1712 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1713 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1714 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1715 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1716 </tr><tr class="layout">
1717 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1718 <td class="left">A function taking an <tt>i32</tt>, returning a
1719 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1720 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1721 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1722</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1723
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1724</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1725
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1726<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1727<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1728
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1729<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1730
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1731<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1732<p>The structure type is used to represent a collection of data members together
1733 in memory. The packing of the field types is defined to match the ABI of the
1734 underlying processor. The elements of a structure may be any type that has a
1735 size.</p>
1736
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1737<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1738 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1739 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1740 Structures in registers are accessed using the
1741 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1742 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1743<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1744<pre>
1745 { &lt;type list&gt; }
1746</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1747
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1748<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1749<table class="layout">
1750 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1751 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1752 <td class="left">A triple of three <tt>i32</tt> values</td>
1753 </tr><tr class="layout">
1754 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1755 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1756 second element is a <a href="#t_pointer">pointer</a> to a
1757 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1758 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1759 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1760</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1761
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1762</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1763
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1764<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1765<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1766</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1767
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1768<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1769
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1770<h5>Overview:</h5>
1771<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1772 together in memory. There is no padding between fields. Further, the
1773 alignment of a packed structure is 1 byte. The elements of a packed
1774 structure may be any type that has a size.</p>
1775
1776<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1777 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1778 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1779
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1780<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1781<pre>
1782 &lt; { &lt;type list&gt; } &gt;
1783</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1784
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1785<h5>Examples:</h5>
1786<table class="layout">
1787 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1788 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1789 <td class="left">A triple of three <tt>i32</tt> values</td>
1790 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1791 <td class="left">
1792<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1793 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1794 second element is a <a href="#t_pointer">pointer</a> to a
1795 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1796 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1797 </tr>
1798</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1799
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1800</div>
1801
1802<!-- _______________________________________________________________________ -->
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1803<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1804
1805<div class="doc_text">
1806
1807<h5>Overview:</h5>
1808<p>A union type describes an object with size and alignment suitable for
1809 an object of any one of a given set of types (also known as an "untagged"
1810 union). It is similar in concept and usage to a
1811 <a href="#t_struct">struct</a>, except that all members of the union
1812 have an offset of zero. The elements of a union may be any type that has a
1813 size. Unions must have at least one member - empty unions are not allowed.
1814 </p>
1815
1816<p>The size of the union as a whole will be the size of its largest member,
1817 and the alignment requirements of the union as a whole will be the largest
1818 alignment requirement of any member.</p>
1819
Dan Gohman2eddfef2010-02-25 16:51:31 +0000[diff] [blame]1820<p>Union members are accessed using '<tt><a href="#i_load">load</a></tt> and
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1821 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1822 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1823 Since all members are at offset zero, the getelementptr instruction does
1824 not affect the address, only the type of the resulting pointer.</p>
1825
1826<h5>Syntax:</h5>
1827<pre>
1828 union { &lt;type list&gt; }
1829</pre>
1830
1831<h5>Examples:</h5>
1832<table class="layout">
1833 <tr class="layout">
1834 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1835 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1836 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1837 </tr><tr class="layout">
1838 <td class="left">
1839 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1840 <td class="left">A union, where the first element is a <tt>float</tt> and the
1841 second element is a <a href="#t_pointer">pointer</a> to a
1842 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1843 an <tt>i32</tt>.</td>
1844 </tr>
1845</table>
1846
1847</div>
1848
1849<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1850<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1851
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1852<div class="doc_text">
1853
1854<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1855<p>The pointer type is used to specify memory locations.
1856 Pointers are commonly used to reference objects in memory.</p>
1857
1858<p>Pointer types may have an optional address space attribute defining the
1859 numbered address space where the pointed-to object resides. The default
1860 address space is number zero. The semantics of non-zero address
1861 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1862
1863<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1864 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1865
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1866<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1867<pre>
1868 &lt;type&gt; *
1869</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1870
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1871<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1872<table class="layout">
1873 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1874 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1875 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1876 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1877 </tr>
1878 <tr class="layout">
1879 <td class="left"><tt>i32 (i32 *) *</tt></td>
1880 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1881 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1882 <tt>i32</tt>.</td>
1883 </tr>
1884 <tr class="layout">
1885 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1886 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1887 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1888 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1889</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1890
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1891</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1892
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1893<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1894<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1895
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1896<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1897
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1898<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1899<p>A vector type is a simple derived type that represents a vector of elements.
1900 Vector types are used when multiple primitive data are operated in parallel
1901 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1902 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1903 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1904
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1905<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1906<pre>
1907 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1908</pre>
1909
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1910<p>The number of elements is a constant integer value; elementtype may be any
1911 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1912
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1913<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1914<table class="layout">
1915 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1916 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1917 <td class="left">Vector of 4 32-bit integer values.</td>
1918 </tr>
1919 <tr class="layout">
1920 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1921 <td class="left">Vector of 8 32-bit floating-point values.</td>
1922 </tr>
1923 <tr class="layout">
1924 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1925 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1926 </tr>
1927</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1928
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1929</div>
1930
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1931<!-- _______________________________________________________________________ -->
1932<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1933<div class="doc_text">
1934
1935<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1936<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937 corresponds (for example) to the C notion of a forward declared structure
1938 type. In LLVM, opaque types can eventually be resolved to any type (not just
1939 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1940
1941<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1942<pre>
1943 opaque
1944</pre>
1945
1946<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1947<table class="layout">
1948 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1949 <td class="left"><tt>opaque</tt></td>
1950 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1951 </tr>
1952</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1953
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1954</div>
1955
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1956<!-- ======================================================================= -->
1957<div class="doc_subsection">
1958 <a name="t_uprefs">Type Up-references</a>
1959</div>
1960
1961<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1962
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1963<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1964<p>An "up reference" allows you to refer to a lexically enclosing type without
1965 requiring it to have a name. For instance, a structure declaration may
1966 contain a pointer to any of the types it is lexically a member of. Example
1967 of up references (with their equivalent as named type declarations)
1968 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1969
1970<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1971 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1972 { \2 }* %y = type { %y }*
1973 \1* %z = type %z*
1974</pre>
1975
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1976<p>An up reference is needed by the asmprinter for printing out cyclic types
1977 when there is no declared name for a type in the cycle. Because the
1978 asmprinter does not want to print out an infinite type string, it needs a
1979 syntax to handle recursive types that have no names (all names are optional
1980 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1981
1982<h5>Syntax:</h5>
1983<pre>
1984 \&lt;level&gt;
1985</pre>
1986
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1987<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1988
1989<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1990<table class="layout">
1991 <tr class="layout">
1992 <td class="left"><tt>\1*</tt></td>
1993 <td class="left">Self-referential pointer.</td>
1994 </tr>
1995 <tr class="layout">
1996 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1997 <td class="left">Recursive structure where the upref refers to the out-most
1998 structure.</td>
1999 </tr>
2000</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2001
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2002</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2003
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2004<!-- *********************************************************************** -->
2005<div class="doc_section"> <a name="constants">Constants</a> </div>
2006<!-- *********************************************************************** -->
2007
2008<div class="doc_text">
2009
2010<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2011 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2012
2013</div>
2014
2015<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]2016<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2017
2018<div class="doc_text">
2019
2020<dl>
2021 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2022 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2023 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2024
2025 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2026 <dd>Standard integers (such as '4') are constants of
2027 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2028 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2029
2030 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2031 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2032 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2033 notation (see below). The assembler requires the exact decimal value of a
2034 floating-point constant. For example, the assembler accepts 1.25 but
2035 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2036 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2037
2038 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2039 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2040 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2041</dl>
2042
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2043<p>The one non-intuitive notation for constants is the hexadecimal form of
2044 floating point constants. For example, the form '<tt>double
2045 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2046 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2047 constants are required (and the only time that they are generated by the
2048 disassembler) is when a floating point constant must be emitted but it cannot
2049 be represented as a decimal floating point number in a reasonable number of
2050 digits. For example, NaN's, infinities, and other special values are
2051 represented in their IEEE hexadecimal format so that assembly and disassembly
2052 do not cause any bits to change in the constants.</p>
2053
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2054<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2055 represented using the 16-digit form shown above (which matches the IEEE754
2056 representation for double); float values must, however, be exactly
2057 representable as IEE754 single precision. Hexadecimal format is always used
2058 for long double, and there are three forms of long double. The 80-bit format
2059 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2060 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2061 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2062 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2063 currently supported target uses this format. Long doubles will only work if
2064 they match the long double format on your target. All hexadecimal formats
2065 are big-endian (sign bit at the left).</p>
2066
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2067</div>
2068
2069<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2070<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2071<a name="aggregateconstants"></a> <!-- old anchor -->
2072<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2073</div>
2074
2075<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2076
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2077<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2078 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2079
2080<dl>
2081 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2082 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2083 type definitions (a comma separated list of elements, surrounded by braces
2084 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2085 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2086 Structure constants must have <a href="#t_struct">structure type</a>, and
2087 the number and types of elements must match those specified by the
2088 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2089
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2090 <dt><b>Union constants</b></dt>
2091 <dd>Union constants are represented with notation similar to a structure with
2092 a single element - that is, a single typed element surrounded
2093 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2094 <a href="#t_union">union type</a> can be initialized with a single-element
2095 struct as long as the type of the struct element matches the type of
2096 one of the union members.</dd>
2097
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2098 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2099 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2100 definitions (a comma separated list of elements, surrounded by square
2101 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2102 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2103 the number and types of elements must match those specified by the
2104 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2105
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2106 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2107 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2108 definitions (a comma separated list of elements, surrounded by
2109 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2110 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2111 have <a href="#t_vector">vector type</a>, and the number and types of
2112 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2113
2114 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2115 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2116 value to zero of <em>any</em> type, including scalar and
2117 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2118 This is often used to avoid having to print large zero initializers
2119 (e.g. for large arrays) and is always exactly equivalent to using explicit
2120 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2121
2122 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2123 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2124 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2125 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2126 be interpreted as part of the instruction stream, metadata is a place to
2127 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2128</dl>
2129
2130</div>
2131
2132<!-- ======================================================================= -->
2133<div class="doc_subsection">
2134 <a name="globalconstants">Global Variable and Function Addresses</a>
2135</div>
2136
2137<div class="doc_text">
2138
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2139<p>The addresses of <a href="#globalvars">global variables</a>
2140 and <a href="#functionstructure">functions</a> are always implicitly valid
2141 (link-time) constants. These constants are explicitly referenced when
2142 the <a href="#identifiers">identifier for the global</a> is used and always
2143 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2144 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2145
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2146<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2147<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2148@X = global i32 17
2149@Y = global i32 42
2150@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2151</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2152</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2153
2154</div>
2155
2156<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2157<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2158<div class="doc_text">
2159
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2160<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2161 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2162 Undefined values may be of any type (other than label or void) and be used
2163 anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2164
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2165<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2166 program is well defined no matter what value is used. This gives the
2167 compiler more freedom to optimize. Here are some examples of (potentially
2168 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2169
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2170
2171<div class="doc_code">
2172<pre>
2173 %A = add %X, undef
2174 %B = sub %X, undef
2175 %C = xor %X, undef
2176Safe:
2177 %A = undef
2178 %B = undef
2179 %C = undef
2180</pre>
2181</div>
2182
2183<p>This is safe because all of the output bits are affected by the undef bits.
2184Any output bit can have a zero or one depending on the input bits.</p>
2185
2186<div class="doc_code">
2187<pre>
2188 %A = or %X, undef
2189 %B = and %X, undef
2190Safe:
2191 %A = -1
2192 %B = 0
2193Unsafe:
2194 %A = undef
2195 %B = undef
2196</pre>
2197</div>
2198
2199<p>These logical operations have bits that are not always affected by the input.
2200For example, if "%X" has a zero bit, then the output of the 'and' operation will
2201always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2202such, it is unsafe to optimize or assume that the result of the and is undef.
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2203However, it is safe to assume that all bits of the undef could be 0, and
2204optimize the and to 0. Likewise, it is safe to assume that all the bits of
2205the undef operand to the or could be set, allowing the or to be folded to
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2206-1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2207
2208<div class="doc_code">
2209<pre>
2210 %A = select undef, %X, %Y
2211 %B = select undef, 42, %Y
2212 %C = select %X, %Y, undef
2213Safe:
2214 %A = %X (or %Y)
2215 %B = 42 (or %Y)
2216 %C = %Y
2217Unsafe:
2218 %A = undef
2219 %B = undef
2220 %C = undef
2221</pre>
2222</div>
2223
2224<p>This set of examples show that undefined select (and conditional branch)
2225conditions can go "either way" but they have to come from one of the two
2226operands. In the %A example, if %X and %Y were both known to have a clear low
2227bit, then %A would have to have a cleared low bit. However, in the %C example,
2228the optimizer is allowed to assume that the undef operand could be the same as
2229%Y, allowing the whole select to be eliminated.</p>
2230
2231
2232<div class="doc_code">
2233<pre>
2234 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2235
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2236 %B = undef
2237 %C = xor %B, %B
2238
2239 %D = undef
2240 %E = icmp lt %D, 4
2241 %F = icmp gte %D, 4
2242
2243Safe:
2244 %A = undef
2245 %B = undef
2246 %C = undef
2247 %D = undef
2248 %E = undef
2249 %F = undef
2250</pre>
2251</div>
2252
2253<p>This example points out that two undef operands are not necessarily the same.
2254This can be surprising to people (and also matches C semantics) where they
2255assume that "X^X" is always zero, even if X is undef. This isn't true for a
2256number of reasons, but the short answer is that an undef "variable" can
2257arbitrarily change its value over its "live range". This is true because the
2258"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2259logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2260so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner349eb412009-09-08 15:13:16 +0000[diff] [blame]2261to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2262would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2263
2264<div class="doc_code">
2265<pre>
2266 %A = fdiv undef, %X
2267 %B = fdiv %X, undef
2268Safe:
2269 %A = undef
2270b: unreachable
2271</pre>
2272</div>
2273
2274<p>These examples show the crucial difference between an <em>undefined
2275value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2276allowed to have an arbitrary bit-pattern. This means that the %A operation
2277can be constant folded to undef because the undef could be an SNaN, and fdiv is
2278not (currently) defined on SNaN's. However, in the second example, we can make
2279a more aggressive assumption: because the undef is allowed to be an arbitrary
2280value, we are allowed to assume that it could be zero. Since a divide by zero
Chris Lattner8e371aa2009-09-08 19:45:34 +0000[diff] [blame]2281has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2282does not execute at all. This allows us to delete the divide and all code after
2283it: since the undefined operation "can't happen", the optimizer can assume that
2284it occurs in dead code.
2285</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2286
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2287<div class="doc_code">
2288<pre>
2289a: store undef -> %X
2290b: store %X -> undef
2291Safe:
2292a: &lt;deleted&gt;
2293b: unreachable
2294</pre>
2295</div>
2296
2297<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2298can be assumed to not have any effect: we can assume that the value is
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2299overwritten with bits that happen to match what was already there. However, a
2300store "to" an undefined location could clobber arbitrary memory, therefore, it
2301has undefined behavior.</p>
2302
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2303</div>
2304
2305<!-- ======================================================================= -->
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2306<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2307 Blocks</a></div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2308<div class="doc_text">
2309
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2310<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2311
2312<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2313 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2314 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2315
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2316<p>This value only has defined behavior when used as an operand to the
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2317 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2318 against null. Pointer equality tests between labels addresses is undefined
2319 behavior - though, again, comparison against null is ok, and no label is
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2320 equal to the null pointer. This may also be passed around as an opaque
2321 pointer sized value as long as the bits are not inspected. This allows
Chris Lattner3fd77ce2009-10-27 21:44:20 +0000[diff] [blame]2322 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2323 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2324
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2325<p>Finally, some targets may provide defined semantics when
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2326 using the value as the operand to an inline assembly, but that is target
2327 specific.
2328 </p>
2329
2330</div>
2331
2332
2333<!-- ======================================================================= -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2334<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2335</div>
2336
2337<div class="doc_text">
2338
2339<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2340 to be used as constants. Constant expressions may be of
2341 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2342 operation that does not have side effects (e.g. load and call are not
2343 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2344
2345<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2346 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2347 <dd>Truncate a constant to another type. The bit size of CST must be larger
2348 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2349
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2350 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2351 <dd>Zero extend a constant to another type. The bit size of CST must be
2352 smaller or equal to the bit size of TYPE. Both types must be
2353 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2354
2355 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2356 <dd>Sign extend a constant to another type. The bit size of CST must be
2357 smaller or equal to the bit size of TYPE. Both types must be
2358 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2359
2360 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2361 <dd>Truncate a floating point constant to another floating point type. The
2362 size of CST must be larger than the size of TYPE. Both types must be
2363 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2364
2365 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2366 <dd>Floating point extend a constant to another type. The size of CST must be
2367 smaller or equal to the size of TYPE. Both types must be floating
2368 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2369
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2370 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2371 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2372 constant. TYPE must be a scalar or vector integer type. CST must be of
2373 scalar or vector floating point type. Both CST and TYPE must be scalars,
2374 or vectors of the same number of elements. If the value won't fit in the
2375 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2376
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2377 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2378 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2379 constant. TYPE must be a scalar or vector integer type. CST must be of
2380 scalar or vector floating point type. Both CST and TYPE must be scalars,
2381 or vectors of the same number of elements. If the value won't fit in the
2382 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2383
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2384 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2385 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2386 constant. TYPE must be a scalar or vector floating point type. CST must be
2387 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2388 vectors of the same number of elements. If the value won't fit in the
2389 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2390
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2391 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2392 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2393 constant. TYPE must be a scalar or vector floating point type. CST must be
2394 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2395 vectors of the same number of elements. If the value won't fit in the
2396 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2397
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2398 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2399 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2400 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2401 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2402 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2403
2404 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2405 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2406 type. CST must be of integer type. The CST value is zero extended,
2407 truncated, or unchanged to make it fit in a pointer size. This one is
2408 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2409
2410 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2411 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2412 are the same as those for the <a href="#i_bitcast">bitcast
2413 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2414
2415 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2416 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2417 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2418 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2419 instruction, the index list may have zero or more indexes, which are
2420 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2421
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2422 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2423 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2424
2425 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2426 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2427
2428 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2429 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2430
2431 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2432 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2433 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2434
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2435 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2436 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2437 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2438
2439 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2440 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2441 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2442
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2443 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2444 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2445 be any of the <a href="#binaryops">binary</a>
2446 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2447 on operands are the same as those for the corresponding instruction
2448 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2449</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2450
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2451</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2452
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2453<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2454<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2455<!-- *********************************************************************** -->
2456
2457<!-- ======================================================================= -->
2458<div class="doc_subsection">
2459<a name="inlineasm">Inline Assembler Expressions</a>
2460</div>
2461
2462<div class="doc_text">
2463
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2464<p>LLVM supports inline assembler expressions (as opposed
2465 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2466 a special value. This value represents the inline assembler as a string
2467 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2468 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2469 expression has side effects, and a flag indicating whether the function
2470 containing the asm needs to align its stack conservatively. An example
2471 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2472
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2473<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2474<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2475i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2476</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2477</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2478
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2479<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2480 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2481 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2482
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2483<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2484<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2485%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2486</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2487</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2488
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2489<p>Inline asms with side effects not visible in the constraint list must be
2490 marked as having side effects. This is done through the use of the
2491 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2492
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2493<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2494<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2495call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2496</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2497</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2498
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2499<p>In some cases inline asms will contain code that will not work unless the
2500 stack is aligned in some way, such as calls or SSE instructions on x86,
2501 yet will not contain code that does that alignment within the asm.
2502 The compiler should make conservative assumptions about what the asm might
2503 contain and should generate its usual stack alignment code in the prologue
2504 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2505
2506<div class="doc_code">
2507<pre>
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2508call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2509</pre>
2510</div>
2511
2512<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2513 first.</p>
2514
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2515<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2516 documented here. Constraints on what can be done (e.g. duplication, moving,
2517 etc need to be documented). This is probably best done by reference to
2518 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2519</div>
2520
2521<div class="doc_subsubsection">
2522<a name="inlineasm_md">Inline Asm Metadata</a>
2523</div>
2524
2525<div class="doc_text">
2526
2527<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
2528 attached to it that contains a constant integer. If present, the code
2529 generator will use the integer as the location cookie value when report
2530 errors through the LLVMContext error reporting mechanisms. This allows a
2531 front-end to corrolate backend errors that occur with inline asm back to the
2532 source code that produced it. For example:</p>
2533
2534<div class="doc_code">
2535<pre>
2536call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2537...
2538!42 = !{ i32 1234567 }
2539</pre>
2540</div>
2541
2542<p>It is up to the front-end to make sense of the magic numbers it places in the
2543 IR.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2544
2545</div>
2546
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2547<!-- ======================================================================= -->
2548<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2549 Strings</a>
2550</div>
2551
2552<div class="doc_text">
2553
2554<p>LLVM IR allows metadata to be attached to instructions in the program that
2555 can convey extra information about the code to the optimizers and code
2556 generator. One example application of metadata is source-level debug
2557 information. There are two metadata primitives: strings and nodes. All
2558 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2559 preceding exclamation point ('<tt>!</tt>').</p>
2560
2561<p>A metadata string is a string surrounded by double quotes. It can contain
2562 any character by escaping non-printable characters with "\xx" where "xx" is
2563 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2564
2565<p>Metadata nodes are represented with notation similar to structure constants
2566 (a comma separated list of elements, surrounded by braces and preceded by an
2567 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2568 10}</tt>". Metadata nodes can have any values as their operand.</p>
2569
2570<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2571 metadata nodes, which can be looked up in the module symbol table. For
2572 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2573
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2574<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
2575 function is using two metadata arguments.
2576
2577 <div class="doc_code">
2578 <pre>
2579 call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2580 </pre>
2581 </div></p>
2582
2583<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
2584 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.
2585
2586 <div class="doc_code">
2587 <pre>
2588 %indvar.next = add i64 %indvar, 1, !dbg !21
2589 </pre>
2590 </div></p>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2591</div>
2592
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2593
2594<!-- *********************************************************************** -->
2595<div class="doc_section">
2596 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2597</div>
2598<!-- *********************************************************************** -->
2599
2600<p>LLVM has a number of "magic" global variables that contain data that affect
2601code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2602of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2603section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2604by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2605
2606<!-- ======================================================================= -->
2607<div class="doc_subsection">
2608<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2609</div>
2610
2611<div class="doc_text">
2612
2613<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2614href="#linkage_appending">appending linkage</a>. This array contains a list of
2615pointers to global variables and functions which may optionally have a pointer
2616cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2617
2618<pre>
2619 @X = global i8 4
2620 @Y = global i32 123
2621
2622 @llvm.used = appending global [2 x i8*] [
2623 i8* @X,
2624 i8* bitcast (i32* @Y to i8*)
2625 ], section "llvm.metadata"
2626</pre>
2627
2628<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2629compiler, assembler, and linker are required to treat the symbol as if there is
2630a reference to the global that it cannot see. For example, if a variable has
2631internal linkage and no references other than that from the <tt>@llvm.used</tt>
2632list, it cannot be deleted. This is commonly used to represent references from
2633inline asms and other things the compiler cannot "see", and corresponds to
2634"attribute((used))" in GNU C.</p>
2635
2636<p>On some targets, the code generator must emit a directive to the assembler or
2637object file to prevent the assembler and linker from molesting the symbol.</p>
2638
2639</div>
2640
2641<!-- ======================================================================= -->
2642<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2643<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2644</div>
2645
2646<div class="doc_text">
2647
2648<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2649<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2650touching the symbol. On targets that support it, this allows an intelligent
2651linker to optimize references to the symbol without being impeded as it would be
2652by <tt>@llvm.used</tt>.</p>
2653
2654<p>This is a rare construct that should only be used in rare circumstances, and
2655should not be exposed to source languages.</p>
2656
2657</div>
2658
2659<!-- ======================================================================= -->
2660<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2661<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2662</div>
2663
2664<div class="doc_text">
2665
2666<p>TODO: Describe this.</p>
2667
2668</div>
2669
2670<!-- ======================================================================= -->
2671<div class="doc_subsection">
2672<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2673</div>
2674
2675<div class="doc_text">
2676
2677<p>TODO: Describe this.</p>
2678
2679</div>
2680
2681
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2682<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2683<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2684<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2685
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2686<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2687
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2688<p>The LLVM instruction set consists of several different classifications of
2689 instructions: <a href="#terminators">terminator
2690 instructions</a>, <a href="#binaryops">binary instructions</a>,
2691 <a href="#bitwiseops">bitwise binary instructions</a>,
2692 <a href="#memoryops">memory instructions</a>, and
2693 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2694
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2695</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2696
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2697<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2698<div class="doc_subsection"> <a name="terminators">Terminator
2699Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2700
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2701<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2702
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2703<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2704 in a program ends with a "Terminator" instruction, which indicates which
2705 block should be executed after the current block is finished. These
2706 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2707 control flow, not values (the one exception being the
2708 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2709
2710<p>There are six different terminator instructions: the
2711 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2712 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2713 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2714 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2715 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2716 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2717 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2718
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2719</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2721<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2722<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2723Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2724
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2725<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2727<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2728<pre>
2729 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2730 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2731</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2732
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2733<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2734<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2735 a value) from a function back to the caller.</p>
2736
2737<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2738 value and then causes control flow, and one that just causes control flow to
2739 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2740
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2741<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2742<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2743 return value. The type of the return value must be a
2744 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2745
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2746<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2747 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2748 value or a return value with a type that does not match its type, or if it
2749 has a void return type and contains a '<tt>ret</tt>' instruction with a
2750 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2751
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2752<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2753<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2754 the calling function's context. If the caller is a
2755 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2756 instruction after the call. If the caller was an
2757 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2758 the beginning of the "normal" destination block. If the instruction returns
2759 a value, that value shall set the call or invoke instruction's return
2760 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2761
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2762<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2763<pre>
2764 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2765 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2766 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2767</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2768
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2769</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2770<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2771<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2772
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2773<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2774
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2775<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2776<pre>
2777 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2778</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2780<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2781<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2782 different basic block in the current function. There are two forms of this
2783 instruction, corresponding to a conditional branch and an unconditional
2784 branch.</p>
2785
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2786<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2787<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2788 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2789 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2790 target.</p>
2791
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2792<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2793<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2794 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2795 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2796 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2797
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2798<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2799<pre>
2800Test:
2801 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2802 br i1 %cond, label %IfEqual, label %IfUnequal
2803IfEqual:
2804 <a href="#i_ret">ret</a> i32 1
2805IfUnequal:
2806 <a href="#i_ret">ret</a> i32 0
2807</pre>
2808
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2809</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2810
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2811<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2812<div class="doc_subsubsection">
2813 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2814</div>
2815
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2816<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2817
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2818<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2819<pre>
2820 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2821</pre>
2822
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2823<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2824<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2825 several different places. It is a generalization of the '<tt>br</tt>'
2826 instruction, allowing a branch to occur to one of many possible
2827 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2828
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2829<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2830<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2831 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2832 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2833 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2834
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2835<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2836<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2837 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2838 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2839 transferred to the corresponding destination; otherwise, control flow is
2840 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2841
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2842<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2843<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2844 <tt>switch</tt> instruction, this instruction may be code generated in
2845 different ways. For example, it could be generated as a series of chained
2846 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2847
2848<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2849<pre>
2850 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2851 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2852 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2853
2854 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2855 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2856
2857 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2858 switch i32 %val, label %otherwise [ i32 0, label %onzero
2859 i32 1, label %onone
2860 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2861</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2862
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2863</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2864
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2865
2866<!-- _______________________________________________________________________ -->
2867<div class="doc_subsubsection">
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2868 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2869</div>
2870
2871<div class="doc_text">
2872
2873<h5>Syntax:</h5>
2874<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2875 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2876</pre>
2877
2878<h5>Overview:</h5>
2879
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2880<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2881 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2882 "<tt>address</tt>". Address must be derived from a <a
2883 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2884
2885<h5>Arguments:</h5>
2886
2887<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2888 rest of the arguments indicate the full set of possible destinations that the
2889 address may point to. Blocks are allowed to occur multiple times in the
2890 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2891
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2892<p>This destination list is required so that dataflow analysis has an accurate
2893 understanding of the CFG.</p>
2894
2895<h5>Semantics:</h5>
2896
2897<p>Control transfers to the block specified in the address argument. All
2898 possible destination blocks must be listed in the label list, otherwise this
2899 instruction has undefined behavior. This implies that jumps to labels
2900 defined in other functions have undefined behavior as well.</p>
2901
2902<h5>Implementation:</h5>
2903
2904<p>This is typically implemented with a jump through a register.</p>
2905
2906<h5>Example:</h5>
2907<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2908 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2909</pre>
2910
2911</div>
2912
2913
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2914<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2915<div class="doc_subsubsection">
2916 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2917</div>
2918
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2919<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2920
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2921<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2922<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2923 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]2924 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2925</pre>
2926
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2927<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2928<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2929 function, with the possibility of control flow transfer to either the
2930 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2931 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2932 control flow will return to the "normal" label. If the callee (or any
2933 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2934 instruction, control is interrupted and continued at the dynamically nearest
2935 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2936
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2937<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2938<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2939
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2940<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2941 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2942 convention</a> the call should use. If none is specified, the call
2943 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2944
2945 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2946 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2947 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2948
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2949 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2950 function value being invoked. In most cases, this is a direct function
2951 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2952 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2953
2954 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2955 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2956
2957 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2958 signature argument types and parameter attributes. All arguments must be
2959 of <a href="#t_firstclass">first class</a> type. If the function
2960 signature indicates the function accepts a variable number of arguments,
2961 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2962
2963 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2964 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2965
2966 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2968
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2969 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2970 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2971 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2972</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2973
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2974<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975<p>This instruction is designed to operate as a standard
2976 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2977 primary difference is that it establishes an association with a label, which
2978 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2979
2980<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2981 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2982 exception. Additionally, this is important for implementation of
2983 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2984
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2985<p>For the purposes of the SSA form, the definition of the value returned by the
2986 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2987 block to the "normal" label. If the callee unwinds then no return value is
2988 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2989
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]2990<p>Note that the code generator does not yet completely support unwind, and
2991that the invoke/unwind semantics are likely to change in future versions.</p>
2992
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2993<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2994<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2995 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2996 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2997 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2998 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2999</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3000
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3001</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3002
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3003<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3004
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3005<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
3006Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3007
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3008<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3009
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3010<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3011<pre>
3012 unwind
3013</pre>
3014
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3015<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3016<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3017 at the first callee in the dynamic call stack which used
3018 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3019 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3020
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3021<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3022<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023 immediately halt. The dynamic call stack is then searched for the
3024 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3025 Once found, execution continues at the "exceptional" destination block
3026 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3027 instruction in the dynamic call chain, undefined behavior results.</p>
3028
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3029<p>Note that the code generator does not yet completely support unwind, and
3030that the invoke/unwind semantics are likely to change in future versions.</p>
3031
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3032</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3033
3034<!-- _______________________________________________________________________ -->
3035
3036<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
3037Instruction</a> </div>
3038
3039<div class="doc_text">
3040
3041<h5>Syntax:</h5>
3042<pre>
3043 unreachable
3044</pre>
3045
3046<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3047<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3048 instruction is used to inform the optimizer that a particular portion of the
3049 code is not reachable. This can be used to indicate that the code after a
3050 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3051
3052<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3053<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3054
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3055</div>
3056
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3057<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3058<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3059
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3060<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3061
3062<p>Binary operators are used to do most of the computation in a program. They
3063 require two operands of the same type, execute an operation on them, and
3064 produce a single value. The operands might represent multiple data, as is
3065 the case with the <a href="#t_vector">vector</a> data type. The result value
3066 has the same type as its operands.</p>
3067
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3068<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3069
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3070</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3071
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3072<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3073<div class="doc_subsubsection">
3074 <a name="i_add">'<tt>add</tt>' Instruction</a>
3075</div>
3076
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3077<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3078
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3079<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3080<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3081 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3082 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3083 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3084 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3085</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3086
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3087<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3088<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3089
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3090<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3091<p>The two arguments to the '<tt>add</tt>' instruction must
3092 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3093 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3094
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3095<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3096<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3097
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3098<p>If the sum has unsigned overflow, the result returned is the mathematical
3099 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3100
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3101<p>Because LLVM integers use a two's complement representation, this instruction
3102 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3103
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3104<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3105 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3106 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
3107 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3108
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3109<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3110<pre>
3111 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3112</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3113
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3114</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3115
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3116<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3117<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3118 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3119</div>
3120
3121<div class="doc_text">
3122
3123<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3124<pre>
3125 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3126</pre>
3127
3128<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3129<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3130
3131<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3132<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3133 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3134 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3135
3136<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3137<p>The value produced is the floating point sum of the two operands.</p>
3138
3139<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3140<pre>
3141 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3142</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3143
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3144</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3145
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3146<!-- _______________________________________________________________________ -->
3147<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3148 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3149</div>
3150
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3151<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3152
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3153<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3154<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3155 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3156 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3157 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3158 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3159</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3160
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3161<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3162<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3163 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3164
3165<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3166 '<tt>neg</tt>' instruction present in most other intermediate
3167 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3168
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3169<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3170<p>The two arguments to the '<tt>sub</tt>' instruction must
3171 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3172 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3173
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3174<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3175<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3176
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3177<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3178 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3179 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3180
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3181<p>Because LLVM integers use a two's complement representation, this instruction
3182 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3183
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3184<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3185 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3186 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
3187 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3188
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3189<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3190<pre>
3191 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3192 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3193</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3194
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3195</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3196
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3197<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3198<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3199 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3200</div>
3201
3202<div class="doc_text">
3203
3204<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3205<pre>
3206 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3207</pre>
3208
3209<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3210<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3211 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3212
3213<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3214 '<tt>fneg</tt>' instruction present in most other intermediate
3215 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3216
3217<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3218<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3219 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3220 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3221
3222<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3223<p>The value produced is the floating point difference of the two operands.</p>
3224
3225<h5>Example:</h5>
3226<pre>
3227 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3228 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3229</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3230
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3231</div>
3232
3233<!-- _______________________________________________________________________ -->
3234<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3235 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3236</div>
3237
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3238<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3239
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3240<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3241<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3242 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3243 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3244 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3245 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3246</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3247
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3248<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3249<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3250
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3251<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3252<p>The two arguments to the '<tt>mul</tt>' instruction must
3253 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3254 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3255
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3256<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3257<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3258
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3259<p>If the result of the multiplication has unsigned overflow, the result
3260 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3261 width of the result.</p>
3262
3263<p>Because LLVM integers use a two's complement representation, and the result
3264 is the same width as the operands, this instruction returns the correct
3265 result for both signed and unsigned integers. If a full product
3266 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3267 be sign-extended or zero-extended as appropriate to the width of the full
3268 product.</p>
3269
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3270<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3271 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3272 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3273 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3274
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3275<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3276<pre>
3277 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3278</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3279
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3280</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3281
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3282<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3283<div class="doc_subsubsection">
3284 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3285</div>
3286
3287<div class="doc_text">
3288
3289<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3290<pre>
3291 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3292</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3293
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3294<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3295<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3296
3297<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3298<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3299 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3300 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3301
3302<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3303<p>The value produced is the floating point product of the two operands.</p>
3304
3305<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3306<pre>
3307 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3308</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3309
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3310</div>
3311
3312<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3313<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3314</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3315
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3316<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3317
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3318<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3319<pre>
3320 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3321</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3322
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3323<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3324<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3325
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3326<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3327<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3328 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3329 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3330
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3331<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3332<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3333
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3334<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3335 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3336
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3337<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3338
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3339<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3340<pre>
3341 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3342</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3343
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3344</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3345
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3346<!-- _______________________________________________________________________ -->
3347<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3348</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3349
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3350<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3351
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3352<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3353<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3354 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3355 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3356</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3357
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3358<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3359<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3360
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3361<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3362<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3364 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3365
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3366<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3367<p>The value produced is the signed integer quotient of the two operands rounded
3368 towards zero.</p>
3369
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3370<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3371 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3372
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3373<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374 undefined behavior; this is a rare case, but can occur, for example, by doing
3375 a 32-bit division of -2147483648 by -1.</p>
3376
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3377<p>If the <tt>exact</tt> keyword is present, the result value of the
3378 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3379 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3380
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3381<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3382<pre>
3383 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3384</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3386</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3387
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3388<!-- _______________________________________________________________________ -->
3389<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3390Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3391
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3392<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3394<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3395<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3396 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3397</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3398
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3399<h5>Overview:</h5>
3400<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3401
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3402<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3403<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3404 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3405 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3406
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3407<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3408<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3409
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3410<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3411<pre>
3412 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3413</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3414
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3415</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3416
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3417<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3418<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3419</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3420
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3421<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3422
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3423<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3424<pre>
3425 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3426</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3427
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3428<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3429<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3430 division of its two arguments.</p>
3431
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3432<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3433<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3434 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3435 values. Both arguments must have identical types.</p>
3436
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3437<h5>Semantics:</h5>
3438<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3439 This instruction always performs an unsigned division to get the
3440 remainder.</p>
3441
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3442<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3443 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3444
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3445<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3446
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3447<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3448<pre>
3449 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3450</pre>
3451
3452</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3453
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3454<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3455<div class="doc_subsubsection">
3456 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3457</div>
3458
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3459<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3460
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3461<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3462<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3463 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3464</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3465
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3466<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3467<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3468 division of its two operands. This instruction can also take
3469 <a href="#t_vector">vector</a> versions of the values in which case the
3470 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3471
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3472<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3473<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3474 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3475 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3476
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3477<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3478<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3479 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3480 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3481 a value. For more information about the difference,
3482 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3483 Math Forum</a>. For a table of how this is implemented in various languages,
3484 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3485 Wikipedia: modulo operation</a>.</p>
3486
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3487<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3488 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3489
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3490<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3491 Overflow also leads to undefined behavior; this is a rare case, but can
3492 occur, for example, by taking the remainder of a 32-bit division of
3493 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3494 lets srem be implemented using instructions that return both the result of
3495 the division and the remainder.)</p>
3496
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3497<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3498<pre>
3499 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3500</pre>
3501
3502</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3503
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3504<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3505<div class="doc_subsubsection">
3506 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3507
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3508<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3509
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3510<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3511<pre>
3512 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3513</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3514
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3515<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3516<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3517 its two operands.</p>
3518
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3519<h5>Arguments:</h5>
3520<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3521 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3522 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3523
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3524<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3525<p>This instruction returns the <i>remainder</i> of a division. The remainder
3526 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3527
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3528<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3529<pre>
3530 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3531</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3533</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3534
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3535<!-- ======================================================================= -->
3536<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3537Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3538
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3539<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3540
3541<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3542 program. They are generally very efficient instructions and can commonly be
3543 strength reduced from other instructions. They require two operands of the
3544 same type, execute an operation on them, and produce a single value. The
3545 resulting value is the same type as its operands.</p>
3546
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3547</div>
3548
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3549<!-- _______________________________________________________________________ -->
3550<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3551Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3552
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3553<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3554
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3555<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3556<pre>
3557 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3558</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3559
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3560<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3561<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3562 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3563
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3564<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3565<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3566 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3567 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3568
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3569<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3570<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3571 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3572 is (statically or dynamically) negative or equal to or larger than the number
3573 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3574 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3575 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3576
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3577<h5>Example:</h5>
3578<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3579 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3580 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3581 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3582 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3583 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3584</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3585
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3586</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3587
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3588<!-- _______________________________________________________________________ -->
3589<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3590Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3591
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3592<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3593
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3594<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3595<pre>
3596 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3597</pre>
3598
3599<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3601 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3602
3603<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3604<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3605 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3606 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3607
3608<h5>Semantics:</h5>
3609<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610 significant bits of the result will be filled with zero bits after the shift.
3611 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3612 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3613 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3614 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3615
3616<h5>Example:</h5>
3617<pre>
3618 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3619 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3620 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3621 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3622 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3623 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3624</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3625
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3626</div>
3627
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3628<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3629<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3630Instruction</a> </div>
3631<div class="doc_text">
3632
3633<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3634<pre>
3635 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3636</pre>
3637
3638<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3639<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3640 operand shifted to the right a specified number of bits with sign
3641 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3642
3643<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3644<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3645 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3646 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3647
3648<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3649<p>This instruction always performs an arithmetic shift right operation, The
3650 most significant bits of the result will be filled with the sign bit
3651 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3652 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3653 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3654 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3655
3656<h5>Example:</h5>
3657<pre>
3658 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3659 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3660 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3661 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3662 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3663 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3664</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3665
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3666</div>
3667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3668<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3669<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3670Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3671
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3672<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3673
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3674<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3675<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3676 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3677</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3678
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3679<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3681 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3682
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3683<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3684<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3685 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3686 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3687
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3688<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3689<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3690
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3691<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3692 <tbody>
3693 <tr>
3694 <td>In0</td>
3695 <td>In1</td>
3696 <td>Out</td>
3697 </tr>
3698 <tr>
3699 <td>0</td>
3700 <td>0</td>
3701 <td>0</td>
3702 </tr>
3703 <tr>
3704 <td>0</td>
3705 <td>1</td>
3706 <td>0</td>
3707 </tr>
3708 <tr>
3709 <td>1</td>
3710 <td>0</td>
3711 <td>0</td>
3712 </tr>
3713 <tr>
3714 <td>1</td>
3715 <td>1</td>
3716 <td>1</td>
3717 </tr>
3718 </tbody>
3719</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3721<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3722<pre>
3723 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3724 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3725 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3726</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3727</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3728<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3729<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3730
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3731<div class="doc_text">
3732
3733<h5>Syntax:</h5>
3734<pre>
3735 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3736</pre>
3737
3738<h5>Overview:</h5>
3739<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3740 two operands.</p>
3741
3742<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3743<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3744 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3745 values. Both arguments must have identical types.</p>
3746
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3747<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3748<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3749
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3750<table border="1" cellspacing="0" cellpadding="4">
3751 <tbody>
3752 <tr>
3753 <td>In0</td>
3754 <td>In1</td>
3755 <td>Out</td>
3756 </tr>
3757 <tr>
3758 <td>0</td>
3759 <td>0</td>
3760 <td>0</td>
3761 </tr>
3762 <tr>
3763 <td>0</td>
3764 <td>1</td>
3765 <td>1</td>
3766 </tr>
3767 <tr>
3768 <td>1</td>
3769 <td>0</td>
3770 <td>1</td>
3771 </tr>
3772 <tr>
3773 <td>1</td>
3774 <td>1</td>
3775 <td>1</td>
3776 </tr>
3777 </tbody>
3778</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3780<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3781<pre>
3782 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3783 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3784 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3785</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3786
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3787</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3789<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3790<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3791Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3792
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3793<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3794
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3795<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3796<pre>
3797 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3798</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3799
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3800<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3801<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3802 its two operands. The <tt>xor</tt> is used to implement the "one's
3803 complement" operation, which is the "~" operator in C.</p>
3804
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3805<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3806<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3807 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3808 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3809
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3810<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3811<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3812
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3813<table border="1" cellspacing="0" cellpadding="4">
3814 <tbody>
3815 <tr>
3816 <td>In0</td>
3817 <td>In1</td>
3818 <td>Out</td>
3819 </tr>
3820 <tr>
3821 <td>0</td>
3822 <td>0</td>
3823 <td>0</td>
3824 </tr>
3825 <tr>
3826 <td>0</td>
3827 <td>1</td>
3828 <td>1</td>
3829 </tr>
3830 <tr>
3831 <td>1</td>
3832 <td>0</td>
3833 <td>1</td>
3834 </tr>
3835 <tr>
3836 <td>1</td>
3837 <td>1</td>
3838 <td>0</td>
3839 </tr>
3840 </tbody>
3841</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3842
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3843<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3844<pre>
3845 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3846 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3847 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3848 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3849</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3850
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3851</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3852
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3853<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3854<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3855 <a name="vectorops">Vector Operations</a>
3856</div>
3857
3858<div class="doc_text">
3859
3860<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3861 target-independent manner. These instructions cover the element-access and
3862 vector-specific operations needed to process vectors effectively. While LLVM
3863 does directly support these vector operations, many sophisticated algorithms
3864 will want to use target-specific intrinsics to take full advantage of a
3865 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3866
3867</div>
3868
3869<!-- _______________________________________________________________________ -->
3870<div class="doc_subsubsection">
3871 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3872</div>
3873
3874<div class="doc_text">
3875
3876<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3877<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3878 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3879</pre>
3880
3881<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3882<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3883 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3884
3885
3886<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3887<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3888 of <a href="#t_vector">vector</a> type. The second operand is an index
3889 indicating the position from which to extract the element. The index may be
3890 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3891
3892<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3893<p>The result is a scalar of the same type as the element type of
3894 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3895 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3896 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3897
3898<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3899<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3900 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3901</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3902
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3903</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3904
3905<!-- _______________________________________________________________________ -->
3906<div class="doc_subsubsection">
3907 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3908</div>
3909
3910<div class="doc_text">
3911
3912<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3913<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3914 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3915</pre>
3916
3917<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3918<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3919 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3920
3921<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3922<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3923 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3924 whose type must equal the element type of the first operand. The third
3925 operand is an index indicating the position at which to insert the value.
3926 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3927
3928<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3929<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3930 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3931 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3932 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3933
3934<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3935<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3936 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3937</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3938
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3939</div>
3940
3941<!-- _______________________________________________________________________ -->
3942<div class="doc_subsubsection">
3943 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3944</div>
3945
3946<div class="doc_text">
3947
3948<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3949<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3950 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3951</pre>
3952
3953<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3954<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3955 from two input vectors, returning a vector with the same element type as the
3956 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3957
3958<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3959<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3960 with types that match each other. The third argument is a shuffle mask whose
3961 element type is always 'i32'. The result of the instruction is a vector
3962 whose length is the same as the shuffle mask and whose element type is the
3963 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3964
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3965<p>The shuffle mask operand is required to be a constant vector with either
3966 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3967
3968<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3969<p>The elements of the two input vectors are numbered from left to right across
3970 both of the vectors. The shuffle mask operand specifies, for each element of
3971 the result vector, which element of the two input vectors the result element
3972 gets. The element selector may be undef (meaning "don't care") and the
3973 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3974
3975<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3976<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3977 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3978 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3979 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3980 &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.
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3981 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3982 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3983 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3984 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3985</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3986
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3987</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3988
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3989<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3990<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3991 <a name="aggregateops">Aggregate Operations</a>
3992</div>
3993
3994<div class="doc_text">
3995
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]3996<p>LLVM supports several instructions for working with
3997 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3998
3999</div>
4000
4001<!-- _______________________________________________________________________ -->
4002<div class="doc_subsubsection">
4003 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
4004</div>
4005
4006<div class="doc_text">
4007
4008<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4009<pre>
4010 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4011</pre>
4012
4013<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4014<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4015 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4016
4017<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4018<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4019 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4020 <a href="#t_array">array</a> type. The operands are constant indices to
4021 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4022 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4023
4024<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4025<p>The result is the value at the position in the aggregate specified by the
4026 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4027
4028<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4029<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4030 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4031</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4032
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4033</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4034
4035<!-- _______________________________________________________________________ -->
4036<div class="doc_subsubsection">
4037 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
4038</div>
4039
4040<div class="doc_text">
4041
4042<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4043<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4044 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt; <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4045</pre>
4046
4047<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4048<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4049 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4050
4051<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4052<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4053 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4054 <a href="#t_array">array</a> type. The second operand is a first-class
4055 value to insert. The following operands are constant indices indicating
4056 the position at which to insert the value in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4057 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
4058 value to insert must have the same type as the value identified by the
4059 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4060
4061<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4062<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4063 that of <tt>val</tt> except that the value at the position specified by the
4064 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4065
4066<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4067<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4068 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4069 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4070</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4071
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4072</div>
4073
4074
4075<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4076<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4077 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4078</div>
4079
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4080<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4081
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4082<p>A key design point of an SSA-based representation is how it represents
4083 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4084 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4085 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4086
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4087</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4088
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4089<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4090<div class="doc_subsubsection">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4091 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4092</div>
4093
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4094<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4095
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4096<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4097<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4098 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4099</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4100
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4101<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4102<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4103 currently executing function, to be automatically released when this function
4104 returns to its caller. The object is always allocated in the generic address
4105 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4106
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4107<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4108<p>The '<tt>alloca</tt>' instruction
4109 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4110 runtime stack, returning a pointer of the appropriate type to the program.
4111 If "NumElements" is specified, it is the number of elements allocated,
4112 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4113 specified, the value result of the allocation is guaranteed to be aligned to
4114 at least that boundary. If not specified, or if zero, the target can choose
4115 to align the allocation on any convenient boundary compatible with the
4116 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4117
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4118<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4119
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4120<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4121<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4122 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4123 memory is automatically released when the function returns. The
4124 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4125 variables that must have an address available. When the function returns
4126 (either with the <tt><a href="#i_ret">ret</a></tt>
4127 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4128 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4129
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4130<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4131<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4132 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4133 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4134 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4135 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4136</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4137
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4138</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4139
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4140<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4141<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4142Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4143
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4144<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4145
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4146<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4148 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4149 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4150 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4151</pre>
4152
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4153<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4154<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4155
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4156<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4157<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4158 from which to load. The pointer must point to
4159 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4160 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4161 number or order of execution of this <tt>load</tt> with other
4162 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4163 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4164
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4165<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4166 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4167 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4168 alignment for the target. It is the responsibility of the code emitter to
4169 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4170 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4171 produce less efficient code. An alignment of 1 is always safe.</p>
4172
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4173<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4174 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4175 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4176 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4177 and code generator that this load is not expected to be reused in the cache.
4178 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4179 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4180
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4181<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4182<p>The location of memory pointed to is loaded. If the value being loaded is of
4183 scalar type then the number of bytes read does not exceed the minimum number
4184 of bytes needed to hold all bits of the type. For example, loading an
4185 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4186 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4187 is undefined if the value was not originally written using a store of the
4188 same type.</p>
4189
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4190<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4191<pre>
4192 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4193 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4194 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4195</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4196
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4197</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4198
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4199<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4200<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4201Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4202
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]4203<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4204
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4205<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4206<pre>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4207 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4208 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4209</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4210
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4211<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4212<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4213
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4214<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4215<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4216 and an address at which to store it. The type of the
4217 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4218 the <a href="#t_firstclass">first class</a> type of the
4219 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4220 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4221 or order of execution of this <tt>store</tt> with other
4222 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4223 instructions.</p>
4224
4225<p>The optional constant "align" argument specifies the alignment of the
4226 operation (that is, the alignment of the memory address). A value of 0 or an
4227 omitted "align" argument means that the operation has the preferential
4228 alignment for the target. It is the responsibility of the code emitter to
4229 ensure that the alignment information is correct. Overestimating the
4230 alignment results in an undefined behavior. Underestimating the alignment may
4231 produce less efficient code. An alignment of 1 is always safe.</p>
4232
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4233<p>The optional !nontemporal metadata must reference a single metatadata
4234 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4235 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4236 instruction tells the optimizer and code generator that this load is
4237 not expected to be reused in the cache. The code generator may
4238 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4239 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4240
4241
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4242<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4244 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4245 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4246 does not exceed the minimum number of bytes needed to hold all bits of the
4247 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4248 writing a value of a type like <tt>i20</tt> with a size that is not an
4249 integral number of bytes, it is unspecified what happens to the extra bits
4250 that do not belong to the type, but they will typically be overwritten.</p>
4251
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4252<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4253<pre>
4254 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4255 store i32 3, i32* %ptr <i>; yields {void}</i>
4256 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4257</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4258
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4259</div>
4260
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4261<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4262<div class="doc_subsubsection">
4263 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4264</div>
4265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4266<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4267
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4268<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4269<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4270 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4271 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4272</pre>
4273
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4274<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4275<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4276 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4277 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4278
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4279<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4280<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4281 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4282 elements of the aggregate object are indexed. The interpretation of each
4283 index is dependent on the type being indexed into. The first index always
4284 indexes the pointer value given as the first argument, the second index
4285 indexes a value of the type pointed to (not necessarily the value directly
4286 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4287 indexed into must be a pointer value, subsequent types can be arrays,
4288 vectors, structs and unions. Note that subsequent types being indexed into
4289 can never be pointers, since that would require loading the pointer before
4290 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4291
4292<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4293 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4294 integer <b>constants</b> are allowed. When indexing into an array, pointer
4295 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4296 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4297
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4298<p>For example, let's consider a C code fragment and how it gets compiled to
4299 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4300
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4301<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4302<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4303struct RT {
4304 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4305 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4306 char C;
4307};
4308struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4309 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4310 double Y;
4311 struct RT Z;
4312};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4313
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4314int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4315 return &amp;s[1].Z.B[5][13];
4316}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4317</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4318</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4319
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4320<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4321
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4322<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4323<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4324%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4325%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4326
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4327define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4328entry:
4329 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4330 ret i32* %reg
4331}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4332</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4333</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4334
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4335<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4336<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4337 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4338 }</tt>' type, a structure. The second index indexes into the third element
4339 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4340 i8 }</tt>' type, another structure. The third index indexes into the second
4341 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4342 array. The two dimensions of the array are subscripted into, yielding an
4343 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4344 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4345
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4346<p>Note that it is perfectly legal to index partially through a structure,
4347 returning a pointer to an inner element. Because of this, the LLVM code for
4348 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4349
4350<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4351 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4352 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4353 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4354 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4355 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4356 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4357 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4358 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4359</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4360
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4361<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4362 <tt>getelementptr</tt> is undefined if the base pointer is not an
4363 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4364 that would be formed by successive addition of the offsets implied by the
4365 indices to the base address with infinitely precise arithmetic are not an
4366 <i>in bounds</i> address of that allocated object.
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4367 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4368 that point into the object, plus the address one byte past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4369
4370<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4371 the base address with silently-wrapping two's complement arithmetic, and
4372 the result value of the <tt>getelementptr</tt> may be outside the object
4373 pointed to by the base pointer. The result value may not necessarily be
4374 used to access memory though, even if it happens to point into allocated
4375 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4376 section for more information.</p>
4377
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4378<p>The getelementptr instruction is often confusing. For some more insight into
4379 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4380
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4381<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4382<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4383 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4384 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4385 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4386 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4387 <i>; yields i8*:eptr</i>
4388 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4389 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4390 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4391</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4392
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4393</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4394
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4395<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4396<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4397</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4398
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4399<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4400
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4401<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4402 which all take a single operand and a type. They perform various bit
4403 conversions on the operand.</p>
4404
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4405</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4406
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4407<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4408<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4409 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4410</div>
4411<div class="doc_text">
4412
4413<h5>Syntax:</h5>
4414<pre>
4415 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4416</pre>
4417
4418<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4419<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4420 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4421
4422<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4423<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4424 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4425 size and type of the result, which must be
4426 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4427 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4428 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4429
4430<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4431<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4432 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4433 source size must be larger than the destination size, <tt>trunc</tt> cannot
4434 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4435
4436<h5>Example:</h5>
4437<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4438 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4439 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4440 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4441</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4442
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4443</div>
4444
4445<!-- _______________________________________________________________________ -->
4446<div class="doc_subsubsection">
4447 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4448</div>
4449<div class="doc_text">
4450
4451<h5>Syntax:</h5>
4452<pre>
4453 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4454</pre>
4455
4456<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4457<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4458 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4459
4460
4461<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4462<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4463 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4464 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4465 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4466 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4467
4468<h5>Semantics:</h5>
4469<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4470 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4471
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4472<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4473
4474<h5>Example:</h5>
4475<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4476 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4477 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4478</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4479
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4480</div>
4481
4482<!-- _______________________________________________________________________ -->
4483<div class="doc_subsubsection">
4484 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4485</div>
4486<div class="doc_text">
4487
4488<h5>Syntax:</h5>
4489<pre>
4490 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4491</pre>
4492
4493<h5>Overview:</h5>
4494<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4495
4496<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4497<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4499 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4500 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4501 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4502
4503<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4504<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4505 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4506 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4507
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4508<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4509
4510<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4511<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4512 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4513 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4514</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4515
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4516</div>
4517
4518<!-- _______________________________________________________________________ -->
4519<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4520 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4521</div>
4522
4523<div class="doc_text">
4524
4525<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4526<pre>
4527 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4528</pre>
4529
4530<h5>Overview:</h5>
4531<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4532 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4533
4534<h5>Arguments:</h5>
4535<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4536 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4537 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4538 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4539 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4540
4541<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4542<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4543 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4544 <a href="#t_floating">floating point</a> type. If the value cannot fit
4545 within the destination type, <tt>ty2</tt>, then the results are
4546 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4547
4548<h5>Example:</h5>
4549<pre>
4550 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4551 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4552</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4553
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4554</div>
4555
4556<!-- _______________________________________________________________________ -->
4557<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4558 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4559</div>
4560<div class="doc_text">
4561
4562<h5>Syntax:</h5>
4563<pre>
4564 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4565</pre>
4566
4567<h5>Overview:</h5>
4568<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4570
4571<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4572<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4573 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4574 a <a href="#t_floating">floating point</a> type to cast it to. The source
4575 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4576
4577<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4578<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4579 <a href="#t_floating">floating point</a> type to a larger
4580 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4581 used to make a <i>no-op cast</i> because it always changes bits. Use
4582 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4583
4584<h5>Example:</h5>
4585<pre>
4586 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4587 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4588</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4589
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4590</div>
4591
4592<!-- _______________________________________________________________________ -->
4593<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4594 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4595</div>
4596<div class="doc_text">
4597
4598<h5>Syntax:</h5>
4599<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4600 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4601</pre>
4602
4603<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4604<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4605 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4606
4607<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4608<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4609 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4610 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4611 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4612 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4613
4614<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4615<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4616 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4617 towards zero) unsigned integer value. If the value cannot fit
4618 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4619
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4620<h5>Example:</h5>
4621<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4622 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4623 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4624 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4625</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4627</div>
4628
4629<!-- _______________________________________________________________________ -->
4630<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4631 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4632</div>
4633<div class="doc_text">
4634
4635<h5>Syntax:</h5>
4636<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4637 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4638</pre>
4639
4640<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4641<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4642 <a href="#t_floating">floating point</a> <tt>value</tt> to
4643 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4644
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4645<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4646<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4647 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4648 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4649 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4650 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4651
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4652<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4653<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4654 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4655 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4656 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4657
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4658<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4659<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4660 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4661 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4662 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4663</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4664
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4665</div>
4666
4667<!-- _______________________________________________________________________ -->
4668<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4669 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4670</div>
4671<div class="doc_text">
4672
4673<h5>Syntax:</h5>
4674<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4675 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4676</pre>
4677
4678<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4679<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4680 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4681
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4682<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4683<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4684 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4685 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4686 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4687 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4688
4689<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4690<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4691 integer quantity and converts it to the corresponding floating point
4692 value. If the value cannot fit in the floating point value, the results are
4693 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4694
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4695<h5>Example:</h5>
4696<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4697 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4698 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4699</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4700
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4701</div>
4702
4703<!-- _______________________________________________________________________ -->
4704<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4705 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4706</div>
4707<div class="doc_text">
4708
4709<h5>Syntax:</h5>
4710<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4711 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4712</pre>
4713
4714<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4715<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4716 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4717
4718<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4719<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4720 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4721 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4722 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4723 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4724
4725<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4726<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4727 quantity and converts it to the corresponding floating point value. If the
4728 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4729
4730<h5>Example:</h5>
4731<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4732 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4733 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4734</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4735
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4736</div>
4737
4738<!-- _______________________________________________________________________ -->
4739<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4740 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4741</div>
4742<div class="doc_text">
4743
4744<h5>Syntax:</h5>
4745<pre>
4746 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4747</pre>
4748
4749<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4750<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4751 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4752
4753<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4754<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4755 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4756 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4757
4758<h5>Semantics:</h5>
4759<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4760 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4761 truncating or zero extending that value to the size of the integer type. If
4762 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4763 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4764 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4765 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4766
4767<h5>Example:</h5>
4768<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4769 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4770 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4771</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4772
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4773</div>
4774
4775<!-- _______________________________________________________________________ -->
4776<div class="doc_subsubsection">
4777 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4778</div>
4779<div class="doc_text">
4780
4781<h5>Syntax:</h5>
4782<pre>
4783 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4784</pre>
4785
4786<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4787<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4788 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4789
4790<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4791<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4792 value to cast, and a type to cast it to, which must be a
4793 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4794
4795<h5>Semantics:</h5>
4796<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4797 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4798 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4799 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4800 than the size of a pointer then a zero extension is done. If they are the
4801 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4802
4803<h5>Example:</h5>
4804<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4805 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4806 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4807 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4808</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4809
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4810</div>
4811
4812<!-- _______________________________________________________________________ -->
4813<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4814 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4815</div>
4816<div class="doc_text">
4817
4818<h5>Syntax:</h5>
4819<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4820 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4821</pre>
4822
4823<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4824<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4825 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4826
4827<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4828<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4829 non-aggregate first class value, and a type to cast it to, which must also be
4830 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4831 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4832 identical. If the source type is a pointer, the destination type must also be
4833 a pointer. This instruction supports bitwise conversion of vectors to
4834 integers and to vectors of other types (as long as they have the same
4835 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4836
4837<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4838<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4839 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4840 this conversion. The conversion is done as if the <tt>value</tt> had been
4841 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4842 be converted to other pointer types with this instruction. To convert
4843 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4844 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4845
4846<h5>Example:</h5>
4847<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4848 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4849 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4850 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4851</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4852
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4853</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4854
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4855<!-- ======================================================================= -->
4856<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4857
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4858<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4859
4860<p>The instructions in this category are the "miscellaneous" instructions, which
4861 defy better classification.</p>
4862
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4863</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4864
4865<!-- _______________________________________________________________________ -->
4866<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4867</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4868
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4869<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4870
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4871<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4872<pre>
4873 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4874</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4875
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4876<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4877<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4878 boolean values based on comparison of its two integer, integer vector, or
4879 pointer operands.</p>
4880
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4881<h5>Arguments:</h5>
4882<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4883 the condition code indicating the kind of comparison to perform. It is not a
4884 value, just a keyword. The possible condition code are:</p>
4885
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4886<ol>
4887 <li><tt>eq</tt>: equal</li>
4888 <li><tt>ne</tt>: not equal </li>
4889 <li><tt>ugt</tt>: unsigned greater than</li>
4890 <li><tt>uge</tt>: unsigned greater or equal</li>
4891 <li><tt>ult</tt>: unsigned less than</li>
4892 <li><tt>ule</tt>: unsigned less or equal</li>
4893 <li><tt>sgt</tt>: signed greater than</li>
4894 <li><tt>sge</tt>: signed greater or equal</li>
4895 <li><tt>slt</tt>: signed less than</li>
4896 <li><tt>sle</tt>: signed less or equal</li>
4897</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4898
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4899<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4900 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4901 typed. They must also be identical types.</p>
4902
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4903<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4904<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4905 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4906 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4907 result, as follows:</p>
4908
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4909<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4910 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4911 <tt>false</tt> otherwise. No sign interpretation is necessary or
4912 performed.</li>
4913
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4914 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4915 <tt>false</tt> otherwise. No sign interpretation is necessary or
4916 performed.</li>
4917
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4918 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4919 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4920
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4921 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4922 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4923 to <tt>op2</tt>.</li>
4924
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4925 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4926 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4927
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4928 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4929 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4930
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4931 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4932 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4933
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4934 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4935 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4936 to <tt>op2</tt>.</li>
4937
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4938 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4939 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4940
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4941 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4942 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4943</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4944
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4945<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4946 values are compared as if they were integers.</p>
4947
4948<p>If the operands are integer vectors, then they are compared element by
4949 element. The result is an <tt>i1</tt> vector with the same number of elements
4950 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4951
4952<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4953<pre>
4954 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4955 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4956 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4957 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4958 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4959 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4960</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4961
4962<p>Note that the code generator does not yet support vector types with
4963 the <tt>icmp</tt> instruction.</p>
4964
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4965</div>
4966
4967<!-- _______________________________________________________________________ -->
4968<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4969</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4970
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4971<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4972
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4973<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4974<pre>
4975 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4976</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4977
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4978<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4979<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4980 values based on comparison of its operands.</p>
4981
4982<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4983(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4984
4985<p>If the operands are floating point vectors, then the result type is a vector
4986 of boolean with the same number of elements as the operands being
4987 compared.</p>
4988
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4989<h5>Arguments:</h5>
4990<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4991 the condition code indicating the kind of comparison to perform. It is not a
4992 value, just a keyword. The possible condition code are:</p>
4993
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4994<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4995 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4996 <li><tt>oeq</tt>: ordered and equal</li>
4997 <li><tt>ogt</tt>: ordered and greater than </li>
4998 <li><tt>oge</tt>: ordered and greater than or equal</li>
4999 <li><tt>olt</tt>: ordered and less than </li>
5000 <li><tt>ole</tt>: ordered and less than or equal</li>
5001 <li><tt>one</tt>: ordered and not equal</li>
5002 <li><tt>ord</tt>: ordered (no nans)</li>
5003 <li><tt>ueq</tt>: unordered or equal</li>
5004 <li><tt>ugt</tt>: unordered or greater than </li>
5005 <li><tt>uge</tt>: unordered or greater than or equal</li>
5006 <li><tt>ult</tt>: unordered or less than </li>
5007 <li><tt>ule</tt>: unordered or less than or equal</li>
5008 <li><tt>une</tt>: unordered or not equal</li>
5009 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5010 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5011</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5012
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5013<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5014 <i>unordered</i> means that either operand may be a QNAN.</p>
5015
5016<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5017 a <a href="#t_floating">floating point</a> type or
5018 a <a href="#t_vector">vector</a> of floating point type. They must have
5019 identical types.</p>
5020
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5021<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5022<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5023 according to the condition code given as <tt>cond</tt>. If the operands are
5024 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5025 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5026 follows:</p>
5027
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5028<ol>
5029 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5030
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5031 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5032 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5033
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5034 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5035 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5036
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5037 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5038 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5039
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5040 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5041 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5042
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5043 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5044 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5045
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5046 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5047 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5048
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5049 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5050
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5051 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5052 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5053
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5054 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5055 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5056
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5057 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5058 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5059
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5060 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5061 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5062
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5063 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5064 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5065
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5066 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5067 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5068
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5069 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5070
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5071 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5072</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5073
5074<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5075<pre>
5076 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5077 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5078 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5079 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5080</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5081
5082<p>Note that the code generator does not yet support vector types with
5083 the <tt>fcmp</tt> instruction.</p>
5084
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5085</div>
5086
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5087<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]5088<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5089 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5090</div>
5091
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5092<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5093
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5094<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5095<pre>
5096 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5097</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5098
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5099<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5100<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5101 SSA graph representing the function.</p>
5102
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5103<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5104<p>The type of the incoming values is specified with the first type field. After
5105 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5106 one pair for each predecessor basic block of the current block. Only values
5107 of <a href="#t_firstclass">first class</a> type may be used as the value
5108 arguments to the PHI node. Only labels may be used as the label
5109 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5110
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5111<p>There must be no non-phi instructions between the start of a basic block and
5112 the PHI instructions: i.e. PHI instructions must be first in a basic
5113 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5114
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5115<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5116 occur on the edge from the corresponding predecessor block to the current
5117 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5118 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5119
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5120<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5121<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5122 specified by the pair corresponding to the predecessor basic block that
5123 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5124
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5125<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5126<pre>
5127Loop: ; Infinite loop that counts from 0 on up...
5128 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5129 %nextindvar = add i32 %indvar, 1
5130 br label %Loop
5131</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5132
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5133</div>
5134
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5135<!-- _______________________________________________________________________ -->
5136<div class="doc_subsubsection">
5137 <a name="i_select">'<tt>select</tt>' Instruction</a>
5138</div>
5139
5140<div class="doc_text">
5141
5142<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5143<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5144 &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>
5145
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5146 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5147</pre>
5148
5149<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5150<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5151 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5152
5153
5154<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5155<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5156 values indicating the condition, and two values of the
5157 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5158 vectors and the condition is a scalar, then entire vectors are selected, not
5159 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5160
5161<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5162<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5163 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5164
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5165<p>If the condition is a vector of i1, then the value arguments must be vectors
5166 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5167
5168<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5169<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5170 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5171</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5172
5173<p>Note that the code generator does not yet support conditions
5174 with vector type.</p>
5175
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5176</div>
5177
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5178<!-- _______________________________________________________________________ -->
5179<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5180 <a name="i_call">'<tt>call</tt>' Instruction</a>
5181</div>
5182
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5183<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5184
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5185<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5186<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5187 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5188</pre>
5189
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5190<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5191<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5192
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5193<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5194<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5195
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5196<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5197 <li>The optional "tail" marker indicates that the callee function does not
5198 access any allocas or varargs in the caller. Note that calls may be
5199 marked "tail" even if they do not occur before
5200 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5201 present, the function call is eligible for tail call optimization,
5202 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5203 optimized into a jump</a>. The code generator may optimize calls marked
5204 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5205 sibling call optimization</a> when the caller and callee have
5206 matching signatures, or 2) forced tail call optimization when the
5207 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5208 <ul>
5209 <li>Caller and callee both have the calling
5210 convention <tt>fastcc</tt>.</li>
5211 <li>The call is in tail position (ret immediately follows call and ret
5212 uses value of call or is void).</li>
5213 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5214 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5215 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5216 constraints are met.</a></li>
5217 </ul>
5218 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5219
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5220 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5221 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5222 defaults to using C calling conventions. The calling convention of the
5223 call must match the calling convention of the target function, or else the
5224 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5225
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5227 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5228 '<tt>inreg</tt>' attributes are valid here.</li>
5229
5230 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5231 type of the return value. Functions that return no value are marked
5232 <tt><a href="#t_void">void</a></tt>.</li>
5233
5234 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5235 being invoked. The argument types must match the types implied by this
5236 signature. This type can be omitted if the function is not varargs and if
5237 the function type does not return a pointer to a function.</li>
5238
5239 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5240 be invoked. In most cases, this is a direct function invocation, but
5241 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5242 to function value.</li>
5243
5244 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5245 signature argument types and parameter attributes. All arguments must be
5246 of <a href="#t_firstclass">first class</a> type. If the function
5247 signature indicates the function accepts a variable number of arguments,
5248 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5249
5250 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5251 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5252 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5253</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5254
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5255<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5257 a specified function, with its incoming arguments bound to the specified
5258 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5259 function, control flow continues with the instruction after the function
5260 call, and the return value of the function is bound to the result
5261 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5263<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5264<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5265 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5266 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5267 %X = tail call i32 @foo() <i>; yields i32</i>
5268 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5269 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5270
5271 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5272 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5273 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5274 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5275 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5276 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5277</pre>
5278
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5279<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5280standard C99 library as being the C99 library functions, and may perform
5281optimizations or generate code for them under that assumption. This is
5282something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5283freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5284
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5285</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5286
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5287<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5288<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5289 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5290</div>
5291
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5292<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5293
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5294<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5295<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5296 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5297</pre>
5298
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5299<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5300<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5301 the "variable argument" area of a function call. It is used to implement the
5302 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5303
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5304<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5305<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5306 argument. It returns a value of the specified argument type and increments
5307 the <tt>va_list</tt> to point to the next argument. The actual type
5308 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5309
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5310<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5311<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5312 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5313 to the next argument. For more information, see the variable argument
5314 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5315
5316<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5317 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5318 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5319
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5320<p><tt>va_arg</tt> is an LLVM instruction instead of
5321 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5322 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5323
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5324<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5325<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5326
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5327<p>Note that the code generator does not yet fully support va_arg on many
5328 targets. Also, it does not currently support va_arg with aggregate types on
5329 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5331</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5332
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5333<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5334<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5335<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5336
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5337<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5338
5339<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5340 well known names and semantics and are required to follow certain
5341 restrictions. Overall, these intrinsics represent an extension mechanism for
5342 the LLVM language that does not require changing all of the transformations
5343 in LLVM when adding to the language (or the bitcode reader/writer, the
5344 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5345
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5346<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5347 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5348 begin with this prefix. Intrinsic functions must always be external
5349 functions: you cannot define the body of intrinsic functions. Intrinsic
5350 functions may only be used in call or invoke instructions: it is illegal to
5351 take the address of an intrinsic function. Additionally, because intrinsic
5352 functions are part of the LLVM language, it is required if any are added that
5353 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5354
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5355<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5356 family of functions that perform the same operation but on different data
5357 types. Because LLVM can represent over 8 million different integer types,
5358 overloading is used commonly to allow an intrinsic function to operate on any
5359 integer type. One or more of the argument types or the result type can be
5360 overloaded to accept any integer type. Argument types may also be defined as
5361 exactly matching a previous argument's type or the result type. This allows
5362 an intrinsic function which accepts multiple arguments, but needs all of them
5363 to be of the same type, to only be overloaded with respect to a single
5364 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5365
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5366<p>Overloaded intrinsics will have the names of its overloaded argument types
5367 encoded into its function name, each preceded by a period. Only those types
5368 which are overloaded result in a name suffix. Arguments whose type is matched
5369 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5370 can take an integer of any width and returns an integer of exactly the same
5371 integer width. This leads to a family of functions such as
5372 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5373 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5374 suffix is required. Because the argument's type is matched against the return
5375 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5376
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5377<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5378 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5380</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5381
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5382<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5383<div class="doc_subsection">
5384 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5385</div>
5386
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5387<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5388
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5389<p>Variable argument support is defined in LLVM with
5390 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5391 intrinsic functions. These functions are related to the similarly named
5392 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5393
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5394<p>All of these functions operate on arguments that use a target-specific value
5395 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5396 not define what this type is, so all transformations should be prepared to
5397 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5398
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5399<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5400 instruction and the variable argument handling intrinsic functions are
5401 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5402
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5403<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5404<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5405define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5406 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5407 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5408 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5409 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5410
5411 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5412 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5413
5414 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5415 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5416 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5417 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5418 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5419
5420 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5421 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5422 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5423}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5424
5425declare void @llvm.va_start(i8*)
5426declare void @llvm.va_copy(i8*, i8*)
5427declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5428</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5429</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5430
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5431</div>
5432
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5433<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5434<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5435 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5436</div>
5437
5438
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5439<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5440
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5441<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5442<pre>
5443 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5444</pre>
5445
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5446<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5447<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5448 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5449
5450<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5451<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5452
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5453<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5454<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5455 macro available in C. In a target-dependent way, it initializes
5456 the <tt>va_list</tt> element to which the argument points, so that the next
5457 call to <tt>va_arg</tt> will produce the first variable argument passed to
5458 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5459 need to know the last argument of the function as the compiler can figure
5460 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5461
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5462</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5463
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5464<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5465<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5466 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5467</div>
5468
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5469<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5470
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5471<h5>Syntax:</h5>
5472<pre>
5473 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5474</pre>
5475
5476<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5477<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5478 which has been initialized previously
5479 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5480 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5481
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5482<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5483<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5484
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5485<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5486<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5487 macro available in C. In a target-dependent way, it destroys
5488 the <tt>va_list</tt> element to which the argument points. Calls
5489 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5490 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5491 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5492
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5493</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5494
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5495<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5496<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5497 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5498</div>
5499
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5500<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5501
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5502<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5503<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5504 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5505</pre>
5506
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5507<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5508<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5509 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5510
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5511<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5512<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5513 The second argument is a pointer to a <tt>va_list</tt> element to copy
5514 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5515
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5516<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5517<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5518 macro available in C. In a target-dependent way, it copies the
5519 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5520 element. This intrinsic is necessary because
5521 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5522 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5523
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5524</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5525
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5526<!-- ======================================================================= -->
5527<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5528 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5529</div>
5530
5531<div class="doc_text">
5532
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5533<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5534Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5535intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5536roots on the stack</a>, as well as garbage collector implementations that
5537require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5538barriers. Front-ends for type-safe garbage collected languages should generate
5539these intrinsics to make use of the LLVM garbage collectors. For more details,
5540see <a href="GarbageCollection.html">Accurate Garbage Collection with
5541LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5542
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5543<p>The garbage collection intrinsics only operate on objects in the generic
5544 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5545
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5546</div>
5547
5548<!-- _______________________________________________________________________ -->
5549<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5550 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5551</div>
5552
5553<div class="doc_text">
5554
5555<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5556<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5557 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5558</pre>
5559
5560<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5561<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5562 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5563
5564<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5565<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5566 root pointer. The second pointer (which must be either a constant or a
5567 global value address) contains the meta-data to be associated with the
5568 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5569
5570<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5571<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5572 location. At compile-time, the code generator generates information to allow
5573 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5574 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5575 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5576
5577</div>
5578
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5579<!-- _______________________________________________________________________ -->
5580<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5581 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5582</div>
5583
5584<div class="doc_text">
5585
5586<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5587<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5588 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5589</pre>
5590
5591<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5592<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5593 locations, allowing garbage collector implementations that require read
5594 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5595
5596<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5597<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5598 allocated from the garbage collector. The first object is a pointer to the
5599 start of the referenced object, if needed by the language runtime (otherwise
5600 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5601
5602<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5603<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5604 instruction, but may be replaced with substantially more complex code by the
5605 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5606 may only be used in a function which <a href="#gc">specifies a GC
5607 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5608
5609</div>
5610
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5611<!-- _______________________________________________________________________ -->
5612<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5613 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5614</div>
5615
5616<div class="doc_text">
5617
5618<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5619<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5620 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5621</pre>
5622
5623<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5624<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5625 locations, allowing garbage collector implementations that require write
5626 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5627
5628<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5629<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5630 object to store it to, and the third is the address of the field of Obj to
5631 store to. If the runtime does not require a pointer to the object, Obj may
5632 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5633
5634<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5635<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5636 instruction, but may be replaced with substantially more complex code by the
5637 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5638 may only be used in a function which <a href="#gc">specifies a GC
5639 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5640
5641</div>
5642
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5643<!-- ======================================================================= -->
5644<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5645 <a name="int_codegen">Code Generator Intrinsics</a>
5646</div>
5647
5648<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5649
5650<p>These intrinsics are provided by LLVM to expose special features that may
5651 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5652
5653</div>
5654
5655<!-- _______________________________________________________________________ -->
5656<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5657 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5658</div>
5659
5660<div class="doc_text">
5661
5662<h5>Syntax:</h5>
5663<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5664 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5665</pre>
5666
5667<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5668<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5669 target-specific value indicating the return address of the current function
5670 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5671
5672<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5673<p>The argument to this intrinsic indicates which function to return the address
5674 for. Zero indicates the calling function, one indicates its caller, etc.
5675 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5676
5677<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5678<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5679 indicating the return address of the specified call frame, or zero if it
5680 cannot be identified. The value returned by this intrinsic is likely to be
5681 incorrect or 0 for arguments other than zero, so it should only be used for
5682 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5683
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5684<p>Note that calling this intrinsic does not prevent function inlining or other
5685 aggressive transformations, so the value returned may not be that of the
5686 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5687
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5688</div>
5689
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5690<!-- _______________________________________________________________________ -->
5691<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5692 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5693</div>
5694
5695<div class="doc_text">
5696
5697<h5>Syntax:</h5>
5698<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5699 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5700</pre>
5701
5702<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5703<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5704 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5705
5706<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5707<p>The argument to this intrinsic indicates which function to return the frame
5708 pointer for. Zero indicates the calling function, one indicates its caller,
5709 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5710
5711<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5712<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5713 indicating the frame address of the specified call frame, or zero if it
5714 cannot be identified. The value returned by this intrinsic is likely to be
5715 incorrect or 0 for arguments other than zero, so it should only be used for
5716 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5717
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5718<p>Note that calling this intrinsic does not prevent function inlining or other
5719 aggressive transformations, so the value returned may not be that of the
5720 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5721
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5722</div>
5723
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5724<!-- _______________________________________________________________________ -->
5725<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5726 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5727</div>
5728
5729<div class="doc_text">
5730
5731<h5>Syntax:</h5>
5732<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5733 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5734</pre>
5735
5736<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5737<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5738 of the function stack, for use
5739 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5740 useful for implementing language features like scoped automatic variable
5741 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5742
5743<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5744<p>This intrinsic returns a opaque pointer value that can be passed
5745 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5746 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5747 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5748 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5749 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5750 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5751
5752</div>
5753
5754<!-- _______________________________________________________________________ -->
5755<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5756 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5757</div>
5758
5759<div class="doc_text">
5760
5761<h5>Syntax:</h5>
5762<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5763 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5764</pre>
5765
5766<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5767<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5768 the function stack to the state it was in when the
5769 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5770 executed. This is useful for implementing language features like scoped
5771 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5772
5773<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5774<p>See the description
5775 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5776
5777</div>
5778
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5779<!-- _______________________________________________________________________ -->
5780<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5781 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5782</div>
5783
5784<div class="doc_text">
5785
5786<h5>Syntax:</h5>
5787<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5788 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5789</pre>
5790
5791<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5792<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5793 insert a prefetch instruction if supported; otherwise, it is a noop.
5794 Prefetches have no effect on the behavior of the program but can change its
5795 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5796
5797<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5798<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5799 specifier determining if the fetch should be for a read (0) or write (1),
5800 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5801 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5802 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5803
5804<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5805<p>This intrinsic does not modify the behavior of the program. In particular,
5806 prefetches cannot trap and do not produce a value. On targets that support
5807 this intrinsic, the prefetch can provide hints to the processor cache for
5808 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5809
5810</div>
5811
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5812<!-- _______________________________________________________________________ -->
5813<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5814 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5815</div>
5816
5817<div class="doc_text">
5818
5819<h5>Syntax:</h5>
5820<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5821 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5822</pre>
5823
5824<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5825<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5826 Counter (PC) in a region of code to simulators and other tools. The method
5827 is target specific, but it is expected that the marker will use exported
5828 symbols to transmit the PC of the marker. The marker makes no guarantees
5829 that it will remain with any specific instruction after optimizations. It is
5830 possible that the presence of a marker will inhibit optimizations. The
5831 intended use is to be inserted after optimizations to allow correlations of
5832 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5833
5834<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5835<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5836
5837<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5838<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5839 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5840
5841</div>
5842
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5843<!-- _______________________________________________________________________ -->
5844<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5845 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5846</div>
5847
5848<div class="doc_text">
5849
5850<h5>Syntax:</h5>
5851<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5852 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5853</pre>
5854
5855<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5856<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5857 counter register (or similar low latency, high accuracy clocks) on those
5858 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5859 should map to RPCC. As the backing counters overflow quickly (on the order
5860 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5861
5862<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5863<p>When directly supported, reading the cycle counter should not modify any
5864 memory. Implementations are allowed to either return a application specific
5865 value or a system wide value. On backends without support, this is lowered
5866 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5867
5868</div>
5869
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5870<!-- ======================================================================= -->
5871<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5872 <a name="int_libc">Standard C Library Intrinsics</a>
5873</div>
5874
5875<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5876
5877<p>LLVM provides intrinsics for a few important standard C library functions.
5878 These intrinsics allow source-language front-ends to pass information about
5879 the alignment of the pointer arguments to the code generator, providing
5880 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5881
5882</div>
5883
5884<!-- _______________________________________________________________________ -->
5885<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5886 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5887</div>
5888
5889<div class="doc_text">
5890
5891<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5892<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]5893 integer bit width and for different address spaces. Not all targets support
5894 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5895
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5896<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5897 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5898 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5899 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5900 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5901 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5902 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5903 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5904 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5905</pre>
5906
5907<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5908<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5909 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5910
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5911<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5912 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5913
5914<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5915<p>The first argument is a pointer to the destination, the second is a pointer
5916 to the source. The third argument is an integer argument specifying the
5917 number of bytes to copy, and the fourth argument is the alignment of the
5918 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5919
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5920<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5921 then the caller guarantees that both the source and destination pointers are
5922 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5923
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5924<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5925<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5926 source location to the destination location, which are not allowed to
5927 overlap. It copies "len" bytes of memory over. If the argument is known to
5928 be aligned to some boundary, this can be specified as the fourth argument,
5929 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5930
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5931</div>
5932
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5933<!-- _______________________________________________________________________ -->
5934<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5935 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5936</div>
5937
5938<div class="doc_text">
5939
5940<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5941<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]5942 width and for different address space. Not all targets support all bit
5943 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5944
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5945<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5946 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5947 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5948 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5949 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5950 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5951 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5952 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5953 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5954</pre>
5955
5956<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5957<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5958 source location to the destination location. It is similar to the
5959 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5960 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5961
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5962<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5963 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5964
5965<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5966<p>The first argument is a pointer to the destination, the second is a pointer
5967 to the source. The third argument is an integer argument specifying the
5968 number of bytes to copy, and the fourth argument is the alignment of the
5969 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5970
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5971<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5972 then the caller guarantees that the source and destination pointers are
5973 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5974
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5975<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5976<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5977 source location to the destination location, which may overlap. It copies
5978 "len" bytes of memory over. If the argument is known to be aligned to some
5979 boundary, this can be specified as the fourth argument, otherwise it should
5980 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5981
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5982</div>
5983
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5984<!-- _______________________________________________________________________ -->
5985<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5986 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5987</div>
5988
5989<div class="doc_text">
5990
5991<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5992<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]5993 width and for different address spaces. Not all targets support all bit
5994 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5995
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5996<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5997 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5998 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5999 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
6000 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6001 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6002 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6003 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6004 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6005</pre>
6006
6007<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6008<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6009 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6010
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6011<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
6012 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6013
6014<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6015<p>The first argument is a pointer to the destination to fill, the second is the
6016 byte value to fill it with, the third argument is an integer argument
6017 specifying the number of bytes to fill, and the fourth argument is the known
6018 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6019
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6020<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6021 then the caller guarantees that the destination pointer is aligned to that
6022 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6023
6024<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6025<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6026 at the destination location. If the argument is known to be aligned to some
6027 boundary, this can be specified as the fourth argument, otherwise it should
6028 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6029
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6030</div>
6031
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6032<!-- _______________________________________________________________________ -->
6033<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6034 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6035</div>
6036
6037<div class="doc_text">
6038
6039<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6040<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6041 floating point or vector of floating point type. Not all targets support all
6042 types however.</p>
6043
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6044<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6045 declare float @llvm.sqrt.f32(float %Val)
6046 declare double @llvm.sqrt.f64(double %Val)
6047 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6048 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6049 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6050</pre>
6051
6052<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6053<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6054 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6055 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6056 behavior for negative numbers other than -0.0 (which allows for better
6057 optimization, because there is no need to worry about errno being
6058 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6059
6060<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6061<p>The argument and return value are floating point numbers of the same
6062 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6063
6064<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6065<p>This function returns the sqrt of the specified operand if it is a
6066 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6067
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6068</div>
6069
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6070<!-- _______________________________________________________________________ -->
6071<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6072 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6073</div>
6074
6075<div class="doc_text">
6076
6077<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6078<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6079 floating point or vector of floating point type. Not all targets support all
6080 types however.</p>
6081
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6082<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6083 declare float @llvm.powi.f32(float %Val, i32 %power)
6084 declare double @llvm.powi.f64(double %Val, i32 %power)
6085 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6086 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6087 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6088</pre>
6089
6090<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6091<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6092 specified (positive or negative) power. The order of evaluation of
6093 multiplications is not defined. When a vector of floating point type is
6094 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6095
6096<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6097<p>The second argument is an integer power, and the first is a value to raise to
6098 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6099
6100<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6101<p>This function returns the first value raised to the second power with an
6102 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6103
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6104</div>
6105
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6106<!-- _______________________________________________________________________ -->
6107<div class="doc_subsubsection">
6108 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
6109</div>
6110
6111<div class="doc_text">
6112
6113<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6114<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6115 floating point or vector of floating point type. Not all targets support all
6116 types however.</p>
6117
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6118<pre>
6119 declare float @llvm.sin.f32(float %Val)
6120 declare double @llvm.sin.f64(double %Val)
6121 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6122 declare fp128 @llvm.sin.f128(fp128 %Val)
6123 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6124</pre>
6125
6126<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6127<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6128
6129<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6130<p>The argument and return value are floating point numbers of the same
6131 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6132
6133<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6134<p>This function returns the sine of the specified operand, returning the same
6135 values as the libm <tt>sin</tt> functions would, and handles error conditions
6136 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6137
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6138</div>
6139
6140<!-- _______________________________________________________________________ -->
6141<div class="doc_subsubsection">
6142 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6143</div>
6144
6145<div class="doc_text">
6146
6147<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6148<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6149 floating point or vector of floating point type. Not all targets support all
6150 types however.</p>
6151
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6152<pre>
6153 declare float @llvm.cos.f32(float %Val)
6154 declare double @llvm.cos.f64(double %Val)
6155 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6156 declare fp128 @llvm.cos.f128(fp128 %Val)
6157 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6158</pre>
6159
6160<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6161<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6162
6163<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6164<p>The argument and return value are floating point numbers of the same
6165 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6166
6167<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6168<p>This function returns the cosine of the specified operand, returning the same
6169 values as the libm <tt>cos</tt> functions would, and handles error conditions
6170 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6171
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6172</div>
6173
6174<!-- _______________________________________________________________________ -->
6175<div class="doc_subsubsection">
6176 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6177</div>
6178
6179<div class="doc_text">
6180
6181<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6182<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6183 floating point or vector of floating point type. Not all targets support all
6184 types however.</p>
6185
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6186<pre>
6187 declare float @llvm.pow.f32(float %Val, float %Power)
6188 declare double @llvm.pow.f64(double %Val, double %Power)
6189 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6190 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6191 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6192</pre>
6193
6194<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6195<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6196 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6197
6198<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6199<p>The second argument is a floating point power, and the first is a value to
6200 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6201
6202<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6203<p>This function returns the first value raised to the second power, returning
6204 the same values as the libm <tt>pow</tt> functions would, and handles error
6205 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6206
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6207</div>
6208
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6209<!-- ======================================================================= -->
6210<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6211 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6212</div>
6213
6214<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6215
6216<p>LLVM provides intrinsics for a few important bit manipulation operations.
6217 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6218
6219</div>
6220
6221<!-- _______________________________________________________________________ -->
6222<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6223 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6224</div>
6225
6226<div class="doc_text">
6227
6228<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6229<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6230 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6231
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6232<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6233 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6234 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6235 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6236</pre>
6237
6238<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6239<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6240 values with an even number of bytes (positive multiple of 16 bits). These
6241 are useful for performing operations on data that is not in the target's
6242 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6243
6244<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6245<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6246 and low byte of the input i16 swapped. Similarly,
6247 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6248 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6249 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6250 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6251 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6252 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6253
6254</div>
6255
6256<!-- _______________________________________________________________________ -->
6257<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6258 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6259</div>
6260
6261<div class="doc_text">
6262
6263<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6264<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6265 width. Not all targets support all bit widths however.</p>
6266
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6267<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6268 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6269 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6270 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6271 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6272 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6273</pre>
6274
6275<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6276<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6277 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6278
6279<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6280<p>The only argument is the value to be counted. The argument may be of any
6281 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6282
6283<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6284<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6285
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6286</div>
6287
6288<!-- _______________________________________________________________________ -->
6289<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6290 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6291</div>
6292
6293<div class="doc_text">
6294
6295<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6296<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6297 integer bit width. Not all targets support all bit widths however.</p>
6298
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6299<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6300 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6301 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6302 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6303 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6304 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6305</pre>
6306
6307<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6308<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6309 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6310
6311<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6312<p>The only argument is the value to be counted. The argument may be of any
6313 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6314
6315<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6316<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6317 zeros in a variable. If the src == 0 then the result is the size in bits of
6318 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6319
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6320</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6321
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6322<!-- _______________________________________________________________________ -->
6323<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6324 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6325</div>
6326
6327<div class="doc_text">
6328
6329<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6330<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6331 integer bit width. Not all targets support all bit widths however.</p>
6332
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6333<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6334 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6335 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6336 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6337 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6338 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6339</pre>
6340
6341<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6342<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6343 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6344
6345<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6346<p>The only argument is the value to be counted. The argument may be of any
6347 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6348
6349<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6350<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6351 zeros in a variable. If the src == 0 then the result is the size in bits of
6352 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6353
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6354</div>
6355
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6356<!-- ======================================================================= -->
6357<div class="doc_subsection">
6358 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6359</div>
6360
6361<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6362
6363<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6364
6365</div>
6366
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6367<!-- _______________________________________________________________________ -->
6368<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6369 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6370</div>
6371
6372<div class="doc_text">
6373
6374<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6375<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6376 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6377
6378<pre>
6379 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6380 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6381 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6382</pre>
6383
6384<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6385<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6386 a signed addition of the two arguments, and indicate whether an overflow
6387 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6388
6389<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6390<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6391 be of integer types of any bit width, but they must have the same bit
6392 width. The second element of the result structure must be of
6393 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6394 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6395
6396<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6397<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6398 a signed addition of the two variables. They return a structure &mdash; the
6399 first element of which is the signed summation, and the second element of
6400 which is a bit specifying if the signed summation resulted in an
6401 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6402
6403<h5>Examples:</h5>
6404<pre>
6405 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6406 %sum = extractvalue {i32, i1} %res, 0
6407 %obit = extractvalue {i32, i1} %res, 1
6408 br i1 %obit, label %overflow, label %normal
6409</pre>
6410
6411</div>
6412
6413<!-- _______________________________________________________________________ -->
6414<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6415 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6416</div>
6417
6418<div class="doc_text">
6419
6420<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6421<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6422 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6423
6424<pre>
6425 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6426 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6427 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6428</pre>
6429
6430<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6431<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6432 an unsigned addition of the two arguments, and indicate whether a carry
6433 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6434
6435<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6436<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6437 be of integer types of any bit width, but they must have the same bit
6438 width. The second element of the result structure must be of
6439 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6440 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6441
6442<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6443<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6444 an unsigned addition of the two arguments. They return a structure &mdash;
6445 the first element of which is the sum, and the second element of which is a
6446 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6447
6448<h5>Examples:</h5>
6449<pre>
6450 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6451 %sum = extractvalue {i32, i1} %res, 0
6452 %obit = extractvalue {i32, i1} %res, 1
6453 br i1 %obit, label %carry, label %normal
6454</pre>
6455
6456</div>
6457
6458<!-- _______________________________________________________________________ -->
6459<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6460 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6461</div>
6462
6463<div class="doc_text">
6464
6465<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6466<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6467 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6468
6469<pre>
6470 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6471 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6472 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6473</pre>
6474
6475<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6476<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6477 a signed subtraction of the two arguments, and indicate whether an overflow
6478 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6479
6480<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6481<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6482 be of integer types of any bit width, but they must have the same bit
6483 width. The second element of the result structure must be of
6484 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6485 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6486
6487<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6488<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6489 a signed subtraction of the two arguments. They return a structure &mdash;
6490 the first element of which is the subtraction, and the second element of
6491 which is a bit specifying if the signed subtraction resulted in an
6492 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6493
6494<h5>Examples:</h5>
6495<pre>
6496 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6497 %sum = extractvalue {i32, i1} %res, 0
6498 %obit = extractvalue {i32, i1} %res, 1
6499 br i1 %obit, label %overflow, label %normal
6500</pre>
6501
6502</div>
6503
6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6506 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6507</div>
6508
6509<div class="doc_text">
6510
6511<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6512<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6513 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6514
6515<pre>
6516 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6517 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6518 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6519</pre>
6520
6521<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6522<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6523 an unsigned subtraction of the two arguments, and indicate whether an
6524 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6525
6526<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6527<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6528 be of integer types of any bit width, but they must have the same bit
6529 width. The second element of the result structure must be of
6530 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6531 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6532
6533<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6534<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6535 an unsigned subtraction of the two arguments. They return a structure &mdash;
6536 the first element of which is the subtraction, and the second element of
6537 which is a bit specifying if the unsigned subtraction resulted in an
6538 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6539
6540<h5>Examples:</h5>
6541<pre>
6542 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6543 %sum = extractvalue {i32, i1} %res, 0
6544 %obit = extractvalue {i32, i1} %res, 1
6545 br i1 %obit, label %overflow, label %normal
6546</pre>
6547
6548</div>
6549
6550<!-- _______________________________________________________________________ -->
6551<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6552 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6553</div>
6554
6555<div class="doc_text">
6556
6557<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6558<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6559 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6560
6561<pre>
6562 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6563 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6564 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6565</pre>
6566
6567<h5>Overview:</h5>
6568
6569<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6570 a signed multiplication of the two arguments, and indicate whether an
6571 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6572
6573<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6574<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6575 be of integer types of any bit width, but they must have the same bit
6576 width. The second element of the result structure must be of
6577 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6578 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6579
6580<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6581<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6582 a signed multiplication of the two arguments. They return a structure &mdash;
6583 the first element of which is the multiplication, and the second element of
6584 which is a bit specifying if the signed multiplication resulted in an
6585 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6586
6587<h5>Examples:</h5>
6588<pre>
6589 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6590 %sum = extractvalue {i32, i1} %res, 0
6591 %obit = extractvalue {i32, i1} %res, 1
6592 br i1 %obit, label %overflow, label %normal
6593</pre>
6594
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6595</div>
6596
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6597<!-- _______________________________________________________________________ -->
6598<div class="doc_subsubsection">
6599 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6600</div>
6601
6602<div class="doc_text">
6603
6604<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6605<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6606 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6607
6608<pre>
6609 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6610 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6611 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6612</pre>
6613
6614<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6615<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6616 a unsigned multiplication of the two arguments, and indicate whether an
6617 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6618
6619<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6620<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6621 be of integer types of any bit width, but they must have the same bit
6622 width. The second element of the result structure must be of
6623 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6624 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6625
6626<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6627<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6628 an unsigned multiplication of the two arguments. They return a structure
6629 &mdash; the first element of which is the multiplication, and the second
6630 element of which is a bit specifying if the unsigned multiplication resulted
6631 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6632
6633<h5>Examples:</h5>
6634<pre>
6635 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6636 %sum = extractvalue {i32, i1} %res, 0
6637 %obit = extractvalue {i32, i1} %res, 1
6638 br i1 %obit, label %overflow, label %normal
6639</pre>
6640
6641</div>
6642
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6643<!-- ======================================================================= -->
6644<div class="doc_subsection">
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6645 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
6646</div>
6647
6648<div class="doc_text">
6649
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6650<p>Half precision floating point is a storage-only format. This means that it is
6651 a dense encoding (in memory) but does not support computation in the
6652 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6653
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6654<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6655 value as an i16, then convert it to float with <a
6656 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
6657 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6658 double etc). To store the value back to memory, it is first converted to
6659 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6660 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
6661 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6662</div>
6663
6664<!-- _______________________________________________________________________ -->
6665<div class="doc_subsubsection">
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6666 <a name="int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6667</div>
6668
6669<div class="doc_text">
6670
6671<h5>Syntax:</h5>
6672<pre>
6673 declare i16 @llvm.convert.to.fp16(f32 %a)
6674</pre>
6675
6676<h5>Overview:</h5>
6677<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6678 a conversion from single precision floating point format to half precision
6679 floating point format.</p>
6680
6681<h5>Arguments:</h5>
6682<p>The intrinsic function contains single argument - the value to be
6683 converted.</p>
6684
6685<h5>Semantics:</h5>
6686<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6687 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6688 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6689 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6690
6691<h5>Examples:</h5>
6692<pre>
6693 %res = call i16 @llvm.convert.to.fp16(f32 %a)
6694 store i16 %res, i16* @x, align 2
6695</pre>
6696
6697</div>
6698
6699<!-- _______________________________________________________________________ -->
6700<div class="doc_subsubsection">
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6701 <a name="int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6702</div>
6703
6704<div class="doc_text">
6705
6706<h5>Syntax:</h5>
6707<pre>
6708 declare f32 @llvm.convert.from.fp16(i16 %a)
6709</pre>
6710
6711<h5>Overview:</h5>
6712<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
6713 a conversion from half precision floating point format to single precision
6714 floating point format.</p>
6715
6716<h5>Arguments:</h5>
6717<p>The intrinsic function contains single argument - the value to be
6718 converted.</p>
6719
6720<h5>Semantics:</h5>
6721<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6722 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6723 precision floating point format. The input half-float value is represented by
6724 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6725
6726<h5>Examples:</h5>
6727<pre>
6728 %a = load i16* @x, align 2
6729 %res = call f32 @llvm.convert.from.fp16(i16 %a)
6730</pre>
6731
6732</div>
6733
6734<!-- ======================================================================= -->
6735<div class="doc_subsection">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6736 <a name="int_debugger">Debugger Intrinsics</a>
6737</div>
6738
6739<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6740
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6741<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6742 prefix), are described in
6743 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6744 Level Debugging</a> document.</p>
6745
6746</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6747
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6748<!-- ======================================================================= -->
6749<div class="doc_subsection">
6750 <a name="int_eh">Exception Handling Intrinsics</a>
6751</div>
6752
6753<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6754
6755<p>The LLVM exception handling intrinsics (which all start with
6756 <tt>llvm.eh.</tt> prefix), are described in
6757 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6758 Handling</a> document.</p>
6759
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6760</div>
6761
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6762<!-- ======================================================================= -->
6763<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6764 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6765</div>
6766
6767<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6768
6769<p>This intrinsic makes it possible to excise one parameter, marked with
6770 the <tt>nest</tt> attribute, from a function. The result is a callable
6771 function pointer lacking the nest parameter - the caller does not need to
6772 provide a value for it. Instead, the value to use is stored in advance in a
6773 "trampoline", a block of memory usually allocated on the stack, which also
6774 contains code to splice the nest value into the argument list. This is used
6775 to implement the GCC nested function address extension.</p>
6776
6777<p>For example, if the function is
6778 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6779 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6780 follows:</p>
6781
6782<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6783<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6784 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6785 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6786 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6787 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6788</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6789</div>
6790
6791<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6792 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6793
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6794</div>
6795
6796<!-- _______________________________________________________________________ -->
6797<div class="doc_subsubsection">
6798 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6799</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6800
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6801<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6802
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6803<h5>Syntax:</h5>
6804<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6805 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6806</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6807
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6808<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6809<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6810 function pointer suitable for executing it.</p>
6811
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6812<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6813<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6814 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6815 sufficiently aligned block of memory; this memory is written to by the
6816 intrinsic. Note that the size and the alignment are target-specific - LLVM
6817 currently provides no portable way of determining them, so a front-end that
6818 generates this intrinsic needs to have some target-specific knowledge.
6819 The <tt>func</tt> argument must hold a function bitcast to
6820 an <tt>i8*</tt>.</p>
6821
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6822<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6823<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6824 dependent code, turning it into a function. A pointer to this function is
6825 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6826 function pointer type</a> before being called. The new function's signature
6827 is the same as that of <tt>func</tt> with any arguments marked with
6828 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6829 is allowed, and it must be of pointer type. Calling the new function is
6830 equivalent to calling <tt>func</tt> with the same argument list, but
6831 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6832 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6833 by <tt>tramp</tt> is modified, then the effect of any later call to the
6834 returned function pointer is undefined.</p>
6835
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6836</div>
6837
6838<!-- ======================================================================= -->
6839<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6840 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6841</div>
6842
6843<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6845<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6846 hardware constructs for atomic operations and memory synchronization. This
6847 provides an interface to the hardware, not an interface to the programmer. It
6848 is aimed at a low enough level to allow any programming models or APIs
6849 (Application Programming Interfaces) which need atomic behaviors to map
6850 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6851 hardware provides a "universal IR" for source languages, it also provides a
6852 starting point for developing a "universal" atomic operation and
6853 synchronization IR.</p>
6854
6855<p>These do <em>not</em> form an API such as high-level threading libraries,
6856 software transaction memory systems, atomic primitives, and intrinsic
6857 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6858 application libraries. The hardware interface provided by LLVM should allow
6859 a clean implementation of all of these APIs and parallel programming models.
6860 No one model or paradigm should be selected above others unless the hardware
6861 itself ubiquitously does so.</p>
6862
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6863</div>
6864
6865<!-- _______________________________________________________________________ -->
6866<div class="doc_subsubsection">
6867 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6868</div>
6869<div class="doc_text">
6870<h5>Syntax:</h5>
6871<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6872 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6873</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6874
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6875<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6876<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6877 specific pairs of memory access types.</p>
6878
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6879<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6880<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6881 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6882 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6883 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6884
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6885<ul>
6886 <li><tt>ll</tt>: load-load barrier</li>
6887 <li><tt>ls</tt>: load-store barrier</li>
6888 <li><tt>sl</tt>: store-load barrier</li>
6889 <li><tt>ss</tt>: store-store barrier</li>
6890 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6891</ul>
6892
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6893<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6894<p>This intrinsic causes the system to enforce some ordering constraints upon
6895 the loads and stores of the program. This barrier does not
6896 indicate <em>when</em> any events will occur, it only enforces
6897 an <em>order</em> in which they occur. For any of the specified pairs of load
6898 and store operations (f.ex. load-load, or store-load), all of the first
6899 operations preceding the barrier will complete before any of the second
6900 operations succeeding the barrier begin. Specifically the semantics for each
6901 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6902
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6903<ul>
6904 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6905 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6906 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6907 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6908 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6909 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6910 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6911 load after the barrier begins.</li>
6912</ul>
6913
6914<p>These semantics are applied with a logical "and" behavior when more than one
6915 is enabled in a single memory barrier intrinsic.</p>
6916
6917<p>Backends may implement stronger barriers than those requested when they do
6918 not support as fine grained a barrier as requested. Some architectures do
6919 not need all types of barriers and on such architectures, these become
6920 noops.</p>
6921
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6922<h5>Example:</h5>
6923<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6924%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6925%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6926 store i32 4, %ptr
6927
6928%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6929 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6930 <i>; guarantee the above finishes</i>
6931 store i32 8, %ptr <i>; before this begins</i>
6932</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6933
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6934</div>
6935
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6936<!-- _______________________________________________________________________ -->
6937<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6938 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6939</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6940
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6941<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6942
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6943<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6944<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6945 any integer bit width and for different address spaces. Not all targets
6946 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6947
6948<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6949 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6950 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6951 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6952 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6953</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6954
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6955<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6956<p>This loads a value in memory and compares it to a given value. If they are
6957 equal, it stores a new value into the memory.</p>
6958
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6959<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6960<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6961 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6962 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6963 this integer type. While any bit width integer may be used, targets may only
6964 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6965
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6966<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6967<p>This entire intrinsic must be executed atomically. It first loads the value
6968 in memory pointed to by <tt>ptr</tt> and compares it with the
6969 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6970 memory. The loaded value is yielded in all cases. This provides the
6971 equivalent of an atomic compare-and-swap operation within the SSA
6972 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6973
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6974<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6975<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6976%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6977%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6978 store i32 4, %ptr
6979
6980%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6981%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6982 <i>; yields {i32}:result1 = 4</i>
6983%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6984%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6985
6986%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6987%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6988 <i>; yields {i32}:result2 = 8</i>
6989%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6990
6991%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6992</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6993
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6994</div>
6995
6996<!-- _______________________________________________________________________ -->
6997<div class="doc_subsubsection">
6998 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6999</div>
7000<div class="doc_text">
7001<h5>Syntax:</h5>
7002
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7003<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7004 integer bit width. Not all targets support all bit widths however.</p>
7005
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7006<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7007 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
7008 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
7009 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
7010 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7011</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7012
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7013<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7014<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7015 the value from memory. It then stores the value in <tt>val</tt> in the memory
7016 at <tt>ptr</tt>.</p>
7017
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7018<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7019<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7020 the <tt>val</tt> argument and the result must be integers of the same bit
7021 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7022 integer type. The targets may only lower integer representations they
7023 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7024
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7025<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7026<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7027 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7028 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7029
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7030<h5>Examples:</h5>
7031<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7032%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7033%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7034 store i32 4, %ptr
7035
7036%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7037%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7038 <i>; yields {i32}:result1 = 4</i>
7039%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7040%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7041
7042%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7043%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7044 <i>; yields {i32}:result2 = 8</i>
7045
7046%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7047%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7048</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7049
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7050</div>
7051
7052<!-- _______________________________________________________________________ -->
7053<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7054 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7055
7056</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7057
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7058<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7059
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7060<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7061<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7062 any integer bit width. Not all targets support all bit widths however.</p>
7063
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7064<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7065 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7066 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7067 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7068 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7069</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7070
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7071<h5>Overview:</h5>
7072<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7073 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7074
7075<h5>Arguments:</h5>
7076<p>The intrinsic takes two arguments, the first a pointer to an integer value
7077 and the second an integer value. The result is also an integer value. These
7078 integer types can have any bit width, but they must all have the same bit
7079 width. The targets may only lower integer representations they support.</p>
7080
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7081<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7082<p>This intrinsic does a series of operations atomically. It first loads the
7083 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7084 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7085
7086<h5>Examples:</h5>
7087<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7088%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7089%ptr = bitcast i8* %mallocP to i32*
7090 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7091%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7092 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7093%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7094 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7095%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7096 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7097%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7098</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7099
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7100</div>
7101
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7102<!-- _______________________________________________________________________ -->
7103<div class="doc_subsubsection">
7104 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
7105
7106</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7107
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7108<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7109
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7110<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7111<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7112 any integer bit width and for different address spaces. Not all targets
7113 support all bit widths however.</p>
7114
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7115<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7116 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7117 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7118 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7119 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7120</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7121
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7122<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7123<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7124 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7125
7126<h5>Arguments:</h5>
7127<p>The intrinsic takes two arguments, the first a pointer to an integer value
7128 and the second an integer value. The result is also an integer value. These
7129 integer types can have any bit width, but they must all have the same bit
7130 width. The targets may only lower integer representations they support.</p>
7131
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7132<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7133<p>This intrinsic does a series of operations atomically. It first loads the
7134 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7135 result to <tt>ptr</tt>. It yields the original value stored
7136 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7137
7138<h5>Examples:</h5>
7139<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7140%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7141%ptr = bitcast i8* %mallocP to i32*
7142 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7143%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7144 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7145%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7146 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7147%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7148 <i>; yields {i32}:result3 = 2</i>
7149%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7150</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7151
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7152</div>
7153
7154<!-- _______________________________________________________________________ -->
7155<div class="doc_subsubsection">
7156 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
7157 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
7158 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
7159 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7160</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7161
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7162<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7163
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7164<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7165<p>These are overloaded intrinsics. You can
7166 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7167 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7168 bit width and for different address spaces. Not all targets support all bit
7169 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7170
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7171<pre>
7172 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7173 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7174 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7175 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7176</pre>
7177
7178<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7179 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7180 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7181 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7182 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7183</pre>
7184
7185<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7186 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7187 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7188 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7189 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7190</pre>
7191
7192<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7193 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7194 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7195 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7196 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7197</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7198
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7199<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7200<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7201 the value stored in memory at <tt>ptr</tt>. It yields the original value
7202 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7203
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7204<h5>Arguments:</h5>
7205<p>These intrinsics take two arguments, the first a pointer to an integer value
7206 and the second an integer value. The result is also an integer value. These
7207 integer types can have any bit width, but they must all have the same bit
7208 width. The targets may only lower integer representations they support.</p>
7209
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7210<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7211<p>These intrinsics does a series of operations atomically. They first load the
7212 value stored at <tt>ptr</tt>. They then do the bitwise
7213 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7214 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7215
7216<h5>Examples:</h5>
7217<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7218%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7219%ptr = bitcast i8* %mallocP to i32*
7220 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7221%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7222 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7223%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7224 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7225%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7226 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7227%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7228 <i>; yields {i32}:result3 = FF</i>
7229%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7230</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7231
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7232</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7233
7234<!-- _______________________________________________________________________ -->
7235<div class="doc_subsubsection">
7236 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7237 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7238 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7239 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7240</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7241
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7242<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7243
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7244<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7245<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7246 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7247 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7248 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7249
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250<pre>
7251 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7252 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7253 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7254 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7255</pre>
7256
7257<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7258 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7259 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7260 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7261 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7262</pre>
7263
7264<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7265 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7266 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7267 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7268 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7269</pre>
7270
7271<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7272 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7273 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7274 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7275 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7276</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7277
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7278<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7279<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7280 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7281 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7282
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7283<h5>Arguments:</h5>
7284<p>These intrinsics take two arguments, the first a pointer to an integer value
7285 and the second an integer value. The result is also an integer value. These
7286 integer types can have any bit width, but they must all have the same bit
7287 width. The targets may only lower integer representations they support.</p>
7288
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7289<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7290<p>These intrinsics does a series of operations atomically. They first load the
7291 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7292 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7293 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7294
7295<h5>Examples:</h5>
7296<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7297%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7298%ptr = bitcast i8* %mallocP to i32*
7299 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7300%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7301 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7302%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7303 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7304%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7305 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7306%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7307 <i>; yields {i32}:result3 = 8</i>
7308%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7309</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7310
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7311</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7312
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7313
7314<!-- ======================================================================= -->
7315<div class="doc_subsection">
7316 <a name="int_memorymarkers">Memory Use Markers</a>
7317</div>
7318
7319<div class="doc_text">
7320
7321<p>This class of intrinsics exists to information about the lifetime of memory
7322 objects and ranges where variables are immutable.</p>
7323
7324</div>
7325
7326<!-- _______________________________________________________________________ -->
7327<div class="doc_subsubsection">
7328 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7329</div>
7330
7331<div class="doc_text">
7332
7333<h5>Syntax:</h5>
7334<pre>
7335 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7336</pre>
7337
7338<h5>Overview:</h5>
7339<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7340 object's lifetime.</p>
7341
7342<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7343<p>The first argument is a constant integer representing the size of the
7344 object, or -1 if it is variable sized. The second argument is a pointer to
7345 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7346
7347<h5>Semantics:</h5>
7348<p>This intrinsic indicates that before this point in the code, the value of the
7349 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewycky8d336592009-10-27 16:56:58 +0000[diff] [blame]7350 never be used and has an undefined value. A load from the pointer that
7351 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7352 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7353
7354</div>
7355
7356<!-- _______________________________________________________________________ -->
7357<div class="doc_subsubsection">
7358 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7359</div>
7360
7361<div class="doc_text">
7362
7363<h5>Syntax:</h5>
7364<pre>
7365 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7366</pre>
7367
7368<h5>Overview:</h5>
7369<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7370 object's lifetime.</p>
7371
7372<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7373<p>The first argument is a constant integer representing the size of the
7374 object, or -1 if it is variable sized. The second argument is a pointer to
7375 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7376
7377<h5>Semantics:</h5>
7378<p>This intrinsic indicates that after this point in the code, the value of the
7379 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7380 never be used and has an undefined value. Any stores into the memory object
7381 following this intrinsic may be removed as dead.
7382
7383</div>
7384
7385<!-- _______________________________________________________________________ -->
7386<div class="doc_subsubsection">
7387 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7388</div>
7389
7390<div class="doc_text">
7391
7392<h5>Syntax:</h5>
7393<pre>
7394 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7395</pre>
7396
7397<h5>Overview:</h5>
7398<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7399 a memory object will not change.</p>
7400
7401<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7402<p>The first argument is a constant integer representing the size of the
7403 object, or -1 if it is variable sized. The second argument is a pointer to
7404 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7405
7406<h5>Semantics:</h5>
7407<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7408 the return value, the referenced memory location is constant and
7409 unchanging.</p>
7410
7411</div>
7412
7413<!-- _______________________________________________________________________ -->
7414<div class="doc_subsubsection">
7415 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7416</div>
7417
7418<div class="doc_text">
7419
7420<h5>Syntax:</h5>
7421<pre>
7422 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7423</pre>
7424
7425<h5>Overview:</h5>
7426<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7427 a memory object are mutable.</p>
7428
7429<h5>Arguments:</h5>
7430<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7431 The second argument is a constant integer representing the size of the
7432 object, or -1 if it is variable sized and the third argument is a pointer
7433 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7434
7435<h5>Semantics:</h5>
7436<p>This intrinsic indicates that the memory is mutable again.</p>
7437
7438</div>
7439
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7440<!-- ======================================================================= -->
7441<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7442 <a name="int_general">General Intrinsics</a>
7443</div>
7444
7445<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7446
7447<p>This class of intrinsics is designed to be generic and has no specific
7448 purpose.</p>
7449
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7450</div>
7451
7452<!-- _______________________________________________________________________ -->
7453<div class="doc_subsubsection">
7454 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7455</div>
7456
7457<div class="doc_text">
7458
7459<h5>Syntax:</h5>
7460<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]7461 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7462</pre>
7463
7464<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7465<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7466
7467<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7468<p>The first argument is a pointer to a value, the second is a pointer to a
7469 global string, the third is a pointer to a global string which is the source
7470 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7471
7472<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7473<p>This intrinsic allows annotation of local variables with arbitrary strings.
7474 This can be useful for special purpose optimizations that want to look for
7475 these annotations. These have no other defined use, they are ignored by code
7476 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7477
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7478</div>
7479
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7480<!-- _______________________________________________________________________ -->
7481<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7482 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7483</div>
7484
7485<div class="doc_text">
7486
7487<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7488<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7489 any integer bit width.</p>
7490
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7491<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]7492 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7493 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7494 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7495 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7496 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7497</pre>
7498
7499<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7500<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7501
7502<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7503<p>The first argument is an integer value (result of some expression), the
7504 second is a pointer to a global string, the third is a pointer to a global
7505 string which is the source file name, and the last argument is the line
7506 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7507
7508<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7509<p>This intrinsic allows annotations to be put on arbitrary expressions with
7510 arbitrary strings. This can be useful for special purpose optimizations that
7511 want to look for these annotations. These have no other defined use, they
7512 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7513
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7514</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7515
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7516<!-- _______________________________________________________________________ -->
7517<div class="doc_subsubsection">
7518 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7519</div>
7520
7521<div class="doc_text">
7522
7523<h5>Syntax:</h5>
7524<pre>
7525 declare void @llvm.trap()
7526</pre>
7527
7528<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7529<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7530
7531<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7532<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7533
7534<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7535<p>This intrinsics is lowered to the target dependent trap instruction. If the
7536 target does not have a trap instruction, this intrinsic will be lowered to
7537 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7538
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7539</div>
7540
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7541<!-- _______________________________________________________________________ -->
7542<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7543 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7544</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7545
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7546<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7547
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7548<h5>Syntax:</h5>
7549<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7550 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7551</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7552
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7553<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7554<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7555 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7556 ensure that it is placed on the stack before local variables.</p>
7557
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7558<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7559<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7560 arguments. The first argument is the value loaded from the stack
7561 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7562 that has enough space to hold the value of the guard.</p>
7563
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7564<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7565<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7566 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7567 stack. This is to ensure that if a local variable on the stack is
7568 overwritten, it will destroy the value of the guard. When the function exits,
7569 the guard on the stack is checked against the original guard. If they're
7570 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7571 function.</p>
7572
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7573</div>
7574
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7575<!-- _______________________________________________________________________ -->
7576<div class="doc_subsubsection">
7577 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7578</div>
7579
7580<div class="doc_text">
7581
7582<h5>Syntax:</h5>
7583<pre>
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7584 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7585 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7586</pre>
7587
7588<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7589<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopherd003c5b2010-01-08 21:42:39 +0000[diff] [blame]7590 to the optimizers to discover at compile time either a) when an
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7591 operation like memcpy will either overflow a buffer that corresponds to
7592 an object, or b) to determine that a runtime check for overflow isn't
7593 necessary. An object in this context means an allocation of a
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7594 specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7595
7596<h5>Arguments:</h5>
7597<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7598 argument is a pointer to or into the <tt>object</tt>. The second argument
7599 is a boolean 0 or 1. This argument determines whether you want the
7600 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7601 1, variables are not allowed.</p>
7602
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7603<h5>Semantics:</h5>
7604<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7605 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7606 (depending on the <tt>type</tt> argument if the size cannot be determined
7607 at compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7608
7609</div>
7610
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7611<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7612<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7613<address>
7614 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7618
7619 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7620 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7621 Last modified: $Date$
7622</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7623
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7624</body>
7625</html>