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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / b55a1ee36c4c719b55730a0099e3c2d5c42e0f05 / . / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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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>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]258 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]259 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]260 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]261 <ol>
262 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]263 </ol>
264 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]265 <li><a href="#int_atomics">Atomic intrinsics</a>
266 <ol>
267 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
268 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
269 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
270 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
271 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
272 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
273 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
274 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
275 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
276 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
277 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
278 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
279 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
280 </ol>
281 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]282 <li><a href="#int_memorymarkers">Memory Use Markers</a>
283 <ol>
284 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
285 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
286 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
287 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
288 </ol>
289 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]290 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]291 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]292 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]293 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]294 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]295 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]296 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]297 '<tt>llvm.trap</tt>' Intrinsic</a></li>
298 <li><a href="#int_stackprotector">
299 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]300 <li><a href="#int_objectsize">
301 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]302 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]303 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]304 </ol>
305 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]306</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]307
308<div class="doc_author">
309 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
310 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]311</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]312
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]313<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]314<div class="doc_section"> <a name="abstract">Abstract </a></div>
315<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]316
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]317<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]318
319<p>This document is a reference manual for the LLVM assembly language. LLVM is
320 a Static Single Assignment (SSA) based representation that provides type
321 safety, low-level operations, flexibility, and the capability of representing
322 'all' high-level languages cleanly. It is the common code representation
323 used throughout all phases of the LLVM compilation strategy.</p>
324
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]325</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]328<div class="doc_section"> <a name="introduction">Introduction</a> </div>
329<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]331<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]332
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]333<p>The LLVM code representation is designed to be used in three different forms:
334 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
335 for fast loading by a Just-In-Time compiler), and as a human readable
336 assembly language representation. This allows LLVM to provide a powerful
337 intermediate representation for efficient compiler transformations and
338 analysis, while providing a natural means to debug and visualize the
339 transformations. The three different forms of LLVM are all equivalent. This
340 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]341
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]342<p>The LLVM representation aims to be light-weight and low-level while being
343 expressive, typed, and extensible at the same time. It aims to be a
344 "universal IR" of sorts, by being at a low enough level that high-level ideas
345 may be cleanly mapped to it (similar to how microprocessors are "universal
346 IR's", allowing many source languages to be mapped to them). By providing
347 type information, LLVM can be used as the target of optimizations: for
348 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]349 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]350 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]352</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]354<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]355<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]356
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]357<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]359<p>It is important to note that this document describes 'well formed' LLVM
360 assembly language. There is a difference between what the parser accepts and
361 what is considered 'well formed'. For example, the following instruction is
362 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]363
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]364<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]365<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]366%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]367</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]368</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]370<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
371 LLVM infrastructure provides a verification pass that may be used to verify
372 that an LLVM module is well formed. This pass is automatically run by the
373 parser after parsing input assembly and by the optimizer before it outputs
374 bitcode. The violations pointed out by the verifier pass indicate bugs in
375 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]376
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]378
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]379<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]381<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]382<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]383<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]384
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]385<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]386
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]387<p>LLVM identifiers come in two basic types: global and local. Global
388 identifiers (functions, global variables) begin with the <tt>'@'</tt>
389 character. Local identifiers (register names, types) begin with
390 the <tt>'%'</tt> character. Additionally, there are three different formats
391 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]393<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]394 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]395 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
396 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
397 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
398 other characters in their names can be surrounded with quotes. Special
399 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
400 ASCII code for the character in hexadecimal. In this way, any character
401 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]402
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]403 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]404 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]405
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]406 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]407 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]408</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]410<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 don't need to worry about name clashes with reserved words, and the set of
412 reserved words may be expanded in the future without penalty. Additionally,
413 unnamed identifiers allow a compiler to quickly come up with a temporary
414 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]415
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]416<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]417 languages. There are keywords for different opcodes
418 ('<tt><a href="#i_add">add</a></tt>',
419 '<tt><a href="#i_bitcast">bitcast</a></tt>',
420 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
421 ('<tt><a href="#t_void">void</a></tt>',
422 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
423 reserved words cannot conflict with variable names, because none of them
424 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]425
426<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]427 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]429<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]433%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]434</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]435</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]437<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]439<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]441%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]443</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]445<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]447<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448<pre>
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]449%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
450%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]451%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]453</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]455<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
456 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]458<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]460 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]461
462 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]463 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]464
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]465 <li>Unnamed temporaries are numbered sequentially</li>
466</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]468<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469 demonstrating instructions, we will follow an instruction with a comment that
470 defines the type and name of value produced. Comments are shown in italic
471 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]473</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]474
475<!-- *********************************************************************** -->
476<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
477<!-- *********************************************************************** -->
478
479<!-- ======================================================================= -->
480<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
481</div>
482
483<div class="doc_text">
484
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]485<p>LLVM programs are composed of "Module"s, each of which is a translation unit
486 of the input programs. Each module consists of functions, global variables,
487 and symbol table entries. Modules may be combined together with the LLVM
488 linker, which merges function (and global variable) definitions, resolves
489 forward declarations, and merges symbol table entries. Here is an example of
490 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]492<div class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]493<pre>
494<i>; Declare the string constant as a global constant.</i>
495<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]496
497<i>; External declaration of the puts function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]498<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]499
500<i>; Definition of main function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]501define i32 @main() { <i>; i32()* </i>
502 <i>; Convert [13 x i8]* to i8 *...</i>
503 %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]504
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]505 <i>; Call puts function to write out the string to stdout.</i>
506 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]507 <a href="#i_ret">ret</a> i32 0<br>}
508
509<i>; Named metadata</i>
510!1 = metadata !{i32 41}
511!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]512</pre>
513</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]514
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]515<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]516 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]517 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]518 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
519 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]521<p>In general, a module is made up of a list of global values, where both
522 functions and global variables are global values. Global values are
523 represented by a pointer to a memory location (in this case, a pointer to an
524 array of char, and a pointer to a function), and have one of the
525 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]527</div>
528
529<!-- ======================================================================= -->
530<div class="doc_subsection">
531 <a name="linkage">Linkage Types</a>
532</div>
533
534<div class="doc_text">
535
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]536<p>All Global Variables and Functions have one of the following types of
537 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]538
539<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]540 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]541 <dd>Global values with private linkage are only directly accessible by objects
542 in the current module. In particular, linking code into a module with an
543 private global value may cause the private to be renamed as necessary to
544 avoid collisions. Because the symbol is private to the module, all
545 references can be updated. This doesn't show up in any symbol table in the
546 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]547
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]549 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere1eaf912009-08-24 04:32:16 +0000[diff] [blame]550 removed by the linker after evaluation. Note that (unlike private
551 symbols) linker_private symbols are subject to coalescing by the linker:
552 weak symbols get merged and redefinitions are rejected. However, unlike
553 normal strong symbols, they are removed by the linker from the final
554 linked image (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]555
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]557 <dd>Similar to private, but the value shows as a local symbol
558 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
559 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]560
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]561 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]562 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]563 into the object file corresponding to the LLVM module. They exist to
564 allow inlining and other optimizations to take place given knowledge of
565 the definition of the global, which is known to be somewhere outside the
566 module. Globals with <tt>available_externally</tt> linkage are allowed to
567 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
568 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]569
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]571 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]572 the same name when linkage occurs. This can be used to implement
573 some forms of inline functions, templates, or other code which must be
574 generated in each translation unit that uses it, but where the body may
575 be overridden with a more definitive definition later. Unreferenced
576 <tt>linkonce</tt> globals are allowed to be discarded. Note that
577 <tt>linkonce</tt> linkage does not actually allow the optimizer to
578 inline the body of this function into callers because it doesn't know if
579 this definition of the function is the definitive definition within the
580 program or whether it will be overridden by a stronger definition.
581 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
582 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]583
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]585 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
586 <tt>linkonce</tt> linkage, except that unreferenced globals with
587 <tt>weak</tt> linkage may not be discarded. This is used for globals that
588 are declared "weak" in C source code.</dd>
589
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]591 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
592 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
593 global scope.
594 Symbols with "<tt>common</tt>" linkage are merged in the same way as
595 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]596 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]597 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]598 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
599 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]600
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]601
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]602 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]603 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]604 pointer to array type. When two global variables with appending linkage
605 are linked together, the two global arrays are appended together. This is
606 the LLVM, typesafe, equivalent of having the system linker append together
607 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]608
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]610 <dd>The semantics of this linkage follow the ELF object file model: the symbol
611 is weak until linked, if not linked, the symbol becomes null instead of
612 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]613
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]614 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
615 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]616 <dd>Some languages allow differing globals to be merged, such as two functions
617 with different semantics. Other languages, such as <tt>C++</tt>, ensure
618 that only equivalent globals are ever merged (the "one definition rule" -
619 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
620 and <tt>weak_odr</tt> linkage types to indicate that the global will only
621 be merged with equivalent globals. These linkage types are otherwise the
622 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]623
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]624 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]625 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]626 visible, meaning that it participates in linkage and can be used to
627 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]628</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]629
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]630<p>The next two types of linkage are targeted for Microsoft Windows platform
631 only. They are designed to support importing (exporting) symbols from (to)
632 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]633
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]634<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]635 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]636 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]637 or variable via a global pointer to a pointer that is set up by the DLL
638 exporting the symbol. On Microsoft Windows targets, the pointer name is
639 formed by combining <code>__imp_</code> and the function or variable
640 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]641
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]642 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]643 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]644 pointer to a pointer in a DLL, so that it can be referenced with the
645 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
646 name is formed by combining <code>__imp_</code> and the function or
647 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]648</dl>
649
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]650<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
651 another module defined a "<tt>.LC0</tt>" variable and was linked with this
652 one, one of the two would be renamed, preventing a collision. Since
653 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
654 declarations), they are accessible outside of the current module.</p>
655
656<p>It is illegal for a function <i>declaration</i> to have any linkage type
657 other than "externally visible", <tt>dllimport</tt>
658 or <tt>extern_weak</tt>.</p>
659
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]660<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]661 or <tt>weak_odr</tt> linkages.</p>
662
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]663</div>
664
665<!-- ======================================================================= -->
666<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]667 <a name="callingconv">Calling Conventions</a>
668</div>
669
670<div class="doc_text">
671
672<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]673 and <a href="#i_invoke">invokes</a> can all have an optional calling
674 convention specified for the call. The calling convention of any pair of
675 dynamic caller/callee must match, or the behavior of the program is
676 undefined. The following calling conventions are supported by LLVM, and more
677 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]678
679<dl>
680 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]681 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]682 specified) matches the target C calling conventions. This calling
683 convention supports varargs function calls and tolerates some mismatch in
684 the declared prototype and implemented declaration of the function (as
685 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686
687 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]688 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]689 (e.g. by passing things in registers). This calling convention allows the
690 target to use whatever tricks it wants to produce fast code for the
691 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]692 (Application Binary Interface).
693 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
694 when this convention is used.</a> This calling convention does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]695 support varargs and requires the prototype of all callees to exactly match
696 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]697
698 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]699 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]700 as possible under the assumption that the call is not commonly executed.
701 As such, these calls often preserve all registers so that the call does
702 not break any live ranges in the caller side. This calling convention
703 does not support varargs and requires the prototype of all callees to
704 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]706 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]708 target-specific calling conventions to be used. Target specific calling
709 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]710</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]711
712<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]713 support Pascal conventions or any other well-known target-independent
714 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]715
716</div>
717
718<!-- ======================================================================= -->
719<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]720 <a name="visibility">Visibility Styles</a>
721</div>
722
723<div class="doc_text">
724
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]725<p>All Global Variables and Functions have one of the following visibility
726 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]727
728<dl>
729 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]730 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]731 that the declaration is visible to other modules and, in shared libraries,
732 means that the declared entity may be overridden. On Darwin, default
733 visibility means that the declaration is visible to other modules. Default
734 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]735
736 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]737 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]738 object if they are in the same shared object. Usually, hidden visibility
739 indicates that the symbol will not be placed into the dynamic symbol
740 table, so no other module (executable or shared library) can reference it
741 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]742
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]743 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]744 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]745 the dynamic symbol table, but that references within the defining module
746 will bind to the local symbol. That is, the symbol cannot be overridden by
747 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]748</dl>
749
750</div>
751
752<!-- ======================================================================= -->
753<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]754 <a name="namedtypes">Named Types</a>
755</div>
756
757<div class="doc_text">
758
759<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]760 it easier to read the IR and make the IR more condensed (particularly when
761 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]762
763<div class="doc_code">
764<pre>
765%mytype = type { %mytype*, i32 }
766</pre>
767</div>
768
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]769<p>You may give a name to any <a href="#typesystem">type</a> except
770 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
771 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]772
773<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]774 and that you can therefore specify multiple names for the same type. This
775 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
776 uses structural typing, the name is not part of the type. When printing out
777 LLVM IR, the printer will pick <em>one name</em> to render all types of a
778 particular shape. This means that if you have code where two different
779 source types end up having the same LLVM type, that the dumper will sometimes
780 print the "wrong" or unexpected type. This is an important design point and
781 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]782
783</div>
784
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]785<!-- ======================================================================= -->
786<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]787 <a name="globalvars">Global Variables</a>
788</div>
789
790<div class="doc_text">
791
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]792<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]793 instead of run-time. Global variables may optionally be initialized, may
794 have an explicit section to be placed in, and may have an optional explicit
795 alignment specified. A variable may be defined as "thread_local", which
796 means that it will not be shared by threads (each thread will have a
797 separated copy of the variable). A variable may be defined as a global
798 "constant," which indicates that the contents of the variable
799 will <b>never</b> be modified (enabling better optimization, allowing the
800 global data to be placed in the read-only section of an executable, etc).
801 Note that variables that need runtime initialization cannot be marked
802 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]803
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]804<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
805 constant, even if the final definition of the global is not. This capability
806 can be used to enable slightly better optimization of the program, but
807 requires the language definition to guarantee that optimizations based on the
808 'constantness' are valid for the translation units that do not include the
809 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]810
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]811<p>As SSA values, global variables define pointer values that are in scope
812 (i.e. they dominate) all basic blocks in the program. Global variables
813 always define a pointer to their "content" type because they describe a
814 region of memory, and all memory objects in LLVM are accessed through
815 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]816
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]817<p>A global variable may be declared to reside in a target-specific numbered
818 address space. For targets that support them, address spaces may affect how
819 optimizations are performed and/or what target instructions are used to
820 access the variable. The default address space is zero. The address space
821 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]822
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]823<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]824 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]825
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]826<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]827 the alignment is set to zero, the alignment of the global is set by the
828 target to whatever it feels convenient. If an explicit alignment is
829 specified, the global is forced to have at least that much alignment. All
830 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]831
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]832<p>For example, the following defines a global in a numbered address space with
833 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]834
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]835<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]836<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]837@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]838</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]839</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]840
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]841</div>
842
843
844<!-- ======================================================================= -->
845<div class="doc_subsection">
846 <a name="functionstructure">Functions</a>
847</div>
848
849<div class="doc_text">
850
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]851<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]852 optional <a href="#linkage">linkage type</a>, an optional
853 <a href="#visibility">visibility style</a>, an optional
854 <a href="#callingconv">calling convention</a>, a return type, an optional
855 <a href="#paramattrs">parameter attribute</a> for the return type, a function
856 name, a (possibly empty) argument list (each with optional
857 <a href="#paramattrs">parameter attributes</a>), optional
858 <a href="#fnattrs">function attributes</a>, an optional section, an optional
859 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
860 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]861
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]862<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
863 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]864 <a href="#visibility">visibility style</a>, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]865 <a href="#callingconv">calling convention</a>, a return type, an optional
866 <a href="#paramattrs">parameter attribute</a> for the return type, a function
867 name, a possibly empty list of arguments, an optional alignment, and an
868 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]869
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]870<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]871 (Control Flow Graph) for the function. Each basic block may optionally start
872 with a label (giving the basic block a symbol table entry), contains a list
873 of instructions, and ends with a <a href="#terminators">terminator</a>
874 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]875
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]876<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]877 executed on entrance to the function, and it is not allowed to have
878 predecessor basic blocks (i.e. there can not be any branches to the entry
879 block of a function). Because the block can have no predecessors, it also
880 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]881
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]882<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]883 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]884
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]885<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]886 the alignment is set to zero, the alignment of the function is set by the
887 target to whatever it feels convenient. If an explicit alignment is
888 specified, the function is forced to have at least that much alignment. All
889 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]890
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]891<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]892<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]893<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]894define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]895 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
896 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
897 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
898 [<a href="#gc">gc</a>] { ... }
899</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]900</div>
901
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]902</div>
903
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]904<!-- ======================================================================= -->
905<div class="doc_subsection">
906 <a name="aliasstructure">Aliases</a>
907</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]908
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]909<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]910
911<p>Aliases act as "second name" for the aliasee value (which can be either
912 function, global variable, another alias or bitcast of global value). Aliases
913 may have an optional <a href="#linkage">linkage type</a>, and an
914 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]915
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]916<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]917<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]918<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]919@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]920</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]921</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]922
923</div>
924
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]925<!-- ======================================================================= -->
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]926<div class="doc_subsection">
927 <a name="namedmetadatastructure">Named Metadata</a>
928</div>
929
930<div class="doc_text">
931
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]932<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
933 nodes</a> (but not metadata strings) and null are the only valid operands for
934 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]935
936<h5>Syntax:</h5>
937<div class="doc_code">
938<pre>
939!1 = metadata !{metadata !"one"}
940!name = !{null, !1}
941</pre>
942</div>
943
944</div>
945
946<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]947<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]948
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]949<div class="doc_text">
950
951<p>The return type and each parameter of a function type may have a set of
952 <i>parameter attributes</i> associated with them. Parameter attributes are
953 used to communicate additional information about the result or parameters of
954 a function. Parameter attributes are considered to be part of the function,
955 not of the function type, so functions with different parameter attributes
956 can have the same function type.</p>
957
958<p>Parameter attributes are simple keywords that follow the type specified. If
959 multiple parameter attributes are needed, they are space separated. For
960 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]961
962<div class="doc_code">
963<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]964declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]965declare i32 @atoi(i8 zeroext)
966declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]967</pre>
968</div>
969
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]970<p>Note that any attributes for the function result (<tt>nounwind</tt>,
971 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]972
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]973<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]974
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]975<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]976 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates to the code generator that the parameter or return value
978 should be zero-extended to a 32-bit value by the caller (for a parameter)
979 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]980
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]981 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]982 <dd>This indicates to the code generator that the parameter or return value
983 should be sign-extended to a 32-bit value by the caller (for a parameter)
984 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]985
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]986 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]987 <dd>This indicates that this parameter or return value should be treated in a
988 special target-dependent fashion during while emitting code for a function
989 call or return (usually, by putting it in a register as opposed to memory,
990 though some targets use it to distinguish between two different kinds of
991 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]992
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]993 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]994 <dd>This indicates that the pointer parameter should really be passed by value
995 to the function. The attribute implies that a hidden copy of the pointee
996 is made between the caller and the callee, so the callee is unable to
997 modify the value in the callee. This attribute is only valid on LLVM
998 pointer arguments. It is generally used to pass structs and arrays by
999 value, but is also valid on pointers to scalars. The copy is considered
1000 to belong to the caller not the callee (for example,
1001 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1002 <tt>byval</tt> parameters). This is not a valid attribute for return
1003 values. The byval attribute also supports specifying an alignment with
1004 the align attribute. This has a target-specific effect on the code
1005 generator that usually indicates a desired alignment for the synthesized
1006 stack slot.</dd>
1007
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1008 <dt><tt><b>sret</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1009 <dd>This indicates that the pointer parameter specifies the address of a
1010 structure that is the return value of the function in the source program.
1011 This pointer must be guaranteed by the caller to be valid: loads and
1012 stores to the structure may be assumed by the callee to not to trap. This
1013 may only be applied to the first parameter. This is not a valid attribute
1014 for return values. </dd>
1015
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1016 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1017 <dd>This indicates that the pointer does not alias any global or any other
1018 parameter. The caller is responsible for ensuring that this is the
1019 case. On a function return value, <tt>noalias</tt> additionally indicates
1020 that the pointer does not alias any other pointers visible to the
1021 caller. For further details, please see the discussion of the NoAlias
1022 response in
1023 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1024 analysis</a>.</dd>
1025
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates that the callee does not make any copies of the pointer
1028 that outlive the callee itself. This is not a valid attribute for return
1029 values.</dd>
1030
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>nest</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates that the pointer parameter can be excised using the
1033 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1034 attribute for return values.</dd>
1035</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1036
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1037</div>
1038
1039<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1040<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1041 <a name="gc">Garbage Collector Names</a>
1042</div>
1043
1044<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1045
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1046<p>Each function may specify a garbage collector name, which is simply a
1047 string:</p>
1048
1049<div class="doc_code">
1050<pre>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1051define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052</pre>
1053</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1054
1055<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1056 collector which will cause the compiler to alter its output in order to
1057 support the named garbage collection algorithm.</p>
1058
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1059</div>
1060
1061<!-- ======================================================================= -->
1062<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1063 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1064</div>
1065
1066<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1067
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068<p>Function attributes are set to communicate additional information about a
1069 function. Function attributes are considered to be part of the function, not
1070 of the function type, so functions with different parameter attributes can
1071 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1072
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1073<p>Function attributes are simple keywords that follow the type specified. If
1074 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1075
1076<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1077<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1078define void @f() noinline { ... }
1079define void @f() alwaysinline { ... }
1080define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1081define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1082</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1083</div>
1084
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1085<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1086 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1087 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1088 the backend should forcibly align the stack pointer. Specify the
1089 desired alignment, which must be a power of two, in parentheses.
1090
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1091 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1092 <dd>This attribute indicates that the inliner should attempt to inline this
1093 function into callers whenever possible, ignoring any active inlining size
1094 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1095
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1096 <dt><tt><b>inlinehint</b></tt></dt>
1097 <dd>This attribute indicates that the source code contained a hint that inlining
1098 this function is desirable (such as the "inline" keyword in C/C++). It
1099 is just a hint; it imposes no requirements on the inliner.</dd>
1100
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1101 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1102 <dd>This attribute indicates that the inliner should never inline this
1103 function in any situation. This attribute may not be used together with
1104 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1105
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1106 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1107 <dd>This attribute suggests that optimization passes and code generator passes
1108 make choices that keep the code size of this function low, and otherwise
1109 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1110
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1111 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1112 <dd>This function attribute indicates that the function never returns
1113 normally. This produces undefined behavior at runtime if the function
1114 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1115
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1116 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1117 <dd>This function attribute indicates that the function never returns with an
1118 unwind or exceptional control flow. If the function does unwind, its
1119 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1120
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1121 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1122 <dd>This attribute indicates that the function computes its result (or decides
1123 to unwind an exception) based strictly on its arguments, without
1124 dereferencing any pointer arguments or otherwise accessing any mutable
1125 state (e.g. memory, control registers, etc) visible to caller functions.
1126 It does not write through any pointer arguments
1127 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1128 changes any state visible to callers. This means that it cannot unwind
1129 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1130 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1131
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1132 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1133 <dd>This attribute indicates that the function does not write through any
1134 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1135 arguments) or otherwise modify any state (e.g. memory, control registers,
1136 etc) visible to caller functions. It may dereference pointer arguments
1137 and read state that may be set in the caller. A readonly function always
1138 returns the same value (or unwinds an exception identically) when called
1139 with the same set of arguments and global state. It cannot unwind an
1140 exception by calling the <tt>C++</tt> exception throwing methods, but may
1141 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1142
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1143 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1144 <dd>This attribute indicates that the function should emit a stack smashing
1145 protector. It is in the form of a "canary"&mdash;a random value placed on
1146 the stack before the local variables that's checked upon return from the
1147 function to see if it has been overwritten. A heuristic is used to
1148 determine if a function needs stack protectors or not.<br>
1149<br>
1150 If a function that has an <tt>ssp</tt> attribute is inlined into a
1151 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1152 function will have an <tt>ssp</tt> attribute.</dd>
1153
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the function should <em>always</em> emit a
1156 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1157 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1158<br>
1159 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1160 function that doesn't have an <tt>sspreq</tt> attribute or which has
1161 an <tt>ssp</tt> attribute, then the resulting function will have
1162 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1163
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1164 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1165 <dd>This attribute indicates that the code generator should not use a red
1166 zone, even if the target-specific ABI normally permits it.</dd>
1167
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1168 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1169 <dd>This attributes disables implicit floating point instructions.</dd>
1170
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1171 <dt><tt><b>naked</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1172 <dd>This attribute disables prologue / epilogue emission for the function.
1173 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1174</dl>
1175
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1176</div>
1177
1178<!-- ======================================================================= -->
1179<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1180 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1181</div>
1182
1183<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1184
1185<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1186 the GCC "file scope inline asm" blocks. These blocks are internally
1187 concatenated by LLVM and treated as a single unit, but may be separated in
1188 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1189
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1190<div class="doc_code">
1191<pre>
1192module asm "inline asm code goes here"
1193module asm "more can go here"
1194</pre>
1195</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1196
1197<p>The strings can contain any character by escaping non-printable characters.
1198 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]1199 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1200
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1201<p>The inline asm code is simply printed to the machine code .s file when
1202 assembly code is generated.</p>
1203
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1204</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1205
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1206<!-- ======================================================================= -->
1207<div class="doc_subsection">
1208 <a name="datalayout">Data Layout</a>
1209</div>
1210
1211<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1212
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1213<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1214 data is to be laid out in memory. The syntax for the data layout is
1215 simply:</p>
1216
1217<div class="doc_code">
1218<pre>
1219target datalayout = "<i>layout specification</i>"
1220</pre>
1221</div>
1222
1223<p>The <i>layout specification</i> consists of a list of specifications
1224 separated by the minus sign character ('-'). Each specification starts with
1225 a letter and may include other information after the letter to define some
1226 aspect of the data layout. The specifications accepted are as follows:</p>
1227
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1228<dl>
1229 <dt><tt>E</tt></dt>
1230 <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]1231 bits with the most significance have the lowest address location.</dd>
1232
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1233 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1234 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1235 the bits with the least significance have the lowest address
1236 location.</dd>
1237
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1238 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1239 <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]1240 <i>preferred</i> alignments. All sizes are in bits. Specifying
1241 the <i>pref</i> alignment is optional. If omitted, the
1242 preceding <tt>:</tt> should be omitted too.</dd>
1243
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1244 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1245 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1246 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1247
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1248 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1249 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1250 <i>size</i>.</dd>
1251
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1252 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1253 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1254 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1255 (double).</dd>
1256
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1257 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1258 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1259 <i>size</i>.</dd>
1260
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1261 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1262 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1263 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1264
1265 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1266 <dd>This specifies a set of native integer widths for the target CPU
1267 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1268 "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]1269 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1270 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1271</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1272
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1273<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1274 default set of specifications which are then (possibly) overriden by the
1275 specifications in the <tt>datalayout</tt> keyword. The default specifications
1276 are given in this list:</p>
1277
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1278<ul>
1279 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1280 <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]1281 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1282 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1283 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1284 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1285 <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]1286 alignment of 64-bits</li>
1287 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1288 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1289 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1290 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1291 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1292 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1293</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1294
1295<p>When LLVM is determining the alignment for a given type, it uses the
1296 following rules:</p>
1297
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1298<ol>
1299 <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]1300 specification is used.</li>
1301
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1302 <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]1303 smallest integer type that is larger than the bitwidth of the sought type
1304 is used. If none of the specifications are larger than the bitwidth then
1305 the the largest integer type is used. For example, given the default
1306 specifications above, the i7 type will use the alignment of i8 (next
1307 largest) while both i65 and i256 will use the alignment of i64 (largest
1308 specified).</li>
1309
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1310 <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]1311 largest vector type that is smaller than the sought vector type will be
1312 used as a fall back. This happens because &lt;128 x double&gt; can be
1313 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1314</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1315
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1316</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1317
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1318<!-- ======================================================================= -->
1319<div class="doc_subsection">
1320 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1321</div>
1322
1323<div class="doc_text">
1324
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1325<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1326with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1327is undefined. Pointer values are associated with address ranges
1328according to the following rules:</p>
1329
1330<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1331 <li>A pointer value formed from a
1332 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1333 is associated with the addresses associated with the first operand
1334 of the <tt>getelementptr</tt>.</li>
1335 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1336 range of the variable's storage.</li>
1337 <li>The result value of an allocation instruction is associated with
1338 the address range of the allocated storage.</li>
1339 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1340 no address.</li>
1341 <li>A pointer value formed by an
1342 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1343 address ranges of all pointer values that contribute (directly or
1344 indirectly) to the computation of the pointer's value.</li>
1345 <li>The result value of a
1346 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1347 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1348 <li>An integer constant other than zero or a pointer value returned
1349 from a function not defined within LLVM may be associated with address
1350 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1351 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1352 allocated by mechanisms provided by LLVM.</li>
1353 </ul>
1354
1355<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1356<tt><a href="#i_load">load</a></tt> merely indicates the size and
1357alignment of the memory from which to load, as well as the
1358interpretation of the value. The first operand of a
1359<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1360and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1361
1362<p>Consequently, type-based alias analysis, aka TBAA, aka
1363<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1364LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1365additional information which specialized optimization passes may use
1366to implement type-based alias analysis.</p>
1367
1368</div>
1369
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1370<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1371<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1372<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1373
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1374<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1376<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1377 intermediate representation. Being typed enables a number of optimizations
1378 to be performed on the intermediate representation directly, without having
1379 to do extra analyses on the side before the transformation. A strong type
1380 system makes it easier to read the generated code and enables novel analyses
1381 and transformations that are not feasible to perform on normal three address
1382 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1383
1384</div>
1385
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1386<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1387<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1388Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1389
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1390<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1391
1392<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1393
1394<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1395 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1396 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1397 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1398 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1399 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1400 </tr>
1401 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1402 <td><a href="#t_floating">floating point</a></td>
1403 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1404 </tr>
1405 <tr>
1406 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1407 <td><a href="#t_integer">integer</a>,
1408 <a href="#t_floating">floating point</a>,
1409 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1410 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1411 <a href="#t_struct">structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1412 <a href="#t_union">union</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1413 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1414 <a href="#t_label">label</a>,
1415 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1416 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1417 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1418 <tr>
1419 <td><a href="#t_primitive">primitive</a></td>
1420 <td><a href="#t_label">label</a>,
1421 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1422 <a href="#t_floating">floating point</a>,
1423 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1424 </tr>
1425 <tr>
1426 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1427 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1428 <a href="#t_function">function</a>,
1429 <a href="#t_pointer">pointer</a>,
1430 <a href="#t_struct">structure</a>,
1431 <a href="#t_pstruct">packed structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1432 <a href="#t_union">union</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1433 <a href="#t_vector">vector</a>,
1434 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1435 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1436 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1437 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1438</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1439
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1440<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1441 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1442 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1443
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1444</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1446<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1447<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1448
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1449<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1450
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1451<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1452 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1453
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1454</div>
1455
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1456<!-- _______________________________________________________________________ -->
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1457<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1458
1459<div class="doc_text">
1460
1461<h5>Overview:</h5>
1462<p>The integer type is a very simple type that simply specifies an arbitrary
1463 bit width for the integer type desired. Any bit width from 1 bit to
1464 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1465
1466<h5>Syntax:</h5>
1467<pre>
1468 iN
1469</pre>
1470
1471<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1472 value.</p>
1473
1474<h5>Examples:</h5>
1475<table class="layout">
1476 <tr class="layout">
1477 <td class="left"><tt>i1</tt></td>
1478 <td class="left">a single-bit integer.</td>
1479 </tr>
1480 <tr class="layout">
1481 <td class="left"><tt>i32</tt></td>
1482 <td class="left">a 32-bit integer.</td>
1483 </tr>
1484 <tr class="layout">
1485 <td class="left"><tt>i1942652</tt></td>
1486 <td class="left">a really big integer of over 1 million bits.</td>
1487 </tr>
1488</table>
1489
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1490</div>
1491
1492<!-- _______________________________________________________________________ -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1493<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1494
1495<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1496
1497<table>
1498 <tbody>
1499 <tr><th>Type</th><th>Description</th></tr>
1500 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1501 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1502 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1503 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1504 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1505 </tbody>
1506</table>
1507
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1508</div>
1509
1510<!-- _______________________________________________________________________ -->
1511<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1512
1513<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1514
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1515<h5>Overview:</h5>
1516<p>The void type does not represent any value and has no size.</p>
1517
1518<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1519<pre>
1520 void
1521</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1522
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1523</div>
1524
1525<!-- _______________________________________________________________________ -->
1526<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1527
1528<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1529
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1530<h5>Overview:</h5>
1531<p>The label type represents code labels.</p>
1532
1533<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1534<pre>
1535 label
1536</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1537
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1538</div>
1539
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1540<!-- _______________________________________________________________________ -->
1541<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1542
1543<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1544
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1545<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1546<p>The metadata type represents embedded metadata. No derived types may be
1547 created from metadata except for <a href="#t_function">function</a>
1548 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1549
1550<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1551<pre>
1552 metadata
1553</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1554
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1555</div>
1556
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1557
1558<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1559<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1560
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1561<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1562
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1563<p>The real power in LLVM comes from the derived types in the system. This is
1564 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1565 useful types. Each of these types contain one or more element types which
1566 may be a primitive type, or another derived type. For example, it is
1567 possible to have a two dimensional array, using an array as the element type
1568 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1569
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1570
1571</div>
1572
1573<!-- _______________________________________________________________________ -->
1574<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1575
1576<div class="doc_text">
1577
1578<p>Aggregate Types are a subset of derived types that can contain multiple
1579 member types. <a href="#t_array">Arrays</a>,
1580 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1581 <a href="#t_union">unions</a> are aggregate types.</p>
1582
1583</div>
1584
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1585</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1586
1587<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1588<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1589
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1590<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1591
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1592<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1593<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1594 sequentially in memory. The array type requires a size (number of elements)
1595 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1596
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1597<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1598<pre>
1599 [&lt;# elements&gt; x &lt;elementtype&gt;]
1600</pre>
1601
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1602<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1603 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1604
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1605<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1606<table class="layout">
1607 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1608 <td class="left"><tt>[40 x i32]</tt></td>
1609 <td class="left">Array of 40 32-bit integer values.</td>
1610 </tr>
1611 <tr class="layout">
1612 <td class="left"><tt>[41 x i32]</tt></td>
1613 <td class="left">Array of 41 32-bit integer values.</td>
1614 </tr>
1615 <tr class="layout">
1616 <td class="left"><tt>[4 x i8]</tt></td>
1617 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1618 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1619</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1620<p>Here are some examples of multidimensional arrays:</p>
1621<table class="layout">
1622 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1623 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1624 <td class="left">3x4 array of 32-bit integer values.</td>
1625 </tr>
1626 <tr class="layout">
1627 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1628 <td class="left">12x10 array of single precision floating point values.</td>
1629 </tr>
1630 <tr class="layout">
1631 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1632 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1633 </tr>
1634</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1635
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1636<p>There is no restriction on indexing beyond the end of the array implied by
1637 a static type (though there are restrictions on indexing beyond the bounds
1638 of an allocated object in some cases). This means that single-dimension
1639 'variable sized array' addressing can be implemented in LLVM with a zero
1640 length array type. An implementation of 'pascal style arrays' in LLVM could
1641 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1642
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1643</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1644
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1645<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1646<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1647
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1648<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1649
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1650<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1651<p>The function type can be thought of as a function signature. It consists of
1652 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]1653 function type is a scalar type, a void type, a struct type, or a union
1654 type. If the return type is a struct type then all struct elements must be
1655 of first class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1656
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1657<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1658<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1659 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1660</pre>
1661
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1662<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]1663 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1664 which indicates that the function takes a variable number of arguments.
1665 Variable argument functions can access their arguments with
1666 the <a href="#int_varargs">variable argument handling intrinsic</a>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1667 functions. '<tt>&lt;returntype&gt;</tt>' is a any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1668 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1669
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1670<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1671<table class="layout">
1672 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1673 <td class="left"><tt>i32 (i32)</tt></td>
1674 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1675 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1676 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1677 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1678 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1679 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1680 an <tt>i16</tt> that should be sign extended and a
1681 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1682 <tt>float</tt>.
1683 </td>
1684 </tr><tr class="layout">
1685 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1686 <td class="left">A vararg function that takes at least one
1687 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1688 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1689 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1690 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1691 </tr><tr class="layout">
1692 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1693 <td class="left">A function taking an <tt>i32</tt>, returning a
1694 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1695 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1696 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1697</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1698
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1699</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1700
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1701<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1702<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1703
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1704<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1705
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1706<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1707<p>The structure type is used to represent a collection of data members together
1708 in memory. The packing of the field types is defined to match the ABI of the
1709 underlying processor. The elements of a structure may be any type that has a
1710 size.</p>
1711
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1712<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1713 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1714 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1715 Structures in registers are accessed using the
1716 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1717 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1718<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1719<pre>
1720 { &lt;type list&gt; }
1721</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1722
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1723<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1724<table class="layout">
1725 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1726 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1727 <td class="left">A triple of three <tt>i32</tt> values</td>
1728 </tr><tr class="layout">
1729 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1730 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1731 second element is a <a href="#t_pointer">pointer</a> to a
1732 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1733 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1734 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1735</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1736
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1737</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1738
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1739<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1740<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1741</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1742
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1743<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1744
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1745<h5>Overview:</h5>
1746<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1747 together in memory. There is no padding between fields. Further, the
1748 alignment of a packed structure is 1 byte. The elements of a packed
1749 structure may be any type that has a size.</p>
1750
1751<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1752 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1753 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1754
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1755<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1756<pre>
1757 &lt; { &lt;type list&gt; } &gt;
1758</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1759
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1760<h5>Examples:</h5>
1761<table class="layout">
1762 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1763 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1764 <td class="left">A triple of three <tt>i32</tt> values</td>
1765 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1766 <td class="left">
1767<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1768 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1769 second element is a <a href="#t_pointer">pointer</a> to a
1770 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1771 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1772 </tr>
1773</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1774
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1775</div>
1776
1777<!-- _______________________________________________________________________ -->
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1778<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1779
1780<div class="doc_text">
1781
1782<h5>Overview:</h5>
1783<p>A union type describes an object with size and alignment suitable for
1784 an object of any one of a given set of types (also known as an "untagged"
1785 union). It is similar in concept and usage to a
1786 <a href="#t_struct">struct</a>, except that all members of the union
1787 have an offset of zero. The elements of a union may be any type that has a
1788 size. Unions must have at least one member - empty unions are not allowed.
1789 </p>
1790
1791<p>The size of the union as a whole will be the size of its largest member,
1792 and the alignment requirements of the union as a whole will be the largest
1793 alignment requirement of any member.</p>
1794
Dan Gohman2eddfef2010-02-25 16:51:31 +0000[diff] [blame]1795<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]1796 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1797 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1798 Since all members are at offset zero, the getelementptr instruction does
1799 not affect the address, only the type of the resulting pointer.</p>
1800
1801<h5>Syntax:</h5>
1802<pre>
1803 union { &lt;type list&gt; }
1804</pre>
1805
1806<h5>Examples:</h5>
1807<table class="layout">
1808 <tr class="layout">
1809 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1810 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1811 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1812 </tr><tr class="layout">
1813 <td class="left">
1814 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1815 <td class="left">A union, where the first element is a <tt>float</tt> and the
1816 second element is a <a href="#t_pointer">pointer</a> to a
1817 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1818 an <tt>i32</tt>.</td>
1819 </tr>
1820</table>
1821
1822</div>
1823
1824<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1825<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1826
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1827<div class="doc_text">
1828
1829<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1830<p>The pointer type is used to specify memory locations.
1831 Pointers are commonly used to reference objects in memory.</p>
1832
1833<p>Pointer types may have an optional address space attribute defining the
1834 numbered address space where the pointed-to object resides. The default
1835 address space is number zero. The semantics of non-zero address
1836 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1837
1838<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1839 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1840
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1841<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1842<pre>
1843 &lt;type&gt; *
1844</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1845
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1846<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1847<table class="layout">
1848 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1849 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1850 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1851 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1852 </tr>
1853 <tr class="layout">
1854 <td class="left"><tt>i32 (i32 *) *</tt></td>
1855 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1856 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1857 <tt>i32</tt>.</td>
1858 </tr>
1859 <tr class="layout">
1860 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1861 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1862 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1863 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1864</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1865
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1866</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1867
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1868<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1869<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1870
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1871<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1872
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1873<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1874<p>A vector type is a simple derived type that represents a vector of elements.
1875 Vector types are used when multiple primitive data are operated in parallel
1876 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1877 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1878 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1879
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1880<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1881<pre>
1882 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1883</pre>
1884
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1885<p>The number of elements is a constant integer value; elementtype may be any
1886 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1887
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1888<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1889<table class="layout">
1890 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1891 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1892 <td class="left">Vector of 4 32-bit integer values.</td>
1893 </tr>
1894 <tr class="layout">
1895 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1896 <td class="left">Vector of 8 32-bit floating-point values.</td>
1897 </tr>
1898 <tr class="layout">
1899 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1900 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1901 </tr>
1902</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1903
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1904</div>
1905
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1906<!-- _______________________________________________________________________ -->
1907<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1908<div class="doc_text">
1909
1910<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1911<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1912 corresponds (for example) to the C notion of a forward declared structure
1913 type. In LLVM, opaque types can eventually be resolved to any type (not just
1914 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1915
1916<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1917<pre>
1918 opaque
1919</pre>
1920
1921<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1922<table class="layout">
1923 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1924 <td class="left"><tt>opaque</tt></td>
1925 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1926 </tr>
1927</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1928
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1929</div>
1930
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1931<!-- ======================================================================= -->
1932<div class="doc_subsection">
1933 <a name="t_uprefs">Type Up-references</a>
1934</div>
1935
1936<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1938<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1939<p>An "up reference" allows you to refer to a lexically enclosing type without
1940 requiring it to have a name. For instance, a structure declaration may
1941 contain a pointer to any of the types it is lexically a member of. Example
1942 of up references (with their equivalent as named type declarations)
1943 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1944
1945<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1946 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1947 { \2 }* %y = type { %y }*
1948 \1* %z = type %z*
1949</pre>
1950
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1951<p>An up reference is needed by the asmprinter for printing out cyclic types
1952 when there is no declared name for a type in the cycle. Because the
1953 asmprinter does not want to print out an infinite type string, it needs a
1954 syntax to handle recursive types that have no names (all names are optional
1955 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1956
1957<h5>Syntax:</h5>
1958<pre>
1959 \&lt;level&gt;
1960</pre>
1961
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1962<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]1963
1964<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1965<table class="layout">
1966 <tr class="layout">
1967 <td class="left"><tt>\1*</tt></td>
1968 <td class="left">Self-referential pointer.</td>
1969 </tr>
1970 <tr class="layout">
1971 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1972 <td class="left">Recursive structure where the upref refers to the out-most
1973 structure.</td>
1974 </tr>
1975</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1976
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1977</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1978
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1979<!-- *********************************************************************** -->
1980<div class="doc_section"> <a name="constants">Constants</a> </div>
1981<!-- *********************************************************************** -->
1982
1983<div class="doc_text">
1984
1985<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1986 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1987
1988</div>
1989
1990<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1991<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1992
1993<div class="doc_text">
1994
1995<dl>
1996 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1997 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1998 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1999
2000 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2001 <dd>Standard integers (such as '4') are constants of
2002 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2003 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2004
2005 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2006 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2007 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2008 notation (see below). The assembler requires the exact decimal value of a
2009 floating-point constant. For example, the assembler accepts 1.25 but
2010 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2011 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2012
2013 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2014 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2015 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2016</dl>
2017
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2018<p>The one non-intuitive notation for constants is the hexadecimal form of
2019 floating point constants. For example, the form '<tt>double
2020 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2021 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2022 constants are required (and the only time that they are generated by the
2023 disassembler) is when a floating point constant must be emitted but it cannot
2024 be represented as a decimal floating point number in a reasonable number of
2025 digits. For example, NaN's, infinities, and other special values are
2026 represented in their IEEE hexadecimal format so that assembly and disassembly
2027 do not cause any bits to change in the constants.</p>
2028
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2029<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2030 represented using the 16-digit form shown above (which matches the IEEE754
2031 representation for double); float values must, however, be exactly
2032 representable as IEE754 single precision. Hexadecimal format is always used
2033 for long double, and there are three forms of long double. The 80-bit format
2034 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2035 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2036 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2037 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2038 currently supported target uses this format. Long doubles will only work if
2039 they match the long double format on your target. All hexadecimal formats
2040 are big-endian (sign bit at the left).</p>
2041
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2042</div>
2043
2044<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2045<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2046<a name="aggregateconstants"></a> <!-- old anchor -->
2047<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2048</div>
2049
2050<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2051
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2052<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2053 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2054
2055<dl>
2056 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2057 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2058 type definitions (a comma separated list of elements, surrounded by braces
2059 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2060 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2061 Structure constants must have <a href="#t_struct">structure type</a>, and
2062 the number and types of elements must match those specified by the
2063 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2064
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2065 <dt><b>Union constants</b></dt>
2066 <dd>Union constants are represented with notation similar to a structure with
2067 a single element - that is, a single typed element surrounded
2068 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2069 <a href="#t_union">union type</a> can be initialized with a single-element
2070 struct as long as the type of the struct element matches the type of
2071 one of the union members.</dd>
2072
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2073 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2074 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2075 definitions (a comma separated list of elements, surrounded by square
2076 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2077 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2078 the number and types of elements must match those specified by the
2079 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2080
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2081 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2082 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2083 definitions (a comma separated list of elements, surrounded by
2084 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2085 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2086 have <a href="#t_vector">vector type</a>, and the number and types of
2087 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2088
2089 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2090 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2091 value to zero of <em>any</em> type, including scalar and
2092 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2093 This is often used to avoid having to print large zero initializers
2094 (e.g. for large arrays) and is always exactly equivalent to using explicit
2095 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2096
2097 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2098 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2099 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2100 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2101 be interpreted as part of the instruction stream, metadata is a place to
2102 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2103</dl>
2104
2105</div>
2106
2107<!-- ======================================================================= -->
2108<div class="doc_subsection">
2109 <a name="globalconstants">Global Variable and Function Addresses</a>
2110</div>
2111
2112<div class="doc_text">
2113
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2114<p>The addresses of <a href="#globalvars">global variables</a>
2115 and <a href="#functionstructure">functions</a> are always implicitly valid
2116 (link-time) constants. These constants are explicitly referenced when
2117 the <a href="#identifiers">identifier for the global</a> is used and always
2118 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2119 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2120
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2121<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2122<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2123@X = global i32 17
2124@Y = global i32 42
2125@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2126</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2127</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2128
2129</div>
2130
2131<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2132<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2133<div class="doc_text">
2134
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2135<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]2136 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2137 Undefined values may be of any type (other than label or void) and be used
2138 anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2139
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2140<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2141 program is well defined no matter what value is used. This gives the
2142 compiler more freedom to optimize. Here are some examples of (potentially
2143 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2144
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2145
2146<div class="doc_code">
2147<pre>
2148 %A = add %X, undef
2149 %B = sub %X, undef
2150 %C = xor %X, undef
2151Safe:
2152 %A = undef
2153 %B = undef
2154 %C = undef
2155</pre>
2156</div>
2157
2158<p>This is safe because all of the output bits are affected by the undef bits.
2159Any output bit can have a zero or one depending on the input bits.</p>
2160
2161<div class="doc_code">
2162<pre>
2163 %A = or %X, undef
2164 %B = and %X, undef
2165Safe:
2166 %A = -1
2167 %B = 0
2168Unsafe:
2169 %A = undef
2170 %B = undef
2171</pre>
2172</div>
2173
2174<p>These logical operations have bits that are not always affected by the input.
2175For example, if "%X" has a zero bit, then the output of the 'and' operation will
2176always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2177such, 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]2178However, it is safe to assume that all bits of the undef could be 0, and
2179optimize the and to 0. Likewise, it is safe to assume that all the bits of
2180the 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]2181-1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2182
2183<div class="doc_code">
2184<pre>
2185 %A = select undef, %X, %Y
2186 %B = select undef, 42, %Y
2187 %C = select %X, %Y, undef
2188Safe:
2189 %A = %X (or %Y)
2190 %B = 42 (or %Y)
2191 %C = %Y
2192Unsafe:
2193 %A = undef
2194 %B = undef
2195 %C = undef
2196</pre>
2197</div>
2198
2199<p>This set of examples show that undefined select (and conditional branch)
2200conditions can go "either way" but they have to come from one of the two
2201operands. In the %A example, if %X and %Y were both known to have a clear low
2202bit, then %A would have to have a cleared low bit. However, in the %C example,
2203the optimizer is allowed to assume that the undef operand could be the same as
2204%Y, allowing the whole select to be eliminated.</p>
2205
2206
2207<div class="doc_code">
2208<pre>
2209 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2210
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2211 %B = undef
2212 %C = xor %B, %B
2213
2214 %D = undef
2215 %E = icmp lt %D, 4
2216 %F = icmp gte %D, 4
2217
2218Safe:
2219 %A = undef
2220 %B = undef
2221 %C = undef
2222 %D = undef
2223 %E = undef
2224 %F = undef
2225</pre>
2226</div>
2227
2228<p>This example points out that two undef operands are not necessarily the same.
2229This can be surprising to people (and also matches C semantics) where they
2230assume that "X^X" is always zero, even if X is undef. This isn't true for a
2231number of reasons, but the short answer is that an undef "variable" can
2232arbitrarily change its value over its "live range". This is true because the
2233"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2234logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2235so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner349eb412009-09-08 15:13:16 +0000[diff] [blame]2236to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2237would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2238
2239<div class="doc_code">
2240<pre>
2241 %A = fdiv undef, %X
2242 %B = fdiv %X, undef
2243Safe:
2244 %A = undef
2245b: unreachable
2246</pre>
2247</div>
2248
2249<p>These examples show the crucial difference between an <em>undefined
2250value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2251allowed to have an arbitrary bit-pattern. This means that the %A operation
2252can be constant folded to undef because the undef could be an SNaN, and fdiv is
2253not (currently) defined on SNaN's. However, in the second example, we can make
2254a more aggressive assumption: because the undef is allowed to be an arbitrary
2255value, 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]2256has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2257does not execute at all. This allows us to delete the divide and all code after
2258it: since the undefined operation "can't happen", the optimizer can assume that
2259it occurs in dead code.
2260</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2261
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2262<div class="doc_code">
2263<pre>
2264a: store undef -> %X
2265b: store %X -> undef
2266Safe:
2267a: &lt;deleted&gt;
2268b: unreachable
2269</pre>
2270</div>
2271
2272<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2273can be assumed to not have any effect: we can assume that the value is
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2274overwritten with bits that happen to match what was already there. However, a
2275store "to" an undefined location could clobber arbitrary memory, therefore, it
2276has undefined behavior.</p>
2277
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2278</div>
2279
2280<!-- ======================================================================= -->
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2281<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2282 Blocks</a></div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2283<div class="doc_text">
2284
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2285<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2286
2287<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2288 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2289 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2290
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2291<p>This value only has defined behavior when used as an operand to the
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2292 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2293 against null. Pointer equality tests between labels addresses is undefined
2294 behavior - though, again, comparison against null is ok, and no label is
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2295 equal to the null pointer. This may also be passed around as an opaque
2296 pointer sized value as long as the bits are not inspected. This allows
Chris Lattner3fd77ce2009-10-27 21:44:20 +0000[diff] [blame]2297 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2298 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2299
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2300<p>Finally, some targets may provide defined semantics when
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2301 using the value as the operand to an inline assembly, but that is target
2302 specific.
2303 </p>
2304
2305</div>
2306
2307
2308<!-- ======================================================================= -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2309<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2310</div>
2311
2312<div class="doc_text">
2313
2314<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2315 to be used as constants. Constant expressions may be of
2316 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2317 operation that does not have side effects (e.g. load and call are not
2318 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2319
2320<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2321 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2322 <dd>Truncate a constant to another type. The bit size of CST must be larger
2323 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2324
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2325 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2326 <dd>Zero extend a constant to another type. The bit size of CST must be
2327 smaller or equal to the bit size of TYPE. Both types must be
2328 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2329
2330 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2331 <dd>Sign extend a constant to another type. The bit size of CST must be
2332 smaller or equal to the bit size of TYPE. Both types must be
2333 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2334
2335 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2336 <dd>Truncate a floating point constant to another floating point type. The
2337 size of CST must be larger than the size of TYPE. Both types must be
2338 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2339
2340 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2341 <dd>Floating point extend a constant to another type. The size of CST must be
2342 smaller or equal to the size of TYPE. Both types must be floating
2343 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2344
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2345 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2346 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2347 constant. TYPE must be a scalar or vector integer type. CST must be of
2348 scalar or vector floating point type. Both CST and TYPE must be scalars,
2349 or vectors of the same number of elements. If the value won't fit in the
2350 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2351
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2352 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2353 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2354 constant. TYPE must be a scalar or vector integer type. CST must be of
2355 scalar or vector floating point type. Both CST and TYPE must be scalars,
2356 or vectors of the same number of elements. If the value won't fit in the
2357 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2358
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2359 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2360 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2361 constant. TYPE must be a scalar or vector floating point type. CST must be
2362 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2363 vectors of the same number of elements. If the value won't fit in the
2364 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2365
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2366 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2367 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2368 constant. TYPE must be a scalar or vector floating point type. CST must be
2369 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2370 vectors of the same number of elements. If the value won't fit in the
2371 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2372
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2373 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2374 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2375 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2376 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2377 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2378
2379 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2380 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2381 type. CST must be of integer type. The CST value is zero extended,
2382 truncated, or unchanged to make it fit in a pointer size. This one is
2383 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2384
2385 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2386 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2387 are the same as those for the <a href="#i_bitcast">bitcast
2388 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2389
2390 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2391 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2392 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2393 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2394 instruction, the index list may have zero or more indexes, which are
2395 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2396
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2397 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2398 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2399
2400 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2401 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2402
2403 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2404 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2405
2406 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2407 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2408 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2409
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2410 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2411 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2412 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2413
2414 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2415 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2416 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2417
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2418 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2419 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2420 be any of the <a href="#binaryops">binary</a>
2421 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2422 on operands are the same as those for the corresponding instruction
2423 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2424</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2425
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2426</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2427
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2428<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2429<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2430<!-- *********************************************************************** -->
2431
2432<!-- ======================================================================= -->
2433<div class="doc_subsection">
2434<a name="inlineasm">Inline Assembler Expressions</a>
2435</div>
2436
2437<div class="doc_text">
2438
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2439<p>LLVM supports inline assembler expressions (as opposed
2440 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2441 a special value. This value represents the inline assembler as a string
2442 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2443 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2444 expression has side effects, and a flag indicating whether the function
2445 containing the asm needs to align its stack conservatively. An example
2446 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2447
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2448<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2449<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2450i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2451</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2452</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2453
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2454<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2455 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2456 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2457
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2458<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2459<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2460%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]2461</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2462</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2463
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2464<p>Inline asms with side effects not visible in the constraint list must be
2465 marked as having side effects. This is done through the use of the
2466 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2467
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2468<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2469<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2470call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2471</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2472</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2473
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2474<p>In some cases inline asms will contain code that will not work unless the
2475 stack is aligned in some way, such as calls or SSE instructions on x86,
2476 yet will not contain code that does that alignment within the asm.
2477 The compiler should make conservative assumptions about what the asm might
2478 contain and should generate its usual stack alignment code in the prologue
2479 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2480
2481<div class="doc_code">
2482<pre>
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2483call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2484</pre>
2485</div>
2486
2487<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2488 first.</p>
2489
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2490<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2491 documented here. Constraints on what can be done (e.g. duplication, moving,
2492 etc need to be documented). This is probably best done by reference to
2493 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2494
2495</div>
2496
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2497<!-- ======================================================================= -->
2498<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2499 Strings</a>
2500</div>
2501
2502<div class="doc_text">
2503
2504<p>LLVM IR allows metadata to be attached to instructions in the program that
2505 can convey extra information about the code to the optimizers and code
2506 generator. One example application of metadata is source-level debug
2507 information. There are two metadata primitives: strings and nodes. All
2508 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2509 preceding exclamation point ('<tt>!</tt>').</p>
2510
2511<p>A metadata string is a string surrounded by double quotes. It can contain
2512 any character by escaping non-printable characters with "\xx" where "xx" is
2513 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2514
2515<p>Metadata nodes are represented with notation similar to structure constants
2516 (a comma separated list of elements, surrounded by braces and preceded by an
2517 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2518 10}</tt>". Metadata nodes can have any values as their operand.</p>
2519
2520<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2521 metadata nodes, which can be looked up in the module symbol table. For
2522 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2523
2524</div>
2525
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2526
2527<!-- *********************************************************************** -->
2528<div class="doc_section">
2529 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2530</div>
2531<!-- *********************************************************************** -->
2532
2533<p>LLVM has a number of "magic" global variables that contain data that affect
2534code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2535of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2536section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2537by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2538
2539<!-- ======================================================================= -->
2540<div class="doc_subsection">
2541<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2542</div>
2543
2544<div class="doc_text">
2545
2546<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2547href="#linkage_appending">appending linkage</a>. This array contains a list of
2548pointers to global variables and functions which may optionally have a pointer
2549cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2550
2551<pre>
2552 @X = global i8 4
2553 @Y = global i32 123
2554
2555 @llvm.used = appending global [2 x i8*] [
2556 i8* @X,
2557 i8* bitcast (i32* @Y to i8*)
2558 ], section "llvm.metadata"
2559</pre>
2560
2561<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2562compiler, assembler, and linker are required to treat the symbol as if there is
2563a reference to the global that it cannot see. For example, if a variable has
2564internal linkage and no references other than that from the <tt>@llvm.used</tt>
2565list, it cannot be deleted. This is commonly used to represent references from
2566inline asms and other things the compiler cannot "see", and corresponds to
2567"attribute((used))" in GNU C.</p>
2568
2569<p>On some targets, the code generator must emit a directive to the assembler or
2570object file to prevent the assembler and linker from molesting the symbol.</p>
2571
2572</div>
2573
2574<!-- ======================================================================= -->
2575<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2576<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2577</div>
2578
2579<div class="doc_text">
2580
2581<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2582<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2583touching the symbol. On targets that support it, this allows an intelligent
2584linker to optimize references to the symbol without being impeded as it would be
2585by <tt>@llvm.used</tt>.</p>
2586
2587<p>This is a rare construct that should only be used in rare circumstances, and
2588should not be exposed to source languages.</p>
2589
2590</div>
2591
2592<!-- ======================================================================= -->
2593<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2594<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2595</div>
2596
2597<div class="doc_text">
2598
2599<p>TODO: Describe this.</p>
2600
2601</div>
2602
2603<!-- ======================================================================= -->
2604<div class="doc_subsection">
2605<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2606</div>
2607
2608<div class="doc_text">
2609
2610<p>TODO: Describe this.</p>
2611
2612</div>
2613
2614
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2615<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2616<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2617<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2618
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2619<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2620
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2621<p>The LLVM instruction set consists of several different classifications of
2622 instructions: <a href="#terminators">terminator
2623 instructions</a>, <a href="#binaryops">binary instructions</a>,
2624 <a href="#bitwiseops">bitwise binary instructions</a>,
2625 <a href="#memoryops">memory instructions</a>, and
2626 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2627
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2628</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2629
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2630<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2631<div class="doc_subsection"> <a name="terminators">Terminator
2632Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2633
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2634<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2635
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2636<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2637 in a program ends with a "Terminator" instruction, which indicates which
2638 block should be executed after the current block is finished. These
2639 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2640 control flow, not values (the one exception being the
2641 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2642
2643<p>There are six different terminator instructions: the
2644 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2645 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2646 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2647 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2648 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2649 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2650 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2651
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2652</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2653
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2654<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2655<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2656Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2657
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2658<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2659
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2660<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2661<pre>
2662 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]2663 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2664</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2665
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2666<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2667<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2668 a value) from a function back to the caller.</p>
2669
2670<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2671 value and then causes control flow, and one that just causes control flow to
2672 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2673
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2674<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2675<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2676 return value. The type of the return value must be a
2677 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2678
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2679<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2680 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2681 value or a return value with a type that does not match its type, or if it
2682 has a void return type and contains a '<tt>ret</tt>' instruction with a
2683 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2684
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2685<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2686<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2687 the calling function's context. If the caller is a
2688 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2689 instruction after the call. If the caller was an
2690 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2691 the beginning of the "normal" destination block. If the instruction returns
2692 a value, that value shall set the call or invoke instruction's return
2693 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2694
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2695<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2696<pre>
2697 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2698 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2699 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]2700</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2701
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2702</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2703<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2704<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2705
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2706<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2707
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2708<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2709<pre>
2710 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]2711</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2712
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2713<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2714<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2715 different basic block in the current function. There are two forms of this
2716 instruction, corresponding to a conditional branch and an unconditional
2717 branch.</p>
2718
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2719<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2720<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2721 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2722 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2723 target.</p>
2724
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2725<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2726<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2727 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2728 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2729 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2730
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2731<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2732<pre>
2733Test:
2734 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2735 br i1 %cond, label %IfEqual, label %IfUnequal
2736IfEqual:
2737 <a href="#i_ret">ret</a> i32 1
2738IfUnequal:
2739 <a href="#i_ret">ret</a> i32 0
2740</pre>
2741
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2742</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2743
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2744<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2745<div class="doc_subsubsection">
2746 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2747</div>
2748
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2749<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2750
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2751<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2752<pre>
2753 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2754</pre>
2755
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2756<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2757<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]2758 several different places. It is a generalization of the '<tt>br</tt>'
2759 instruction, allowing a branch to occur to one of many possible
2760 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2761
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2762<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2763<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2764 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2765 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2766 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2768<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2769<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2770 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2771 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2772 transferred to the corresponding destination; otherwise, control flow is
2773 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2774
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2775<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2776<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2777 <tt>switch</tt> instruction, this instruction may be code generated in
2778 different ways. For example, it could be generated as a series of chained
2779 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2780
2781<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2782<pre>
2783 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2784 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2785 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2786
2787 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2788 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2789
2790 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2791 switch i32 %val, label %otherwise [ i32 0, label %onzero
2792 i32 1, label %onone
2793 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2794</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2795
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2796</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2797
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2798
2799<!-- _______________________________________________________________________ -->
2800<div class="doc_subsubsection">
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2801 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2802</div>
2803
2804<div class="doc_text">
2805
2806<h5>Syntax:</h5>
2807<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2808 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]2809</pre>
2810
2811<h5>Overview:</h5>
2812
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2813<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2814 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2815 "<tt>address</tt>". Address must be derived from a <a
2816 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2817
2818<h5>Arguments:</h5>
2819
2820<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2821 rest of the arguments indicate the full set of possible destinations that the
2822 address may point to. Blocks are allowed to occur multiple times in the
2823 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2824
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2825<p>This destination list is required so that dataflow analysis has an accurate
2826 understanding of the CFG.</p>
2827
2828<h5>Semantics:</h5>
2829
2830<p>Control transfers to the block specified in the address argument. All
2831 possible destination blocks must be listed in the label list, otherwise this
2832 instruction has undefined behavior. This implies that jumps to labels
2833 defined in other functions have undefined behavior as well.</p>
2834
2835<h5>Implementation:</h5>
2836
2837<p>This is typically implemented with a jump through a register.</p>
2838
2839<h5>Example:</h5>
2840<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2841 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2842</pre>
2843
2844</div>
2845
2846
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2847<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2848<div class="doc_subsubsection">
2849 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2850</div>
2851
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2852<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2853
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2854<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2855<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2856 &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]2857 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2858</pre>
2859
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2860<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2861<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2862 function, with the possibility of control flow transfer to either the
2863 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2864 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2865 control flow will return to the "normal" label. If the callee (or any
2866 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2867 instruction, control is interrupted and continued at the dynamically nearest
2868 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2869
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2870<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2871<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2872
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2873<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2874 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2875 convention</a> the call should use. If none is specified, the call
2876 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2877
2878 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2879 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2880 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2881
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2882 <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]2883 function value being invoked. In most cases, this is a direct function
2884 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2885 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2886
2887 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2888 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2889
2890 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2891 signature argument types. If the function signature indicates the
2892 function accepts a variable number of arguments, the extra arguments can
2893 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2894
2895 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2896 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2897
2898 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2899 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2900
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2901 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2902 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2903 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2904</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2905
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2906<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2907<p>This instruction is designed to operate as a standard
2908 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2909 primary difference is that it establishes an association with a label, which
2910 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2911
2912<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2913 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2914 exception. Additionally, this is important for implementation of
2915 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2916
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2917<p>For the purposes of the SSA form, the definition of the value returned by the
2918 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2919 block to the "normal" label. If the callee unwinds then no return value is
2920 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2921
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]2922<p>Note that the code generator does not yet completely support unwind, and
2923that the invoke/unwind semantics are likely to change in future versions.</p>
2924
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2925<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2926<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2927 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2928 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2929 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2930 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2931</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2932
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2933</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2934
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2935<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2936
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2937<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2938Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2939
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2940<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2941
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2942<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2943<pre>
2944 unwind
2945</pre>
2946
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2947<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2948<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2949 at the first callee in the dynamic call stack which used
2950 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2951 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2952
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2953<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2954<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2955 immediately halt. The dynamic call stack is then searched for the
2956 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2957 Once found, execution continues at the "exceptional" destination block
2958 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2959 instruction in the dynamic call chain, undefined behavior results.</p>
2960
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]2961<p>Note that the code generator does not yet completely support unwind, and
2962that the invoke/unwind semantics are likely to change in future versions.</p>
2963
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2964</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2965
2966<!-- _______________________________________________________________________ -->
2967
2968<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2969Instruction</a> </div>
2970
2971<div class="doc_text">
2972
2973<h5>Syntax:</h5>
2974<pre>
2975 unreachable
2976</pre>
2977
2978<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2979<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2980 instruction is used to inform the optimizer that a particular portion of the
2981 code is not reachable. This can be used to indicate that the code after a
2982 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2983
2984<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2985<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2986
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2987</div>
2988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2989<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2990<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2991
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2992<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2993
2994<p>Binary operators are used to do most of the computation in a program. They
2995 require two operands of the same type, execute an operation on them, and
2996 produce a single value. The operands might represent multiple data, as is
2997 the case with the <a href="#t_vector">vector</a> data type. The result value
2998 has the same type as its operands.</p>
2999
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3000<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3001
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3002</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3003
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3004<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3005<div class="doc_subsubsection">
3006 <a name="i_add">'<tt>add</tt>' Instruction</a>
3007</div>
3008
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3009<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3010
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3011<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3012<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3013 &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]3014 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3015 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3016 &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]3017</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3018
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3019<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3020<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3021
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3022<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023<p>The two arguments to the '<tt>add</tt>' instruction must
3024 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3025 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3026
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3027<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3028<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3029
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3030<p>If the sum has unsigned overflow, the result returned is the mathematical
3031 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]3032
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3033<p>Because LLVM integers use a two's complement representation, this instruction
3034 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3035
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3036<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3037 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3038 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
3039 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3040
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3041<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3042<pre>
3043 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3044</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3045
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3046</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3048<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3049<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3050 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3051</div>
3052
3053<div class="doc_text">
3054
3055<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3056<pre>
3057 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3058</pre>
3059
3060<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3061<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3062
3063<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3064<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3065 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3066 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3067
3068<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3069<p>The value produced is the floating point sum of the two operands.</p>
3070
3071<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3072<pre>
3073 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3074</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3075
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3076</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3077
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3078<!-- _______________________________________________________________________ -->
3079<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3080 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3081</div>
3082
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3083<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3084
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3085<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3086<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3087 &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]3088 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3089 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3090 &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]3091</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3092
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3093<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3094<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3095 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3096
3097<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3098 '<tt>neg</tt>' instruction present in most other intermediate
3099 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3100
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3101<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3102<p>The two arguments to the '<tt>sub</tt>' instruction must
3103 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3104 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3105
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3106<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3107<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3108
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3109<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3110 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3111 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3112
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3113<p>Because LLVM integers use a two's complement representation, this instruction
3114 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3115
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3116<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3117 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3118 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
3119 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3120
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3121<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3122<pre>
3123 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3124 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3125</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3126
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3127</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3128
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3129<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3130<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3131 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3132</div>
3133
3134<div class="doc_text">
3135
3136<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3137<pre>
3138 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3139</pre>
3140
3141<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3142<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3143 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3144
3145<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3146 '<tt>fneg</tt>' instruction present in most other intermediate
3147 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3148
3149<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3150<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3151 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3152 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3153
3154<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3155<p>The value produced is the floating point difference of the two operands.</p>
3156
3157<h5>Example:</h5>
3158<pre>
3159 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3160 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3161</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3162
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3163</div>
3164
3165<!-- _______________________________________________________________________ -->
3166<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3167 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3168</div>
3169
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3170<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3171
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3172<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3173<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3174 &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]3175 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3176 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3177 &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]3178</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3179
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3180<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3181<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3182
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3183<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3184<p>The two arguments to the '<tt>mul</tt>' instruction must
3185 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3186 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3187
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3188<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3189<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3190
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3191<p>If the result of the multiplication has unsigned overflow, the result
3192 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3193 width of the result.</p>
3194
3195<p>Because LLVM integers use a two's complement representation, and the result
3196 is the same width as the operands, this instruction returns the correct
3197 result for both signed and unsigned integers. If a full product
3198 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3199 be sign-extended or zero-extended as appropriate to the width of the full
3200 product.</p>
3201
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3202<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3203 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3204 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3205 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3206
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3207<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3208<pre>
3209 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3210</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3211
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3212</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3213
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3214<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3215<div class="doc_subsubsection">
3216 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3217</div>
3218
3219<div class="doc_text">
3220
3221<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3222<pre>
3223 &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]3224</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3225
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3226<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3227<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3228
3229<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3230<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3231 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3232 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3233
3234<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3235<p>The value produced is the floating point product of the two operands.</p>
3236
3237<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3238<pre>
3239 &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]3240</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3241
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3242</div>
3243
3244<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3245<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3246</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3247
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3248<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3249
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3250<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3251<pre>
3252 &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]3253</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3254
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3255<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3256<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3257
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3258<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3259<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3260 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3261 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3262
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3263<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3264<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3265
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3266<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3267 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3268
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3269<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3270
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3271<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3272<pre>
3273 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3274</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3275
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3276</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3277
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3278<!-- _______________________________________________________________________ -->
3279<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3280</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3281
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3282<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3283
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3284<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3285<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3286 &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]3287 &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]3288</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3289
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3290<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3291<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3292
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3293<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3294<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3295 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3296 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3297
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3298<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3299<p>The value produced is the signed integer quotient of the two operands rounded
3300 towards zero.</p>
3301
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3302<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3303 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3304
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3305<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3306 undefined behavior; this is a rare case, but can occur, for example, by doing
3307 a 32-bit division of -2147483648 by -1.</p>
3308
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3309<p>If the <tt>exact</tt> keyword is present, the result value of the
3310 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3311 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3312
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3313<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3314<pre>
3315 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3316</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3317
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3318</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3319
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3320<!-- _______________________________________________________________________ -->
3321<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3322Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3323
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3324<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3326<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3327<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3328 &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]3329</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3330
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3331<h5>Overview:</h5>
3332<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3333
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3334<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3335<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3336 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3337 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3338
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3339<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3340<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3341
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3342<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3343<pre>
3344 &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]3345</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3346
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3347</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3348
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3349<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3350<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3351</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3352
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3353<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3354
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3355<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3356<pre>
3357 &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]3358</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3359
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3360<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3361<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3362 division of its two arguments.</p>
3363
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3364<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3365<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3366 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3367 values. Both arguments must have identical types.</p>
3368
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3369<h5>Semantics:</h5>
3370<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3371 This instruction always performs an unsigned division to get the
3372 remainder.</p>
3373
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3374<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3375 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3376
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3377<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3378
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3379<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3380<pre>
3381 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3382</pre>
3383
3384</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3386<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3387<div class="doc_subsubsection">
3388 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3389</div>
3390
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3391<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3392
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3393<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3394<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3395 &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]3396</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3397
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3398<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3399<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3400 division of its two operands. This instruction can also take
3401 <a href="#t_vector">vector</a> versions of the values in which case the
3402 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3403
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3404<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3405<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3406 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3407 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3408
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3409<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3410<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3411 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3412 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3413 a value. For more information about the difference,
3414 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3415 Math Forum</a>. For a table of how this is implemented in various languages,
3416 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3417 Wikipedia: modulo operation</a>.</p>
3418
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3419<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3420 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3421
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3422<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3423 Overflow also leads to undefined behavior; this is a rare case, but can
3424 occur, for example, by taking the remainder of a 32-bit division of
3425 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3426 lets srem be implemented using instructions that return both the result of
3427 the division and the remainder.)</p>
3428
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3429<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3430<pre>
3431 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3432</pre>
3433
3434</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3435
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3436<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3437<div class="doc_subsubsection">
3438 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3439
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3440<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3441
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3442<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3443<pre>
3444 &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]3445</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3446
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3447<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3448<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3449 its two operands.</p>
3450
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3451<h5>Arguments:</h5>
3452<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3453 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3454 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3455
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3456<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3457<p>This instruction returns the <i>remainder</i> of a division. The remainder
3458 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3459
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3460<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3461<pre>
3462 &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]3463</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3464
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3465</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3466
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3467<!-- ======================================================================= -->
3468<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3469Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3470
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3471<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3472
3473<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3474 program. They are generally very efficient instructions and can commonly be
3475 strength reduced from other instructions. They require two operands of the
3476 same type, execute an operation on them, and produce a single value. The
3477 resulting value is the same type as its operands.</p>
3478
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3479</div>
3480
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3481<!-- _______________________________________________________________________ -->
3482<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3483Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3484
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3485<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3487<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3488<pre>
3489 &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]3490</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3491
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3492<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3493<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3494 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3495
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3496<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3497<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3498 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3499 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3500
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3501<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3502<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3503 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3504 is (statically or dynamically) negative or equal to or larger than the number
3505 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3506 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3507 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3508
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3509<h5>Example:</h5>
3510<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3511 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3512 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3513 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3514 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3515 &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]3516</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3517
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3518</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3519
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3520<!-- _______________________________________________________________________ -->
3521<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3522Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3523
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3524<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3525
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3526<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3527<pre>
3528 &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]3529</pre>
3530
3531<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3533 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3534
3535<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3536<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3537 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3538 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3539
3540<h5>Semantics:</h5>
3541<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3542 significant bits of the result will be filled with zero bits after the shift.
3543 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3544 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3545 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3546 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3547
3548<h5>Example:</h5>
3549<pre>
3550 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3551 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3552 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3553 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3554 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3555 &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]3556</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3557
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3558</div>
3559
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3560<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3561<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3562Instruction</a> </div>
3563<div class="doc_text">
3564
3565<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3566<pre>
3567 &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]3568</pre>
3569
3570<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3571<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3572 operand shifted to the right a specified number of bits with sign
3573 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3574
3575<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3576<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3577 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3578 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3579
3580<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3581<p>This instruction always performs an arithmetic shift right operation, The
3582 most significant bits of the result will be filled with the sign bit
3583 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3584 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3585 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3586 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3587
3588<h5>Example:</h5>
3589<pre>
3590 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3591 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3592 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3593 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3594 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3595 &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]3596</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3597
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3598</div>
3599
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3600<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3601<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3602Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3603
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3604<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3605
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3606<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3607<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3608 &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]3609</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3610
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3611<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3612<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3613 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3614
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3615<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3616<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3617 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3618 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3619
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3620<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3621<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3622
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3623<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3624 <tbody>
3625 <tr>
3626 <td>In0</td>
3627 <td>In1</td>
3628 <td>Out</td>
3629 </tr>
3630 <tr>
3631 <td>0</td>
3632 <td>0</td>
3633 <td>0</td>
3634 </tr>
3635 <tr>
3636 <td>0</td>
3637 <td>1</td>
3638 <td>0</td>
3639 </tr>
3640 <tr>
3641 <td>1</td>
3642 <td>0</td>
3643 <td>0</td>
3644 </tr>
3645 <tr>
3646 <td>1</td>
3647 <td>1</td>
3648 <td>1</td>
3649 </tr>
3650 </tbody>
3651</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3652
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3653<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3654<pre>
3655 &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]3656 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3657 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3658</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3659</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3660<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3661<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3662
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3663<div class="doc_text">
3664
3665<h5>Syntax:</h5>
3666<pre>
3667 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3668</pre>
3669
3670<h5>Overview:</h5>
3671<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3672 two operands.</p>
3673
3674<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3675<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3676 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3677 values. Both arguments must have identical types.</p>
3678
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3679<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3680<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3681
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3682<table border="1" cellspacing="0" cellpadding="4">
3683 <tbody>
3684 <tr>
3685 <td>In0</td>
3686 <td>In1</td>
3687 <td>Out</td>
3688 </tr>
3689 <tr>
3690 <td>0</td>
3691 <td>0</td>
3692 <td>0</td>
3693 </tr>
3694 <tr>
3695 <td>0</td>
3696 <td>1</td>
3697 <td>1</td>
3698 </tr>
3699 <tr>
3700 <td>1</td>
3701 <td>0</td>
3702 <td>1</td>
3703 </tr>
3704 <tr>
3705 <td>1</td>
3706 <td>1</td>
3707 <td>1</td>
3708 </tr>
3709 </tbody>
3710</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3711
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3712<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3713<pre>
3714 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3715 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3716 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3717</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3718
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3719</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3721<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3722<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3723Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3724
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3725<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3727<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3728<pre>
3729 &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]3730</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3732<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3733<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3734 its two operands. The <tt>xor</tt> is used to implement the "one's
3735 complement" operation, which is the "~" operator in C.</p>
3736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3737<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3738<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3739 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3740 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3741
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3742<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3743<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3744
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3745<table border="1" cellspacing="0" cellpadding="4">
3746 <tbody>
3747 <tr>
3748 <td>In0</td>
3749 <td>In1</td>
3750 <td>Out</td>
3751 </tr>
3752 <tr>
3753 <td>0</td>
3754 <td>0</td>
3755 <td>0</td>
3756 </tr>
3757 <tr>
3758 <td>0</td>
3759 <td>1</td>
3760 <td>1</td>
3761 </tr>
3762 <tr>
3763 <td>1</td>
3764 <td>0</td>
3765 <td>1</td>
3766 </tr>
3767 <tr>
3768 <td>1</td>
3769 <td>1</td>
3770 <td>0</td>
3771 </tr>
3772 </tbody>
3773</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3774
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3775<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3776<pre>
3777 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3778 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3779 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3780 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3781</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3782
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3783</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3784
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3785<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3786<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3787 <a name="vectorops">Vector Operations</a>
3788</div>
3789
3790<div class="doc_text">
3791
3792<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3793 target-independent manner. These instructions cover the element-access and
3794 vector-specific operations needed to process vectors effectively. While LLVM
3795 does directly support these vector operations, many sophisticated algorithms
3796 will want to use target-specific intrinsics to take full advantage of a
3797 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3798
3799</div>
3800
3801<!-- _______________________________________________________________________ -->
3802<div class="doc_subsubsection">
3803 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3804</div>
3805
3806<div class="doc_text">
3807
3808<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3809<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3810 &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]3811</pre>
3812
3813<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3814<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3815 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3816
3817
3818<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3819<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3820 of <a href="#t_vector">vector</a> type. The second operand is an index
3821 indicating the position from which to extract the element. The index may be
3822 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3823
3824<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825<p>The result is a scalar of the same type as the element type of
3826 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3827 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3828 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3829
3830<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3831<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3832 &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]3833</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3834
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3835</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3836
3837<!-- _______________________________________________________________________ -->
3838<div class="doc_subsubsection">
3839 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3840</div>
3841
3842<div class="doc_text">
3843
3844<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3845<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3846 &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]3847</pre>
3848
3849<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3850<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3851 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3852
3853<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3854<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3855 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3856 whose type must equal the element type of the first operand. The third
3857 operand is an index indicating the position at which to insert the value.
3858 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3859
3860<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3861<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3862 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3863 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3864 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3865
3866<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3867<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3868 &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]3869</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3870
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3871</div>
3872
3873<!-- _______________________________________________________________________ -->
3874<div class="doc_subsubsection">
3875 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3876</div>
3877
3878<div class="doc_text">
3879
3880<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3881<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3882 &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]3883</pre>
3884
3885<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3886<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3887 from two input vectors, returning a vector with the same element type as the
3888 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3889
3890<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3891<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3892 with types that match each other. The third argument is a shuffle mask whose
3893 element type is always 'i32'. The result of the instruction is a vector
3894 whose length is the same as the shuffle mask and whose element type is the
3895 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3896
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3897<p>The shuffle mask operand is required to be a constant vector with either
3898 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3899
3900<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3901<p>The elements of the two input vectors are numbered from left to right across
3902 both of the vectors. The shuffle mask operand specifies, for each element of
3903 the result vector, which element of the two input vectors the result element
3904 gets. The element selector may be undef (meaning "don't care") and the
3905 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3906
3907<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3908<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3909 &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]3910 &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]3911 &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]3912 &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]3913 &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]3914 &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]3915 &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]3916 &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]3917</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3918
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3919</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3920
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3921<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3922<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3923 <a name="aggregateops">Aggregate Operations</a>
3924</div>
3925
3926<div class="doc_text">
3927
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]3928<p>LLVM supports several instructions for working with
3929 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3930
3931</div>
3932
3933<!-- _______________________________________________________________________ -->
3934<div class="doc_subsubsection">
3935 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3936</div>
3937
3938<div class="doc_text">
3939
3940<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3941<pre>
3942 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3943</pre>
3944
3945<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]3946<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
3947 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3948
3949<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3950<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]3951 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
3952 <a href="#t_array">array</a> type. The operands are constant indices to
3953 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3954 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3955
3956<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3957<p>The result is the value at the position in the aggregate specified by the
3958 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3959
3960<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3961<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3962 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3963</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3964
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3965</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3966
3967<!-- _______________________________________________________________________ -->
3968<div class="doc_subsubsection">
3969 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3970</div>
3971
3972<div class="doc_text">
3973
3974<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3975<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]3976 &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]3977</pre>
3978
3979<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]3980<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
3981 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3982
3983<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3984<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]3985 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
3986 <a href="#t_array">array</a> type. The second operand is a first-class
3987 value to insert. The following operands are constant indices indicating
3988 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]3989 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3990 value to insert must have the same type as the value identified by the
3991 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3992
3993<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3994<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3995 that of <tt>val</tt> except that the value at the position specified by the
3996 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3997
3998<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3999<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4000 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4001 %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]4002</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4003
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4004</div>
4005
4006
4007<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4008<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4009 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4010</div>
4011
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4012<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4014<p>A key design point of an SSA-based representation is how it represents
4015 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4016 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4017 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4018
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4019</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4021<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4022<div class="doc_subsubsection">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4023 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4024</div>
4025
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4026<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4027
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4028<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4029<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4030 &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]4031</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4032
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4033<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4034<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4035 currently executing function, to be automatically released when this function
4036 returns to its caller. The object is always allocated in the generic address
4037 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4038
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4039<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4040<p>The '<tt>alloca</tt>' instruction
4041 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4042 runtime stack, returning a pointer of the appropriate type to the program.
4043 If "NumElements" is specified, it is the number of elements allocated,
4044 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4045 specified, the value result of the allocation is guaranteed to be aligned to
4046 at least that boundary. If not specified, or if zero, the target can choose
4047 to align the allocation on any convenient boundary compatible with the
4048 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4049
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4050<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4052<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4053<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4054 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4055 memory is automatically released when the function returns. The
4056 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4057 variables that must have an address available. When the function returns
4058 (either with the <tt><a href="#i_ret">ret</a></tt>
4059 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4060 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4061
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4062<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4063<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4064 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4065 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4066 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4067 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4068</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4069
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4070</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4071
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4072<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4073<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4074Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4075
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4076<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4077
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4078<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4079<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4080 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4081 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4082 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4083</pre>
4084
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4085<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4086<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4087
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4088<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4089<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4090 from which to load. The pointer must point to
4091 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4092 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4093 number or order of execution of this <tt>load</tt> with other
4094 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4095 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4096
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4097<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4098 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]4099 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4100 alignment for the target. It is the responsibility of the code emitter to
4101 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4102 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4103 produce less efficient code. An alignment of 1 is always safe.</p>
4104
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4105<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4106 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]4107 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4108 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4109 and code generator that this load is not expected to be reused in the cache.
4110 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]4111 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4112
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4113<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4114<p>The location of memory pointed to is loaded. If the value being loaded is of
4115 scalar type then the number of bytes read does not exceed the minimum number
4116 of bytes needed to hold all bits of the type. For example, loading an
4117 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4118 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4119 is undefined if the value was not originally written using a store of the
4120 same type.</p>
4121
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4122<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4123<pre>
4124 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4125 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4126 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4127</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4128
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4129</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4130
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4131<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4132<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4133Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4134
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]4135<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4136
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4137<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4138<pre>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4139 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4140 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]4141</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4142
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4143<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4144<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4145
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4146<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4148 and an address at which to store it. The type of the
4149 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4150 the <a href="#t_firstclass">first class</a> type of the
4151 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4152 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4153 or order of execution of this <tt>store</tt> with other
4154 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4155 instructions.</p>
4156
4157<p>The optional constant "align" argument specifies the alignment of the
4158 operation (that is, the alignment of the memory address). A value of 0 or an
4159 omitted "align" argument means that the operation has the preferential
4160 alignment for the target. It is the responsibility of the code emitter to
4161 ensure that the alignment information is correct. Overestimating the
4162 alignment results in an undefined behavior. Underestimating the alignment may
4163 produce less efficient code. An alignment of 1 is always safe.</p>
4164
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4165<p>The optional !nontemporal metadata must reference a single metatadata
4166 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]4167 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4168 instruction tells the optimizer and code generator that this load is
4169 not expected to be reused in the cache. The code generator may
4170 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]4171 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4172
4173
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4174<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4175<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4176 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4177 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4178 does not exceed the minimum number of bytes needed to hold all bits of the
4179 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4180 writing a value of a type like <tt>i20</tt> with a size that is not an
4181 integral number of bytes, it is unspecified what happens to the extra bits
4182 that do not belong to the type, but they will typically be overwritten.</p>
4183
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4184<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4185<pre>
4186 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4187 store i32 3, i32* %ptr <i>; yields {void}</i>
4188 %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]4189</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4190
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4191</div>
4192
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4193<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4194<div class="doc_subsubsection">
4195 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4196</div>
4197
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4198<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4199
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4200<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4201<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4202 &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]4203 &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]4204</pre>
4205
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4206<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4207<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4208 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4209 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4210
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4211<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4212<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4213 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4214 elements of the aggregate object are indexed. The interpretation of each
4215 index is dependent on the type being indexed into. The first index always
4216 indexes the pointer value given as the first argument, the second index
4217 indexes a value of the type pointed to (not necessarily the value directly
4218 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4219 indexed into must be a pointer value, subsequent types can be arrays,
4220 vectors, structs and unions. Note that subsequent types being indexed into
4221 can never be pointers, since that would require loading the pointer before
4222 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4223
4224<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]4225 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4226 integer <b>constants</b> are allowed. When indexing into an array, pointer
4227 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]4228 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4229
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4230<p>For example, let's consider a C code fragment and how it gets compiled to
4231 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4232
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4233<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4234<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4235struct RT {
4236 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4237 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4238 char C;
4239};
4240struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4241 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4242 double Y;
4243 struct RT Z;
4244};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4245
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4246int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4247 return &amp;s[1].Z.B[5][13];
4248}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4249</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4250</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4251
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4252<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4253
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4254<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4255<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4256%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4257%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4258
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4259define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4260entry:
4261 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4262 ret i32* %reg
4263}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4264</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4265</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4266
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4267<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4268<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]4269 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4270 }</tt>' type, a structure. The second index indexes into the third element
4271 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4272 i8 }</tt>' type, another structure. The third index indexes into the second
4273 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4274 array. The two dimensions of the array are subscripted into, yielding an
4275 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4276 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4277
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4278<p>Note that it is perfectly legal to index partially through a structure,
4279 returning a pointer to an inner element. Because of this, the LLVM code for
4280 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4281
4282<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4283 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4284 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4285 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4286 %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]4287 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4288 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4289 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4290 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4291</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4292
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4293<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4294 <tt>getelementptr</tt> is undefined if the base pointer is not an
4295 <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]4296 that would be formed by successive addition of the offsets implied by the
4297 indices to the base address with infinitely precise arithmetic are not an
4298 <i>in bounds</i> address of that allocated object.
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4299 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4300 that point into the object, plus the address one byte past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4301
4302<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4303 the base address with silently-wrapping two's complement arithmetic, and
4304 the result value of the <tt>getelementptr</tt> may be outside the object
4305 pointed to by the base pointer. The result value may not necessarily be
4306 used to access memory though, even if it happens to point into allocated
4307 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4308 section for more information.</p>
4309
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4310<p>The getelementptr instruction is often confusing. For some more insight into
4311 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4312
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4313<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4314<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4315 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4316 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4317 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4318 %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]4319 <i>; yields i8*:eptr</i>
4320 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4321 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4322 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4323</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4324
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4325</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4327<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4328<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4329</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4331<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4332
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4333<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4334 which all take a single operand and a type. They perform various bit
4335 conversions on the operand.</p>
4336
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4337</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4338
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4339<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4340<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4341 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4342</div>
4343<div class="doc_text">
4344
4345<h5>Syntax:</h5>
4346<pre>
4347 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4348</pre>
4349
4350<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4351<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4352 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4353
4354<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4356 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4357 size and type of the result, which must be
4358 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4359 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4360 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4361
4362<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4363<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4364 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4365 source size must be larger than the destination size, <tt>trunc</tt> cannot
4366 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4367
4368<h5>Example:</h5>
4369<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4370 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4371 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4372 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4373</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4374
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4375</div>
4376
4377<!-- _______________________________________________________________________ -->
4378<div class="doc_subsubsection">
4379 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4380</div>
4381<div class="doc_text">
4382
4383<h5>Syntax:</h5>
4384<pre>
4385 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4386</pre>
4387
4388<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4389<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4390 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4391
4392
4393<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4394<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]4395 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4396 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]4397 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4398 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4399
4400<h5>Semantics:</h5>
4401<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]4402 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4403
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4404<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]4405
4406<h5>Example:</h5>
4407<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4408 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4409 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4410</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4411
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4412</div>
4413
4414<!-- _______________________________________________________________________ -->
4415<div class="doc_subsubsection">
4416 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4417</div>
4418<div class="doc_text">
4419
4420<h5>Syntax:</h5>
4421<pre>
4422 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4423</pre>
4424
4425<h5>Overview:</h5>
4426<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4427
4428<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4429<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]4430 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4431 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]4432 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4433 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4434
4435<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4436<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4437 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4438 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4439
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4440<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]4441
4442<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4443<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4444 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4445 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4446</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4447
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4448</div>
4449
4450<!-- _______________________________________________________________________ -->
4451<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4452 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4453</div>
4454
4455<div class="doc_text">
4456
4457<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4458<pre>
4459 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4460</pre>
4461
4462<h5>Overview:</h5>
4463<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4464 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4465
4466<h5>Arguments:</h5>
4467<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4468 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4469 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]4470 <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]4471 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4472
4473<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4474<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4475 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4476 <a href="#t_floating">floating point</a> type. If the value cannot fit
4477 within the destination type, <tt>ty2</tt>, then the results are
4478 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4479
4480<h5>Example:</h5>
4481<pre>
4482 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4483 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4484</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4485
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4486</div>
4487
4488<!-- _______________________________________________________________________ -->
4489<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4490 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4491</div>
4492<div class="doc_text">
4493
4494<h5>Syntax:</h5>
4495<pre>
4496 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4497</pre>
4498
4499<h5>Overview:</h5>
4500<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]4501 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4502
4503<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4504<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4505 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4506 a <a href="#t_floating">floating point</a> type to cast it to. The source
4507 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4508
4509<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4510<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4511 <a href="#t_floating">floating point</a> type to a larger
4512 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4513 used to make a <i>no-op cast</i> because it always changes bits. Use
4514 <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]4515
4516<h5>Example:</h5>
4517<pre>
4518 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4519 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4520</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4521
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4522</div>
4523
4524<!-- _______________________________________________________________________ -->
4525<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4526 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4527</div>
4528<div class="doc_text">
4529
4530<h5>Syntax:</h5>
4531<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4532 &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]4533</pre>
4534
4535<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4536<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4537 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4538
4539<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4540<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4541 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4542 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4543 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4544 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4545
4546<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4547<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4548 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4549 towards zero) unsigned integer value. If the value cannot fit
4550 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4551
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4552<h5>Example:</h5>
4553<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4554 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4555 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4556 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4557</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4558
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4559</div>
4560
4561<!-- _______________________________________________________________________ -->
4562<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4563 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4564</div>
4565<div class="doc_text">
4566
4567<h5>Syntax:</h5>
4568<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4569 &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]4570</pre>
4571
4572<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4573<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4574 <a href="#t_floating">floating point</a> <tt>value</tt> to
4575 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4576
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4577<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4578<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4579 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4580 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4581 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4582 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4583
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4584<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4585<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4586 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4587 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4588 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4589
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4590<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4591<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4592 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4593 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4594 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4595</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4596
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4597</div>
4598
4599<!-- _______________________________________________________________________ -->
4600<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4601 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4602</div>
4603<div class="doc_text">
4604
4605<h5>Syntax:</h5>
4606<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4607 &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]4608</pre>
4609
4610<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4611<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4612 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4613
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4614<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4615<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]4616 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4617 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4618 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4619 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4620
4621<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4622<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4623 integer quantity and converts it to the corresponding floating point
4624 value. If the value cannot fit in the floating point value, the results are
4625 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4626
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4627<h5>Example:</h5>
4628<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4629 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4630 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4631</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4632
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4633</div>
4634
4635<!-- _______________________________________________________________________ -->
4636<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4637 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4638</div>
4639<div class="doc_text">
4640
4641<h5>Syntax:</h5>
4642<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4643 &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]4644</pre>
4645
4646<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4647<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4648 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4649
4650<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4651<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]4652 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4653 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4654 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4655 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4656
4657<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4658<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4659 quantity and converts it to the corresponding floating point value. If the
4660 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4661
4662<h5>Example:</h5>
4663<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4664 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4665 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4666</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4667
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4668</div>
4669
4670<!-- _______________________________________________________________________ -->
4671<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4672 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4673</div>
4674<div class="doc_text">
4675
4676<h5>Syntax:</h5>
4677<pre>
4678 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4679</pre>
4680
4681<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4682<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4683 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4684
4685<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4686<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4687 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4688 <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]4689
4690<h5>Semantics:</h5>
4691<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4692 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4693 truncating or zero extending that value to the size of the integer type. If
4694 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4695 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4696 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4697 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4698
4699<h5>Example:</h5>
4700<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4701 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4702 %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]4703</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4704
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4705</div>
4706
4707<!-- _______________________________________________________________________ -->
4708<div class="doc_subsubsection">
4709 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4710</div>
4711<div class="doc_text">
4712
4713<h5>Syntax:</h5>
4714<pre>
4715 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4716</pre>
4717
4718<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4719<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4720 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4721
4722<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4723<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4724 value to cast, and a type to cast it to, which must be a
4725 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4726
4727<h5>Semantics:</h5>
4728<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4729 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4730 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4731 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4732 than the size of a pointer then a zero extension is done. If they are the
4733 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4734
4735<h5>Example:</h5>
4736<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4737 %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]4738 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4739 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4740</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4741
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4742</div>
4743
4744<!-- _______________________________________________________________________ -->
4745<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4746 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4747</div>
4748<div class="doc_text">
4749
4750<h5>Syntax:</h5>
4751<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4752 &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]4753</pre>
4754
4755<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4756<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4757 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4758
4759<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4760<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4761 non-aggregate first class value, and a type to cast it to, which must also be
4762 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4763 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4764 identical. If the source type is a pointer, the destination type must also be
4765 a pointer. This instruction supports bitwise conversion of vectors to
4766 integers and to vectors of other types (as long as they have the same
4767 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4768
4769<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4770<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4771 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4772 this conversion. The conversion is done as if the <tt>value</tt> had been
4773 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4774 be converted to other pointer types with this instruction. To convert
4775 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4776 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4777
4778<h5>Example:</h5>
4779<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4780 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4781 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4782 %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]4783</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4784
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4785</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4786
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4787<!-- ======================================================================= -->
4788<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4789
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4790<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4791
4792<p>The instructions in this category are the "miscellaneous" instructions, which
4793 defy better classification.</p>
4794
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4795</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4796
4797<!-- _______________________________________________________________________ -->
4798<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4799</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4800
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4801<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4802
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4803<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4804<pre>
4805 &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]4806</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4807
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4808<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4809<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4810 boolean values based on comparison of its two integer, integer vector, or
4811 pointer operands.</p>
4812
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4813<h5>Arguments:</h5>
4814<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4815 the condition code indicating the kind of comparison to perform. It is not a
4816 value, just a keyword. The possible condition code are:</p>
4817
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4818<ol>
4819 <li><tt>eq</tt>: equal</li>
4820 <li><tt>ne</tt>: not equal </li>
4821 <li><tt>ugt</tt>: unsigned greater than</li>
4822 <li><tt>uge</tt>: unsigned greater or equal</li>
4823 <li><tt>ult</tt>: unsigned less than</li>
4824 <li><tt>ule</tt>: unsigned less or equal</li>
4825 <li><tt>sgt</tt>: signed greater than</li>
4826 <li><tt>sge</tt>: signed greater or equal</li>
4827 <li><tt>slt</tt>: signed less than</li>
4828 <li><tt>sle</tt>: signed less or equal</li>
4829</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4830
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4831<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4832 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4833 typed. They must also be identical types.</p>
4834
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4835<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4836<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4837 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4838 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]4839 result, as follows:</p>
4840
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4841<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4842 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4843 <tt>false</tt> otherwise. No sign interpretation is necessary or
4844 performed.</li>
4845
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4846 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4847 <tt>false</tt> otherwise. No sign interpretation is necessary or
4848 performed.</li>
4849
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4850 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4851 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4852
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4853 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4854 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4855 to <tt>op2</tt>.</li>
4856
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4857 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4858 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4859
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4860 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4861 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4862
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4863 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4864 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4865
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4866 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4867 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4868 to <tt>op2</tt>.</li>
4869
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4870 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4871 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4872
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4873 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4874 <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]4875</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4876
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4877<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4878 values are compared as if they were integers.</p>
4879
4880<p>If the operands are integer vectors, then they are compared element by
4881 element. The result is an <tt>i1</tt> vector with the same number of elements
4882 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4883
4884<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4885<pre>
4886 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4887 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4888 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4889 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4890 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4891 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4892</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4893
4894<p>Note that the code generator does not yet support vector types with
4895 the <tt>icmp</tt> instruction.</p>
4896
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4897</div>
4898
4899<!-- _______________________________________________________________________ -->
4900<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4901</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4902
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4903<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4904
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4905<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4906<pre>
4907 &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]4908</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4909
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4910<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4911<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4912 values based on comparison of its operands.</p>
4913
4914<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]4915(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4916
4917<p>If the operands are floating point vectors, then the result type is a vector
4918 of boolean with the same number of elements as the operands being
4919 compared.</p>
4920
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4921<h5>Arguments:</h5>
4922<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4923 the condition code indicating the kind of comparison to perform. It is not a
4924 value, just a keyword. The possible condition code are:</p>
4925
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4926<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4927 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4928 <li><tt>oeq</tt>: ordered and equal</li>
4929 <li><tt>ogt</tt>: ordered and greater than </li>
4930 <li><tt>oge</tt>: ordered and greater than or equal</li>
4931 <li><tt>olt</tt>: ordered and less than </li>
4932 <li><tt>ole</tt>: ordered and less than or equal</li>
4933 <li><tt>one</tt>: ordered and not equal</li>
4934 <li><tt>ord</tt>: ordered (no nans)</li>
4935 <li><tt>ueq</tt>: unordered or equal</li>
4936 <li><tt>ugt</tt>: unordered or greater than </li>
4937 <li><tt>uge</tt>: unordered or greater than or equal</li>
4938 <li><tt>ult</tt>: unordered or less than </li>
4939 <li><tt>ule</tt>: unordered or less than or equal</li>
4940 <li><tt>une</tt>: unordered or not equal</li>
4941 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4942 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4943</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4944
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4945<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4946 <i>unordered</i> means that either operand may be a QNAN.</p>
4947
4948<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4949 a <a href="#t_floating">floating point</a> type or
4950 a <a href="#t_vector">vector</a> of floating point type. They must have
4951 identical types.</p>
4952
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4953<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4954<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4955 according to the condition code given as <tt>cond</tt>. If the operands are
4956 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4957 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4958 follows:</p>
4959
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4960<ol>
4961 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4962
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4963 <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]4964 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4965
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4966 <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^]4967 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4968
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4969 <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]4970 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4971
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4972 <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]4973 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4974
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4975 <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]4976 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4977
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4978 <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]4979 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4980
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4981 <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]4982
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4983 <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]4984 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4985
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4986 <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]4987 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4988
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4989 <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]4990 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4991
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4992 <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]4993 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4994
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4995 <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]4996 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4997
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4998 <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]4999 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5000
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5001 <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]5002
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5003 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5004</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5005
5006<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5007<pre>
5008 &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]5009 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5010 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5011 &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]5012</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5013
5014<p>Note that the code generator does not yet support vector types with
5015 the <tt>fcmp</tt> instruction.</p>
5016
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5017</div>
5018
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5019<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]5020<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5021 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5022</div>
5023
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5024<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5025
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5026<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5027<pre>
5028 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5029</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5030
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5031<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5032<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5033 SSA graph representing the function.</p>
5034
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5035<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5036<p>The type of the incoming values is specified with the first type field. After
5037 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5038 one pair for each predecessor basic block of the current block. Only values
5039 of <a href="#t_firstclass">first class</a> type may be used as the value
5040 arguments to the PHI node. Only labels may be used as the label
5041 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5042
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5043<p>There must be no non-phi instructions between the start of a basic block and
5044 the PHI instructions: i.e. PHI instructions must be first in a basic
5045 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5046
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5047<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5048 occur on the edge from the corresponding predecessor block to the current
5049 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5050 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5051
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5052<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5053<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5054 specified by the pair corresponding to the predecessor basic block that
5055 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5056
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5057<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5058<pre>
5059Loop: ; Infinite loop that counts from 0 on up...
5060 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5061 %nextindvar = add i32 %indvar, 1
5062 br label %Loop
5063</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5064
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5065</div>
5066
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5067<!-- _______________________________________________________________________ -->
5068<div class="doc_subsubsection">
5069 <a name="i_select">'<tt>select</tt>' Instruction</a>
5070</div>
5071
5072<div class="doc_text">
5073
5074<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5075<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5076 &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>
5077
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5078 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5079</pre>
5080
5081<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5082<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5083 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5084
5085
5086<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5087<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5088 values indicating the condition, and two values of the
5089 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5090 vectors and the condition is a scalar, then entire vectors are selected, not
5091 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5092
5093<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5094<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5095 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5096
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5097<p>If the condition is a vector of i1, then the value arguments must be vectors
5098 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5099
5100<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5101<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5102 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5103</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5104
5105<p>Note that the code generator does not yet support conditions
5106 with vector type.</p>
5107
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5108</div>
5109
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5110<!-- _______________________________________________________________________ -->
5111<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5112 <a name="i_call">'<tt>call</tt>' Instruction</a>
5113</div>
5114
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5115<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5116
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5117<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5118<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5119 &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]5120</pre>
5121
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5122<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5123<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5124
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5125<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5126<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5127
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5128<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5129 <li>The optional "tail" marker indicates that the callee function does not
5130 access any allocas or varargs in the caller. Note that calls may be
5131 marked "tail" even if they do not occur before
5132 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5133 present, the function call is eligible for tail call optimization,
5134 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
5135 optimized into a jump</a>. As of this writing, the extra requirements for
5136 a call to actually be optimized are:
5137 <ul>
5138 <li>Caller and callee both have the calling
5139 convention <tt>fastcc</tt>.</li>
5140 <li>The call is in tail position (ret immediately follows call and ret
5141 uses value of call or is void).</li>
5142 <li>Option <tt>-tailcallopt</tt> is enabled,
5143 or <code>llvm::PerformTailCallOpt</code> is <code>true</code>.</li>
5144 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5145 constraints are met.</a></li>
5146 </ul>
5147 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5148
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5149 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5150 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5151 defaults to using C calling conventions. The calling convention of the
5152 call must match the calling convention of the target function, or else the
5153 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5154
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5155 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5156 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5157 '<tt>inreg</tt>' attributes are valid here.</li>
5158
5159 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5160 type of the return value. Functions that return no value are marked
5161 <tt><a href="#t_void">void</a></tt>.</li>
5162
5163 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5164 being invoked. The argument types must match the types implied by this
5165 signature. This type can be omitted if the function is not varargs and if
5166 the function type does not return a pointer to a function.</li>
5167
5168 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5169 be invoked. In most cases, this is a direct function invocation, but
5170 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5171 to function value.</li>
5172
5173 <li>'<tt>function args</tt>': argument list whose types match the function
5174 signature argument types. All arguments must be of
5175 <a href="#t_firstclass">first class</a> type. If the function signature
5176 indicates the function accepts a variable number of arguments, the extra
5177 arguments can be specified.</li>
5178
5179 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5180 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5181 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5182</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5183
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5184<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5185<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5186 a specified function, with its incoming arguments bound to the specified
5187 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5188 function, control flow continues with the instruction after the function
5189 call, and the return value of the function is bound to the result
5190 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5191
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5192<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5193<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5194 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5195 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5196 %X = tail call i32 @foo() <i>; yields i32</i>
5197 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5198 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5199
5200 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5201 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5202 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5203 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5204 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5205 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5206</pre>
5207
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5208<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5209standard C99 library as being the C99 library functions, and may perform
5210optimizations or generate code for them under that assumption. This is
5211something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]5212freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5213
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5214</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5215
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5216<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5217<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5218 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5219</div>
5220
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5221<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5222
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5223<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5224<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5225 &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]5226</pre>
5227
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5228<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5229<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5230 the "variable argument" area of a function call. It is used to implement the
5231 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5232
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5233<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5234<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5235 argument. It returns a value of the specified argument type and increments
5236 the <tt>va_list</tt> to point to the next argument. The actual type
5237 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5238
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5239<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5240<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5241 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5242 to the next argument. For more information, see the variable argument
5243 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5244
5245<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]5246 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5247 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5248
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5249<p><tt>va_arg</tt> is an LLVM instruction instead of
5250 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5251 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5252
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5253<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5254<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5255
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256<p>Note that the code generator does not yet fully support va_arg on many
5257 targets. Also, it does not currently support va_arg with aggregate types on
5258 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5259
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5260</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5261
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5262<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5263<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5264<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5266<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5267
5268<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5269 well known names and semantics and are required to follow certain
5270 restrictions. Overall, these intrinsics represent an extension mechanism for
5271 the LLVM language that does not require changing all of the transformations
5272 in LLVM when adding to the language (or the bitcode reader/writer, the
5273 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5274
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5275<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5276 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5277 begin with this prefix. Intrinsic functions must always be external
5278 functions: you cannot define the body of intrinsic functions. Intrinsic
5279 functions may only be used in call or invoke instructions: it is illegal to
5280 take the address of an intrinsic function. Additionally, because intrinsic
5281 functions are part of the LLVM language, it is required if any are added that
5282 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5283
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5284<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5285 family of functions that perform the same operation but on different data
5286 types. Because LLVM can represent over 8 million different integer types,
5287 overloading is used commonly to allow an intrinsic function to operate on any
5288 integer type. One or more of the argument types or the result type can be
5289 overloaded to accept any integer type. Argument types may also be defined as
5290 exactly matching a previous argument's type or the result type. This allows
5291 an intrinsic function which accepts multiple arguments, but needs all of them
5292 to be of the same type, to only be overloaded with respect to a single
5293 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5294
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5295<p>Overloaded intrinsics will have the names of its overloaded argument types
5296 encoded into its function name, each preceded by a period. Only those types
5297 which are overloaded result in a name suffix. Arguments whose type is matched
5298 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5299 can take an integer of any width and returns an integer of exactly the same
5300 integer width. This leads to a family of functions such as
5301 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5302 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5303 suffix is required. Because the argument's type is matched against the return
5304 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5305
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5306<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5307 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5308
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5309</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5310
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5311<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5312<div class="doc_subsection">
5313 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5314</div>
5315
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5316<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5317
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5318<p>Variable argument support is defined in LLVM with
5319 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5320 intrinsic functions. These functions are related to the similarly named
5321 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5322
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5323<p>All of these functions operate on arguments that use a target-specific value
5324 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5325 not define what this type is, so all transformations should be prepared to
5326 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5327
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5328<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]5329 instruction and the variable argument handling intrinsic functions are
5330 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5331
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5332<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5333<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5334define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5335 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5336 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5337 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5338 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5339
5340 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5341 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5342
5343 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5344 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5345 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5346 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5347 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5348
5349 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5350 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5351 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5352}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5353
5354declare void @llvm.va_start(i8*)
5355declare void @llvm.va_copy(i8*, i8*)
5356declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5357</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5358</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5359
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5360</div>
5361
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5362<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5363<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5364 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5365</div>
5366
5367
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5368<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5369
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5370<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5371<pre>
5372 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5373</pre>
5374
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5375<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5376<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5377 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]5378
5379<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5380<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]5381
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5382<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5383<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]5384 macro available in C. In a target-dependent way, it initializes
5385 the <tt>va_list</tt> element to which the argument points, so that the next
5386 call to <tt>va_arg</tt> will produce the first variable argument passed to
5387 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5388 need to know the last argument of the function as the compiler can figure
5389 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5390
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5391</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5392
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5393<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5394<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5395 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5396</div>
5397
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5398<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5399
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5400<h5>Syntax:</h5>
5401<pre>
5402 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5403</pre>
5404
5405<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5406<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5407 which has been initialized previously
5408 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5409 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5410
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5411<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5412<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]5413
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5414<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5415<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]5416 macro available in C. In a target-dependent way, it destroys
5417 the <tt>va_list</tt> element to which the argument points. Calls
5418 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5419 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5420 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5421
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5422</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5423
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5424<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5425<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5426 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5427</div>
5428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5429<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5430
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5431<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5432<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5433 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5434</pre>
5435
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5436<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5437<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5438 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5439
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5440<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5441<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]5442 The second argument is a pointer to a <tt>va_list</tt> element to copy
5443 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5444
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5445<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5446<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]5447 macro available in C. In a target-dependent way, it copies the
5448 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5449 element. This intrinsic is necessary because
5450 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5451 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5453</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5454
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5455<!-- ======================================================================= -->
5456<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5457 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5458</div>
5459
5460<div class="doc_text">
5461
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5462<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5463Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5464intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5465roots on the stack</a>, as well as garbage collector implementations that
5466require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5467barriers. Front-ends for type-safe garbage collected languages should generate
5468these intrinsics to make use of the LLVM garbage collectors. For more details,
5469see <a href="GarbageCollection.html">Accurate Garbage Collection with
5470LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5471
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5472<p>The garbage collection intrinsics only operate on objects in the generic
5473 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5474
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5475</div>
5476
5477<!-- _______________________________________________________________________ -->
5478<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5479 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5480</div>
5481
5482<div class="doc_text">
5483
5484<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5485<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5486 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5487</pre>
5488
5489<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5490<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]5491 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5492
5493<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5494<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5495 root pointer. The second pointer (which must be either a constant or a
5496 global value address) contains the meta-data to be associated with the
5497 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5498
5499<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5500<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]5501 location. At compile-time, the code generator generates information to allow
5502 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5503 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5504 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5505
5506</div>
5507
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5508<!-- _______________________________________________________________________ -->
5509<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5510 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5511</div>
5512
5513<div class="doc_text">
5514
5515<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5516<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5517 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5518</pre>
5519
5520<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5521<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5522 locations, allowing garbage collector implementations that require read
5523 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5524
5525<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5526<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]5527 allocated from the garbage collector. The first object is a pointer to the
5528 start of the referenced object, if needed by the language runtime (otherwise
5529 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5530
5531<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5532<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5533 instruction, but may be replaced with substantially more complex code by the
5534 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5535 may only be used in a function which <a href="#gc">specifies a GC
5536 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5537
5538</div>
5539
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5540<!-- _______________________________________________________________________ -->
5541<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5542 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5543</div>
5544
5545<div class="doc_text">
5546
5547<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5548<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5549 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5550</pre>
5551
5552<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5553<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5554 locations, allowing garbage collector implementations that require write
5555 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5556
5557<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5558<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]5559 object to store it to, and the third is the address of the field of Obj to
5560 store to. If the runtime does not require a pointer to the object, Obj may
5561 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5562
5563<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5564<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5565 instruction, but may be replaced with substantially more complex code by the
5566 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5567 may only be used in a function which <a href="#gc">specifies a GC
5568 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5569
5570</div>
5571
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5572<!-- ======================================================================= -->
5573<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5574 <a name="int_codegen">Code Generator Intrinsics</a>
5575</div>
5576
5577<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5578
5579<p>These intrinsics are provided by LLVM to expose special features that may
5580 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5581
5582</div>
5583
5584<!-- _______________________________________________________________________ -->
5585<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5586 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5587</div>
5588
5589<div class="doc_text">
5590
5591<h5>Syntax:</h5>
5592<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5593 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5594</pre>
5595
5596<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5597<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5598 target-specific value indicating the return address of the current function
5599 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5600
5601<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5602<p>The argument to this intrinsic indicates which function to return the address
5603 for. Zero indicates the calling function, one indicates its caller, etc.
5604 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5605
5606<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5607<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5608 indicating the return address of the specified call frame, or zero if it
5609 cannot be identified. The value returned by this intrinsic is likely to be
5610 incorrect or 0 for arguments other than zero, so it should only be used for
5611 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5612
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613<p>Note that calling this intrinsic does not prevent function inlining or other
5614 aggressive transformations, so the value returned may not be that of the
5615 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5616
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5617</div>
5618
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5619<!-- _______________________________________________________________________ -->
5620<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5621 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5622</div>
5623
5624<div class="doc_text">
5625
5626<h5>Syntax:</h5>
5627<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5628 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5629</pre>
5630
5631<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5632<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5633 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5634
5635<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5636<p>The argument to this intrinsic indicates which function to return the frame
5637 pointer for. Zero indicates the calling function, one indicates its caller,
5638 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5639
5640<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5641<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5642 indicating the frame address of the specified call frame, or zero if it
5643 cannot be identified. The value returned by this intrinsic is likely to be
5644 incorrect or 0 for arguments other than zero, so it should only be used for
5645 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5646
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5647<p>Note that calling this intrinsic does not prevent function inlining or other
5648 aggressive transformations, so the value returned may not be that of the
5649 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5650
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5651</div>
5652
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5653<!-- _______________________________________________________________________ -->
5654<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5655 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5656</div>
5657
5658<div class="doc_text">
5659
5660<h5>Syntax:</h5>
5661<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5662 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5663</pre>
5664
5665<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5666<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5667 of the function stack, for use
5668 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5669 useful for implementing language features like scoped automatic variable
5670 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5671
5672<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5673<p>This intrinsic returns a opaque pointer value that can be passed
5674 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5675 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5676 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5677 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5678 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5679 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5680
5681</div>
5682
5683<!-- _______________________________________________________________________ -->
5684<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5685 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5686</div>
5687
5688<div class="doc_text">
5689
5690<h5>Syntax:</h5>
5691<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5692 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5693</pre>
5694
5695<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5696<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5697 the function stack to the state it was in when the
5698 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5699 executed. This is useful for implementing language features like scoped
5700 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5701
5702<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5703<p>See the description
5704 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5705
5706</div>
5707
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5708<!-- _______________________________________________________________________ -->
5709<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5710 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5711</div>
5712
5713<div class="doc_text">
5714
5715<h5>Syntax:</h5>
5716<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5717 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]5718</pre>
5719
5720<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5721<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5722 insert a prefetch instruction if supported; otherwise, it is a noop.
5723 Prefetches have no effect on the behavior of the program but can change its
5724 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5725
5726<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5727<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5728 specifier determining if the fetch should be for a read (0) or write (1),
5729 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5730 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5731 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5732
5733<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5734<p>This intrinsic does not modify the behavior of the program. In particular,
5735 prefetches cannot trap and do not produce a value. On targets that support
5736 this intrinsic, the prefetch can provide hints to the processor cache for
5737 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5738
5739</div>
5740
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5741<!-- _______________________________________________________________________ -->
5742<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5743 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5744</div>
5745
5746<div class="doc_text">
5747
5748<h5>Syntax:</h5>
5749<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5750 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5751</pre>
5752
5753<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5754<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5755 Counter (PC) in a region of code to simulators and other tools. The method
5756 is target specific, but it is expected that the marker will use exported
5757 symbols to transmit the PC of the marker. The marker makes no guarantees
5758 that it will remain with any specific instruction after optimizations. It is
5759 possible that the presence of a marker will inhibit optimizations. The
5760 intended use is to be inserted after optimizations to allow correlations of
5761 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5762
5763<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5764<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5765
5766<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5767<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]5768 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5769
5770</div>
5771
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5772<!-- _______________________________________________________________________ -->
5773<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5774 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5775</div>
5776
5777<div class="doc_text">
5778
5779<h5>Syntax:</h5>
5780<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5781 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5782</pre>
5783
5784<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5785<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5786 counter register (or similar low latency, high accuracy clocks) on those
5787 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5788 should map to RPCC. As the backing counters overflow quickly (on the order
5789 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5790
5791<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5792<p>When directly supported, reading the cycle counter should not modify any
5793 memory. Implementations are allowed to either return a application specific
5794 value or a system wide value. On backends without support, this is lowered
5795 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5796
5797</div>
5798
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5799<!-- ======================================================================= -->
5800<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5801 <a name="int_libc">Standard C Library Intrinsics</a>
5802</div>
5803
5804<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5805
5806<p>LLVM provides intrinsics for a few important standard C library functions.
5807 These intrinsics allow source-language front-ends to pass information about
5808 the alignment of the pointer arguments to the code generator, providing
5809 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5810
5811</div>
5812
5813<!-- _______________________________________________________________________ -->
5814<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5815 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5816</div>
5817
5818<div class="doc_text">
5819
5820<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5821<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5822 integer bit width. Not all targets support all bit widths however.</p>
5823
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5824<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5825 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5826 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5827 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5828 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5829 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5830 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5831 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5832 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5833</pre>
5834
5835<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5836<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5837 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5839<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5840 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5841
5842<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5843<p>The first argument is a pointer to the destination, the second is a pointer
5844 to the source. The third argument is an integer argument specifying the
5845 number of bytes to copy, and the fourth argument is the alignment of the
5846 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5847
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]5848<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]5849 then the caller guarantees that both the source and destination pointers are
5850 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5851
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5852<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5853<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5854 source location to the destination location, which are not allowed to
5855 overlap. It copies "len" bytes of memory over. If the argument is known to
5856 be aligned to some boundary, this can be specified as the fourth argument,
5857 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5858
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5859</div>
5860
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5861<!-- _______________________________________________________________________ -->
5862<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5863 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5864</div>
5865
5866<div class="doc_text">
5867
5868<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5869<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5870 width. Not all targets support all bit widths however.</p>
5871
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5872<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5873 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5874 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5875 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5876 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5877 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5878 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5879 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5880 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5881</pre>
5882
5883<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5884<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5885 source location to the destination location. It is similar to the
5886 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5887 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5888
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5889<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5890 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5891
5892<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5893<p>The first argument is a pointer to the destination, the second is a pointer
5894 to the source. The third argument is an integer argument specifying the
5895 number of bytes to copy, and the fourth argument is the alignment of the
5896 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5897
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]5898<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]5899 then the caller guarantees that the source and destination pointers are
5900 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5901
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5902<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5903<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5904 source location to the destination location, which may overlap. It copies
5905 "len" bytes of memory over. If the argument is known to be aligned to some
5906 boundary, this can be specified as the fourth argument, otherwise it should
5907 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5908
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5909</div>
5910
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5911<!-- _______________________________________________________________________ -->
5912<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5913 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5914</div>
5915
5916<div class="doc_text">
5917
5918<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5919<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5920 width. Not all targets support all bit widths however.</p>
5921
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5922<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5923 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5924 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5925 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5926 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5927 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5928 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5929 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5930 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5931</pre>
5932
5933<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5934<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5935 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5936
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5937<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5938 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5939
5940<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5941<p>The first argument is a pointer to the destination to fill, the second is the
5942 byte value to fill it with, the third argument is an integer argument
5943 specifying the number of bytes to fill, and the fourth argument is the known
5944 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5945
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]5946<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]5947 then the caller guarantees that the destination pointer is aligned to that
5948 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5949
5950<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5951<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5952 at the destination location. If the argument is known to be aligned to some
5953 boundary, this can be specified as the fourth argument, otherwise it should
5954 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5955
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5956</div>
5957
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5958<!-- _______________________________________________________________________ -->
5959<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5960 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5961</div>
5962
5963<div class="doc_text">
5964
5965<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5966<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5967 floating point or vector of floating point type. Not all targets support all
5968 types however.</p>
5969
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5970<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5971 declare float @llvm.sqrt.f32(float %Val)
5972 declare double @llvm.sqrt.f64(double %Val)
5973 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5974 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5975 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5976</pre>
5977
5978<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5979<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5980 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5981 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5982 behavior for negative numbers other than -0.0 (which allows for better
5983 optimization, because there is no need to worry about errno being
5984 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]5985
5986<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5987<p>The argument and return value are floating point numbers of the same
5988 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5989
5990<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5991<p>This function returns the sqrt of the specified operand if it is a
5992 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5993
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5994</div>
5995
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5996<!-- _______________________________________________________________________ -->
5997<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5998 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5999</div>
6000
6001<div class="doc_text">
6002
6003<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6004<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6005 floating point or vector of floating point type. Not all targets support all
6006 types however.</p>
6007
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6008<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6009 declare float @llvm.powi.f32(float %Val, i32 %power)
6010 declare double @llvm.powi.f64(double %Val, i32 %power)
6011 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6012 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6013 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6014</pre>
6015
6016<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6017<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6018 specified (positive or negative) power. The order of evaluation of
6019 multiplications is not defined. When a vector of floating point type is
6020 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6021
6022<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6023<p>The second argument is an integer power, and the first is a value to raise to
6024 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6025
6026<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6027<p>This function returns the first value raised to the second power with an
6028 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6029
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6030</div>
6031
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6032<!-- _______________________________________________________________________ -->
6033<div class="doc_subsubsection">
6034 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
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.sin</tt> on any
6041 floating point or vector of floating point type. Not all targets support all
6042 types however.</p>
6043
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6044<pre>
6045 declare float @llvm.sin.f32(float %Val)
6046 declare double @llvm.sin.f64(double %Val)
6047 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6048 declare fp128 @llvm.sin.f128(fp128 %Val)
6049 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6050</pre>
6051
6052<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6053<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6054
6055<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6056<p>The argument and return value are floating point numbers of the same
6057 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6058
6059<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6060<p>This function returns the sine of the specified operand, returning the same
6061 values as the libm <tt>sin</tt> functions would, and handles error conditions
6062 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6063
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6064</div>
6065
6066<!-- _______________________________________________________________________ -->
6067<div class="doc_subsubsection">
6068 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6069</div>
6070
6071<div class="doc_text">
6072
6073<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6074<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6075 floating point or vector of floating point type. Not all targets support all
6076 types however.</p>
6077
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6078<pre>
6079 declare float @llvm.cos.f32(float %Val)
6080 declare double @llvm.cos.f64(double %Val)
6081 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6082 declare fp128 @llvm.cos.f128(fp128 %Val)
6083 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6084</pre>
6085
6086<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6087<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6088
6089<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6090<p>The argument and return value are floating point numbers of the same
6091 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6092
6093<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6094<p>This function returns the cosine of the specified operand, returning the same
6095 values as the libm <tt>cos</tt> functions would, and handles error conditions
6096 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6097
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6098</div>
6099
6100<!-- _______________________________________________________________________ -->
6101<div class="doc_subsubsection">
6102 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6103</div>
6104
6105<div class="doc_text">
6106
6107<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6108<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6109 floating point or vector of floating point type. Not all targets support all
6110 types however.</p>
6111
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6112<pre>
6113 declare float @llvm.pow.f32(float %Val, float %Power)
6114 declare double @llvm.pow.f64(double %Val, double %Power)
6115 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6116 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6117 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6118</pre>
6119
6120<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6121<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6122 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6123
6124<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6125<p>The second argument is a floating point power, and the first is a value to
6126 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6127
6128<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6129<p>This function returns the first value raised to the second power, returning
6130 the same values as the libm <tt>pow</tt> functions would, and handles error
6131 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6132
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6133</div>
6134
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6135<!-- ======================================================================= -->
6136<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6137 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6138</div>
6139
6140<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6141
6142<p>LLVM provides intrinsics for a few important bit manipulation operations.
6143 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6144
6145</div>
6146
6147<!-- _______________________________________________________________________ -->
6148<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6149 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6150</div>
6151
6152<div class="doc_text">
6153
6154<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6155<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6156 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6157
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6158<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6159 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6160 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6161 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6162</pre>
6163
6164<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6165<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6166 values with an even number of bytes (positive multiple of 16 bits). These
6167 are useful for performing operations on data that is not in the target's
6168 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6169
6170<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6171<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6172 and low byte of the input i16 swapped. Similarly,
6173 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6174 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6175 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6176 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6177 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6178 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6179
6180</div>
6181
6182<!-- _______________________________________________________________________ -->
6183<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6184 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6185</div>
6186
6187<div class="doc_text">
6188
6189<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6190<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]6191 width. Not all targets support all bit widths however.</p>
6192
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6193<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6194 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6195 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6196 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6197 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6198 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6199</pre>
6200
6201<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6202<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6203 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6204
6205<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6206<p>The only argument is the value to be counted. The argument may be of any
6207 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6208
6209<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6210<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]6211
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6212</div>
6213
6214<!-- _______________________________________________________________________ -->
6215<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6216 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6217</div>
6218
6219<div class="doc_text">
6220
6221<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6222<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6223 integer bit width. Not all targets support all bit widths however.</p>
6224
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6225<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6226 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6227 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6228 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6229 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6230 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6231</pre>
6232
6233<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6234<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6235 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6236
6237<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6238<p>The only argument is the value to be counted. The argument may be of any
6239 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6240
6241<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6242<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6243 zeros in a variable. If the src == 0 then the result is the size in bits of
6244 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6245
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6246</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6247
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6248<!-- _______________________________________________________________________ -->
6249<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6250 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6251</div>
6252
6253<div class="doc_text">
6254
6255<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6256<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6257 integer bit width. Not all targets support all bit widths however.</p>
6258
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6259<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6260 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6261 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6262 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6263 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6264 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6265</pre>
6266
6267<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6268<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6269 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6270
6271<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6272<p>The only argument is the value to be counted. The argument may be of any
6273 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6274
6275<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6276<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6277 zeros in a variable. If the src == 0 then the result is the size in bits of
6278 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6279
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6280</div>
6281
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6282<!-- ======================================================================= -->
6283<div class="doc_subsection">
6284 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6285</div>
6286
6287<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6288
6289<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6290
6291</div>
6292
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6293<!-- _______________________________________________________________________ -->
6294<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6295 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6296</div>
6297
6298<div class="doc_text">
6299
6300<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6301<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]6302 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6303
6304<pre>
6305 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6306 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6307 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6308</pre>
6309
6310<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6311<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6312 a signed addition of the two arguments, and indicate whether an overflow
6313 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6314
6315<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6316<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]6317 be of integer types of any bit width, but they must have the same bit
6318 width. The second element of the result structure must be of
6319 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6320 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6321
6322<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6323<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6324 a signed addition of the two variables. They return a structure &mdash; the
6325 first element of which is the signed summation, and the second element of
6326 which is a bit specifying if the signed summation resulted in an
6327 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6328
6329<h5>Examples:</h5>
6330<pre>
6331 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6332 %sum = extractvalue {i32, i1} %res, 0
6333 %obit = extractvalue {i32, i1} %res, 1
6334 br i1 %obit, label %overflow, label %normal
6335</pre>
6336
6337</div>
6338
6339<!-- _______________________________________________________________________ -->
6340<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6341 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6342</div>
6343
6344<div class="doc_text">
6345
6346<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6347<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]6348 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6349
6350<pre>
6351 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6352 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6353 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6354</pre>
6355
6356<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6357<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6358 an unsigned addition of the two arguments, and indicate whether a carry
6359 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6360
6361<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6362<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]6363 be of integer types of any bit width, but they must have the same bit
6364 width. The second element of the result structure must be of
6365 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6366 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6367
6368<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6369<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6370 an unsigned addition of the two arguments. They return a structure &mdash;
6371 the first element of which is the sum, and the second element of which is a
6372 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6373
6374<h5>Examples:</h5>
6375<pre>
6376 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6377 %sum = extractvalue {i32, i1} %res, 0
6378 %obit = extractvalue {i32, i1} %res, 1
6379 br i1 %obit, label %carry, label %normal
6380</pre>
6381
6382</div>
6383
6384<!-- _______________________________________________________________________ -->
6385<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6386 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6387</div>
6388
6389<div class="doc_text">
6390
6391<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6392<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]6393 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6394
6395<pre>
6396 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6397 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6398 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6399</pre>
6400
6401<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6402<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6403 a signed subtraction of the two arguments, and indicate whether an overflow
6404 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6405
6406<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6407<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]6408 be of integer types of any bit width, but they must have the same bit
6409 width. The second element of the result structure must be of
6410 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6411 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6412
6413<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6414<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6415 a signed subtraction of the two arguments. They return a structure &mdash;
6416 the first element of which is the subtraction, and the second element of
6417 which is a bit specifying if the signed subtraction resulted in an
6418 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6419
6420<h5>Examples:</h5>
6421<pre>
6422 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6423 %sum = extractvalue {i32, i1} %res, 0
6424 %obit = extractvalue {i32, i1} %res, 1
6425 br i1 %obit, label %overflow, label %normal
6426</pre>
6427
6428</div>
6429
6430<!-- _______________________________________________________________________ -->
6431<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6432 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6433</div>
6434
6435<div class="doc_text">
6436
6437<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6438<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]6439 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6440
6441<pre>
6442 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6443 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6444 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6445</pre>
6446
6447<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6448<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6449 an unsigned subtraction of the two arguments, and indicate whether an
6450 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6451
6452<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6453<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]6454 be of integer types of any bit width, but they must have the same bit
6455 width. The second element of the result structure must be of
6456 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6457 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6458
6459<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6460<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6461 an unsigned subtraction of the two arguments. They return a structure &mdash;
6462 the first element of which is the subtraction, and the second element of
6463 which is a bit specifying if the unsigned subtraction resulted in an
6464 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6465
6466<h5>Examples:</h5>
6467<pre>
6468 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6469 %sum = extractvalue {i32, i1} %res, 0
6470 %obit = extractvalue {i32, i1} %res, 1
6471 br i1 %obit, label %overflow, label %normal
6472</pre>
6473
6474</div>
6475
6476<!-- _______________________________________________________________________ -->
6477<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6478 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6479</div>
6480
6481<div class="doc_text">
6482
6483<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6484<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]6485 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6486
6487<pre>
6488 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6489 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6490 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6491</pre>
6492
6493<h5>Overview:</h5>
6494
6495<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6496 a signed multiplication of the two arguments, and indicate whether an
6497 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6498
6499<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6500<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]6501 be of integer types of any bit width, but they must have the same bit
6502 width. The second element of the result structure must be of
6503 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6504 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6505
6506<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6507<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6508 a signed multiplication of the two arguments. They return a structure &mdash;
6509 the first element of which is the multiplication, and the second element of
6510 which is a bit specifying if the signed multiplication resulted in an
6511 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6512
6513<h5>Examples:</h5>
6514<pre>
6515 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6516 %sum = extractvalue {i32, i1} %res, 0
6517 %obit = extractvalue {i32, i1} %res, 1
6518 br i1 %obit, label %overflow, label %normal
6519</pre>
6520
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6521</div>
6522
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6523<!-- _______________________________________________________________________ -->
6524<div class="doc_subsubsection">
6525 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6526</div>
6527
6528<div class="doc_text">
6529
6530<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6531<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]6532 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6533
6534<pre>
6535 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6536 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6537 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6538</pre>
6539
6540<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6541<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6542 a unsigned multiplication of the two arguments, and indicate whether an
6543 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6544
6545<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6546<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]6547 be of integer types of any bit width, but they must have the same bit
6548 width. The second element of the result structure must be of
6549 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6550 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6551
6552<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6553<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6554 an unsigned multiplication of the two arguments. They return a structure
6555 &mdash; the first element of which is the multiplication, and the second
6556 element of which is a bit specifying if the unsigned multiplication resulted
6557 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6558
6559<h5>Examples:</h5>
6560<pre>
6561 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6562 %sum = extractvalue {i32, i1} %res, 0
6563 %obit = extractvalue {i32, i1} %res, 1
6564 br i1 %obit, label %overflow, label %normal
6565</pre>
6566
6567</div>
6568
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6569<!-- ======================================================================= -->
6570<div class="doc_subsection">
6571 <a name="int_debugger">Debugger Intrinsics</a>
6572</div>
6573
6574<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6575
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6576<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6577 prefix), are described in
6578 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6579 Level Debugging</a> document.</p>
6580
6581</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6582
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6583<!-- ======================================================================= -->
6584<div class="doc_subsection">
6585 <a name="int_eh">Exception Handling Intrinsics</a>
6586</div>
6587
6588<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6589
6590<p>The LLVM exception handling intrinsics (which all start with
6591 <tt>llvm.eh.</tt> prefix), are described in
6592 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6593 Handling</a> document.</p>
6594
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6595</div>
6596
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6597<!-- ======================================================================= -->
6598<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6599 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6600</div>
6601
6602<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6603
6604<p>This intrinsic makes it possible to excise one parameter, marked with
6605 the <tt>nest</tt> attribute, from a function. The result is a callable
6606 function pointer lacking the nest parameter - the caller does not need to
6607 provide a value for it. Instead, the value to use is stored in advance in a
6608 "trampoline", a block of memory usually allocated on the stack, which also
6609 contains code to splice the nest value into the argument list. This is used
6610 to implement the GCC nested function address extension.</p>
6611
6612<p>For example, if the function is
6613 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6614 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6615 follows:</p>
6616
6617<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6618<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6619 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6620 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6621 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6622 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6623</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6624</div>
6625
6626<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6627 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6628
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6629</div>
6630
6631<!-- _______________________________________________________________________ -->
6632<div class="doc_subsubsection">
6633 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6634</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6635
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6636<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6637
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6638<h5>Syntax:</h5>
6639<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640 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]6641</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6642
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6643<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6644<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6645 function pointer suitable for executing it.</p>
6646
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6647<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6648<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6649 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6650 sufficiently aligned block of memory; this memory is written to by the
6651 intrinsic. Note that the size and the alignment are target-specific - LLVM
6652 currently provides no portable way of determining them, so a front-end that
6653 generates this intrinsic needs to have some target-specific knowledge.
6654 The <tt>func</tt> argument must hold a function bitcast to
6655 an <tt>i8*</tt>.</p>
6656
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6657<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6658<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6659 dependent code, turning it into a function. A pointer to this function is
6660 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6661 function pointer type</a> before being called. The new function's signature
6662 is the same as that of <tt>func</tt> with any arguments marked with
6663 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6664 is allowed, and it must be of pointer type. Calling the new function is
6665 equivalent to calling <tt>func</tt> with the same argument list, but
6666 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6667 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6668 by <tt>tramp</tt> is modified, then the effect of any later call to the
6669 returned function pointer is undefined.</p>
6670
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6671</div>
6672
6673<!-- ======================================================================= -->
6674<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6675 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6676</div>
6677
6678<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6679
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6680<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6681 hardware constructs for atomic operations and memory synchronization. This
6682 provides an interface to the hardware, not an interface to the programmer. It
6683 is aimed at a low enough level to allow any programming models or APIs
6684 (Application Programming Interfaces) which need atomic behaviors to map
6685 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6686 hardware provides a "universal IR" for source languages, it also provides a
6687 starting point for developing a "universal" atomic operation and
6688 synchronization IR.</p>
6689
6690<p>These do <em>not</em> form an API such as high-level threading libraries,
6691 software transaction memory systems, atomic primitives, and intrinsic
6692 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6693 application libraries. The hardware interface provided by LLVM should allow
6694 a clean implementation of all of these APIs and parallel programming models.
6695 No one model or paradigm should be selected above others unless the hardware
6696 itself ubiquitously does so.</p>
6697
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6698</div>
6699
6700<!-- _______________________________________________________________________ -->
6701<div class="doc_subsubsection">
6702 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6703</div>
6704<div class="doc_text">
6705<h5>Syntax:</h5>
6706<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6707 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]6708</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6709
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6710<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6711<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6712 specific pairs of memory access types.</p>
6713
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6714<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6715<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6716 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame^]6717 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6718 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6719
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6720<ul>
6721 <li><tt>ll</tt>: load-load barrier</li>
6722 <li><tt>ls</tt>: load-store barrier</li>
6723 <li><tt>sl</tt>: store-load barrier</li>
6724 <li><tt>ss</tt>: store-store barrier</li>
6725 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6726</ul>
6727
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6728<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6729<p>This intrinsic causes the system to enforce some ordering constraints upon
6730 the loads and stores of the program. This barrier does not
6731 indicate <em>when</em> any events will occur, it only enforces
6732 an <em>order</em> in which they occur. For any of the specified pairs of load
6733 and store operations (f.ex. load-load, or store-load), all of the first
6734 operations preceding the barrier will complete before any of the second
6735 operations succeeding the barrier begin. Specifically the semantics for each
6736 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6737
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6738<ul>
6739 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6740 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6741 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6742 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6743 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6744 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6745 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6746 load after the barrier begins.</li>
6747</ul>
6748
6749<p>These semantics are applied with a logical "and" behavior when more than one
6750 is enabled in a single memory barrier intrinsic.</p>
6751
6752<p>Backends may implement stronger barriers than those requested when they do
6753 not support as fine grained a barrier as requested. Some architectures do
6754 not need all types of barriers and on such architectures, these become
6755 noops.</p>
6756
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6757<h5>Example:</h5>
6758<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6759%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6760%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6761 store i32 4, %ptr
6762
6763%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6764 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6765 <i>; guarantee the above finishes</i>
6766 store i32 8, %ptr <i>; before this begins</i>
6767</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6768
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6769</div>
6770
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6771<!-- _______________________________________________________________________ -->
6772<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6773 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6774</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6775
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6776<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6777
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6778<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6779<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6780 any integer bit width and for different address spaces. Not all targets
6781 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6782
6783<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6784 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6785 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6786 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6787 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]6788</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6789
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6790<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6791<p>This loads a value in memory and compares it to a given value. If they are
6792 equal, it stores a new value into the memory.</p>
6793
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6794<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6795<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6796 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6797 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6798 this integer type. While any bit width integer may be used, targets may only
6799 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6800
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6801<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6802<p>This entire intrinsic must be executed atomically. It first loads the value
6803 in memory pointed to by <tt>ptr</tt> and compares it with the
6804 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6805 memory. The loaded value is yielded in all cases. This provides the
6806 equivalent of an atomic compare-and-swap operation within the SSA
6807 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6808
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6809<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6810<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6811%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6812%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6813 store i32 4, %ptr
6814
6815%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6816%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6817 <i>; yields {i32}:result1 = 4</i>
6818%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6819%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6820
6821%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6822%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6823 <i>; yields {i32}:result2 = 8</i>
6824%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6825
6826%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6827</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6828
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6829</div>
6830
6831<!-- _______________________________________________________________________ -->
6832<div class="doc_subsubsection">
6833 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6834</div>
6835<div class="doc_text">
6836<h5>Syntax:</h5>
6837
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6838<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6839 integer bit width. Not all targets support all bit widths however.</p>
6840
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6841<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6842 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6843 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6844 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6845 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]6846</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6847
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6848<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6849<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6850 the value from memory. It then stores the value in <tt>val</tt> in the memory
6851 at <tt>ptr</tt>.</p>
6852
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6853<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6854<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6855 the <tt>val</tt> argument and the result must be integers of the same bit
6856 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6857 integer type. The targets may only lower integer representations they
6858 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6859
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6860<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6861<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6862 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6863 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6864
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6865<h5>Examples:</h5>
6866<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6867%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6868%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6869 store i32 4, %ptr
6870
6871%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6872%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6873 <i>; yields {i32}:result1 = 4</i>
6874%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6875%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6876
6877%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6878%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6879 <i>; yields {i32}:result2 = 8</i>
6880
6881%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6882%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6883</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6884
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6885</div>
6886
6887<!-- _______________________________________________________________________ -->
6888<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6889 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6890
6891</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6892
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6893<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6894
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6895<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6896<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6897 any integer bit width. Not all targets support all bit widths however.</p>
6898
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6899<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6900 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6901 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6902 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6903 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]6904</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6905
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6906<h5>Overview:</h5>
6907<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6908 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6909
6910<h5>Arguments:</h5>
6911<p>The intrinsic takes two arguments, the first a pointer to an integer value
6912 and the second an integer value. The result is also an integer value. These
6913 integer types can have any bit width, but they must all have the same bit
6914 width. The targets may only lower integer representations they support.</p>
6915
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6916<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6917<p>This intrinsic does a series of operations atomically. It first loads the
6918 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6919 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]6920
6921<h5>Examples:</h5>
6922<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6923%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6924%ptr = bitcast i8* %mallocP to i32*
6925 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6926%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6927 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6928%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6929 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6930%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6931 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6932%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6933</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6934
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6935</div>
6936
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6937<!-- _______________________________________________________________________ -->
6938<div class="doc_subsubsection">
6939 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6940
6941</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6942
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6943<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6944
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6945<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6946<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6947 any integer bit width and for different address spaces. Not all targets
6948 support all bit widths however.</p>
6949
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6950<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6951 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6952 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6953 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6954 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]6955</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6956
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6957<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6958<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6959 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6960
6961<h5>Arguments:</h5>
6962<p>The intrinsic takes two arguments, the first a pointer to an integer value
6963 and the second an integer value. The result is also an integer value. These
6964 integer types can have any bit width, but they must all have the same bit
6965 width. The targets may only lower integer representations they support.</p>
6966
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6967<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6968<p>This intrinsic does a series of operations atomically. It first loads the
6969 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6970 result to <tt>ptr</tt>. It yields the original value stored
6971 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6972
6973<h5>Examples:</h5>
6974<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6975%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6976%ptr = bitcast i8* %mallocP to i32*
6977 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6978%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6979 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6980%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6981 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6982%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6983 <i>; yields {i32}:result3 = 2</i>
6984%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6985</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6986
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6987</div>
6988
6989<!-- _______________________________________________________________________ -->
6990<div class="doc_subsubsection">
6991 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6992 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6993 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6994 <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]6995</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6996
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6997<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6998
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6999<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7000<p>These are overloaded intrinsics. You can
7001 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7002 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7003 bit width and for different address spaces. Not all targets support all bit
7004 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7005
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7006<pre>
7007 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7008 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7009 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7010 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]7011</pre>
7012
7013<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7014 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7015 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7016 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7017 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]7018</pre>
7019
7020<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7021 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7022 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7023 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7024 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]7025</pre>
7026
7027<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7028 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7029 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7030 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7031 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]7032</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7033
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7034<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7035<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7036 the value stored in memory at <tt>ptr</tt>. It yields the original value
7037 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7038
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7039<h5>Arguments:</h5>
7040<p>These intrinsics take two arguments, the first a pointer to an integer value
7041 and the second an integer value. The result is also an integer value. These
7042 integer types can have any bit width, but they must all have the same bit
7043 width. The targets may only lower integer representations they support.</p>
7044
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7045<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7046<p>These intrinsics does a series of operations atomically. They first load the
7047 value stored at <tt>ptr</tt>. They then do the bitwise
7048 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7049 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7050
7051<h5>Examples:</h5>
7052<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7053%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7054%ptr = bitcast i8* %mallocP to i32*
7055 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7056%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7057 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7058%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7059 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7060%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7061 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7062%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7063 <i>; yields {i32}:result3 = FF</i>
7064%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7065</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7066
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7067</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7068
7069<!-- _______________________________________________________________________ -->
7070<div class="doc_subsubsection">
7071 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7072 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7073 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7074 <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]7075</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7076
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7077<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7078
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7079<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7080<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7081 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7082 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7083 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7084
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7085<pre>
7086 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7087 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7088 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7089 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]7090</pre>
7091
7092<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7093 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7094 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7095 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7096 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]7097</pre>
7098
7099<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7100 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7101 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7102 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7103 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]7104</pre>
7105
7106<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7107 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7108 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7109 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7110 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]7111</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7112
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7113<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7114<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7115 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7116 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7117
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7118<h5>Arguments:</h5>
7119<p>These intrinsics take two arguments, the first a pointer to an integer value
7120 and the second an integer value. The result is also an integer value. These
7121 integer types can have any bit width, but they must all have the same bit
7122 width. The targets may only lower integer representations they support.</p>
7123
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7124<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7125<p>These intrinsics does a series of operations atomically. They first load the
7126 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7127 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7128 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7129
7130<h5>Examples:</h5>
7131<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7132%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7133%ptr = bitcast i8* %mallocP to i32*
7134 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7135%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7136 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7137%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7138 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7139%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7140 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7141%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7142 <i>; yields {i32}:result3 = 8</i>
7143%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7144</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7145
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7146</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7147
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7148
7149<!-- ======================================================================= -->
7150<div class="doc_subsection">
7151 <a name="int_memorymarkers">Memory Use Markers</a>
7152</div>
7153
7154<div class="doc_text">
7155
7156<p>This class of intrinsics exists to information about the lifetime of memory
7157 objects and ranges where variables are immutable.</p>
7158
7159</div>
7160
7161<!-- _______________________________________________________________________ -->
7162<div class="doc_subsubsection">
7163 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7164</div>
7165
7166<div class="doc_text">
7167
7168<h5>Syntax:</h5>
7169<pre>
7170 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7171</pre>
7172
7173<h5>Overview:</h5>
7174<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7175 object's lifetime.</p>
7176
7177<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7178<p>The first argument is a constant integer representing the size of the
7179 object, or -1 if it is variable sized. The second argument is a pointer to
7180 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7181
7182<h5>Semantics:</h5>
7183<p>This intrinsic indicates that before this point in the code, the value of the
7184 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]7185 never be used and has an undefined value. A load from the pointer that
7186 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7187 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7188
7189</div>
7190
7191<!-- _______________________________________________________________________ -->
7192<div class="doc_subsubsection">
7193 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7194</div>
7195
7196<div class="doc_text">
7197
7198<h5>Syntax:</h5>
7199<pre>
7200 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7201</pre>
7202
7203<h5>Overview:</h5>
7204<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7205 object's lifetime.</p>
7206
7207<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7208<p>The first argument is a constant integer representing the size of the
7209 object, or -1 if it is variable sized. The second argument is a pointer to
7210 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7211
7212<h5>Semantics:</h5>
7213<p>This intrinsic indicates that after this point in the code, the value of the
7214 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7215 never be used and has an undefined value. Any stores into the memory object
7216 following this intrinsic may be removed as dead.
7217
7218</div>
7219
7220<!-- _______________________________________________________________________ -->
7221<div class="doc_subsubsection">
7222 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7223</div>
7224
7225<div class="doc_text">
7226
7227<h5>Syntax:</h5>
7228<pre>
7229 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7230</pre>
7231
7232<h5>Overview:</h5>
7233<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7234 a memory object will not change.</p>
7235
7236<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7237<p>The first argument is a constant integer representing the size of the
7238 object, or -1 if it is variable sized. The second argument is a pointer to
7239 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7240
7241<h5>Semantics:</h5>
7242<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7243 the return value, the referenced memory location is constant and
7244 unchanging.</p>
7245
7246</div>
7247
7248<!-- _______________________________________________________________________ -->
7249<div class="doc_subsubsection">
7250 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7251</div>
7252
7253<div class="doc_text">
7254
7255<h5>Syntax:</h5>
7256<pre>
7257 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7258</pre>
7259
7260<h5>Overview:</h5>
7261<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7262 a memory object are mutable.</p>
7263
7264<h5>Arguments:</h5>
7265<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7266 The second argument is a constant integer representing the size of the
7267 object, or -1 if it is variable sized and the third argument is a pointer
7268 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7269
7270<h5>Semantics:</h5>
7271<p>This intrinsic indicates that the memory is mutable again.</p>
7272
7273</div>
7274
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7275<!-- ======================================================================= -->
7276<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7277 <a name="int_general">General Intrinsics</a>
7278</div>
7279
7280<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7281
7282<p>This class of intrinsics is designed to be generic and has no specific
7283 purpose.</p>
7284
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7285</div>
7286
7287<!-- _______________________________________________________________________ -->
7288<div class="doc_subsubsection">
7289 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7290</div>
7291
7292<div class="doc_text">
7293
7294<h5>Syntax:</h5>
7295<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]7296 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]7297</pre>
7298
7299<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7300<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7301
7302<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7303<p>The first argument is a pointer to a value, the second is a pointer to a
7304 global string, the third is a pointer to a global string which is the source
7305 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7306
7307<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7308<p>This intrinsic allows annotation of local variables with arbitrary strings.
7309 This can be useful for special purpose optimizations that want to look for
7310 these annotations. These have no other defined use, they are ignored by code
7311 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7312
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7313</div>
7314
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7315<!-- _______________________________________________________________________ -->
7316<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7317 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7318</div>
7319
7320<div class="doc_text">
7321
7322<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7323<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7324 any integer bit width.</p>
7325
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7326<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]7327 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7328 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7329 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7330 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7331 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]7332</pre>
7333
7334<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7335<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7336
7337<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7338<p>The first argument is an integer value (result of some expression), the
7339 second is a pointer to a global string, the third is a pointer to a global
7340 string which is the source file name, and the last argument is the line
7341 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7342
7343<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7344<p>This intrinsic allows annotations to be put on arbitrary expressions with
7345 arbitrary strings. This can be useful for special purpose optimizations that
7346 want to look for these annotations. These have no other defined use, they
7347 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7348
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7349</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7350
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7351<!-- _______________________________________________________________________ -->
7352<div class="doc_subsubsection">
7353 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7354</div>
7355
7356<div class="doc_text">
7357
7358<h5>Syntax:</h5>
7359<pre>
7360 declare void @llvm.trap()
7361</pre>
7362
7363<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7364<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7365
7366<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7367<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7368
7369<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7370<p>This intrinsics is lowered to the target dependent trap instruction. If the
7371 target does not have a trap instruction, this intrinsic will be lowered to
7372 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7373
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7374</div>
7375
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7376<!-- _______________________________________________________________________ -->
7377<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7378 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7379</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7380
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7381<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7382
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7383<h5>Syntax:</h5>
7384<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7385 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7386</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7387
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7388<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7389<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7390 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7391 ensure that it is placed on the stack before local variables.</p>
7392
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7393<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7394<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7395 arguments. The first argument is the value loaded from the stack
7396 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7397 that has enough space to hold the value of the guard.</p>
7398
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7399<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7400<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7401 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7402 stack. This is to ensure that if a local variable on the stack is
7403 overwritten, it will destroy the value of the guard. When the function exits,
7404 the guard on the stack is checked against the original guard. If they're
7405 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7406 function.</p>
7407
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7408</div>
7409
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7410<!-- _______________________________________________________________________ -->
7411<div class="doc_subsubsection">
7412 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7413</div>
7414
7415<div class="doc_text">
7416
7417<h5>Syntax:</h5>
7418<pre>
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7419 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7420 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7421</pre>
7422
7423<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7424<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopherd003c5b2010-01-08 21:42:39 +0000[diff] [blame]7425 to the optimizers to discover at compile time either a) when an
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7426 operation like memcpy will either overflow a buffer that corresponds to
7427 an object, or b) to determine that a runtime check for overflow isn't
7428 necessary. An object in this context means an allocation of a
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7429 specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7430
7431<h5>Arguments:</h5>
7432<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7433 argument is a pointer to or into the <tt>object</tt>. The second argument
7434 is a boolean 0 or 1. This argument determines whether you want the
7435 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7436 1, variables are not allowed.</p>
7437
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7438<h5>Semantics:</h5>
7439<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7440 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7441 (depending on the <tt>type</tt> argument if the size cannot be determined
7442 at compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7443
7444</div>
7445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7446<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7447<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7448<address>
7449 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7450 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7451 <a href="http://validator.w3.org/check/referer"><img
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7454 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7455 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
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