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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / d155945f15f73eb5619756d94e69b5bc5319d89a / . / docs / LangRef.html
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4<head>
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
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
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>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]58 <li><a href="#typesystem">Type System</a>
59 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]61 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]62 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]63 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]64 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]65 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_void">Void Type</a></li>
67 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]68 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 </ol>
70 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]71 <li><a href="#t_derived">Derived Types</a>
72 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]73 <li><a href="#t_aggregate">Aggregate Types</a>
74 <ol>
75 <li><a href="#t_array">Array Type</a></li>
76 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]77 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]78 <li><a href="#t_vector">Vector Type</a></li>
79 </ol>
80 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#t_function">Function Type</a></li>
82 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]83 </ol>
84 </li>
85 </ol>
86 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]87 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]88 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]89 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]90 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
92 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]93 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]94 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]95 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]96 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]97 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]98 <li><a href="#othervalues">Other Values</a>
99 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]100 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]101 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]102 </ol>
103 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]104 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
105 <ol>
106 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]107 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
108 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]109 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
110 Global Variable</a></li>
111 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
112 Global Variable</a></li>
113 </ol>
114 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]115 <li><a href="#instref">Instruction Reference</a>
116 <ol>
117 <li><a href="#terminators">Terminator Instructions</a>
118 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]119 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
120 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]122 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]125 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 </ol>
127 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]128 <li><a href="#binaryops">Binary Operations</a>
129 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]136 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
137 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
138 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]139 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
140 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
141 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]144 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
145 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]146 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
147 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
148 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]150 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]152 </ol>
153 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]154 <li><a href="#vectorops">Vector Operations</a>
155 <ol>
156 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
157 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
158 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]159 </ol>
160 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]161 <li><a href="#aggregateops">Aggregate Operations</a>
162 <ol>
163 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
164 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
165 </ol>
166 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]167 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]168 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]169 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]170 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
171 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
172 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]173 </ol>
174 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]175 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]176 <ol>
177 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
178 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
179 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]182 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
184 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]186 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
187 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]188 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]189 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]190 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]191 <li><a href="#otherops">Other Operations</a>
192 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]193 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
194 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]196 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]198 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></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 Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]203 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]204 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]205 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
206 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]207 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
208 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
213 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
215 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]219 <li><a href="#int_codegen">Code Generator Intrinsics</a>
220 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]221 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
222 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
224 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
225 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
226 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]227 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]228 </ol>
229 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]230 <li><a href="#int_libc">Standard C Library Intrinsics</a>
231 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]232 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]237 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]240 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]242 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]243 </ol>
244 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]245 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]246 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]247 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]248 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
249 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]251 </ol>
252 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]253 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
254 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]255 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
256 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
259 <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]260 <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]261 </ol>
262 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]263 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
264 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]265 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
266 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]267 </ol>
268 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]270 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]271 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]272 <ol>
273 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]274 </ol>
275 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]276 <li><a href="#int_atomics">Atomic intrinsics</a>
277 <ol>
278 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
279 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
280 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
281 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
282 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
283 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
284 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
285 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
286 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
287 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
288 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
289 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
290 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
291 </ol>
292 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]293 <li><a href="#int_memorymarkers">Memory Use Markers</a>
294 <ol>
295 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
296 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
297 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
298 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
299 </ol>
300 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]301 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]302 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]303 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]304 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]305 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]306 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]307 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]308 '<tt>llvm.trap</tt>' Intrinsic</a></li>
309 <li><a href="#int_stackprotector">
310 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]311 <li><a href="#int_objectsize">
312 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]313 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]314 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]315 </ol>
316 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]317</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]318
319<div class="doc_author">
320 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
321 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]322</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]324<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]325<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]327
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]328<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]329
330<p>This document is a reference manual for the LLVM assembly language. LLVM is
331 a Static Single Assignment (SSA) based representation that provides type
332 safety, low-level operations, flexibility, and the capability of representing
333 'all' high-level languages cleanly. It is the common code representation
334 used throughout all phases of the LLVM compilation strategy.</p>
335
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]338<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]339<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]340<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]341
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]342<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]343
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]344<p>The LLVM code representation is designed to be used in three different forms:
345 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
346 for fast loading by a Just-In-Time compiler), and as a human readable
347 assembly language representation. This allows LLVM to provide a powerful
348 intermediate representation for efficient compiler transformations and
349 analysis, while providing a natural means to debug and visualize the
350 transformations. The three different forms of LLVM are all equivalent. This
351 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]352
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]353<p>The LLVM representation aims to be light-weight and low-level while being
354 expressive, typed, and extensible at the same time. It aims to be a
355 "universal IR" of sorts, by being at a low enough level that high-level ideas
356 may be cleanly mapped to it (similar to how microprocessors are "universal
357 IR's", allowing many source languages to be mapped to them). By providing
358 type information, LLVM can be used as the target of optimizations: for
359 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]360 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]361 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]363<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]364<h4>
365 <a name="wellformed">Well-Formedness</a>
366</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]367
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]368<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]370<p>It is important to note that this document describes 'well formed' LLVM
371 assembly language. There is a difference between what the parser accepts and
372 what is considered 'well formed'. For example, the following instruction is
373 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]374
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]375<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]376%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]377</pre>
378
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]379<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
380 LLVM infrastructure provides a verification pass that may be used to verify
381 that an LLVM module is well formed. This pass is automatically run by the
382 parser after parsing input assembly and by the optimizer before it outputs
383 bitcode. The violations pointed out by the verifier pass indicate bugs in
384 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]385
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]386</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]387
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]388</div>
389
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]390<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]391
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]392<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]393<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]394<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]395
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]396<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]397
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]398<p>LLVM identifiers come in two basic types: global and local. Global
399 identifiers (functions, global variables) begin with the <tt>'@'</tt>
400 character. Local identifiers (register names, types) begin with
401 the <tt>'%'</tt> character. Additionally, there are three different formats
402 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]403
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]404<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]405 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]406 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
407 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
408 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
409 other characters in their names can be surrounded with quotes. Special
410 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
411 ASCII code for the character in hexadecimal. In this way, any character
412 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]413
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]414 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]415 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]416
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]417 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]418 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]419</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]421<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]422 don't need to worry about name clashes with reserved words, and the set of
423 reserved words may be expanded in the future without penalty. Additionally,
424 unnamed identifiers allow a compiler to quickly come up with a temporary
425 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]427<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]428 languages. There are keywords for different opcodes
429 ('<tt><a href="#i_add">add</a></tt>',
430 '<tt><a href="#i_bitcast">bitcast</a></tt>',
431 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
432 ('<tt><a href="#t_void">void</a></tt>',
433 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
434 reserved words cannot conflict with variable names, because none of them
435 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436
437<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]438 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]439
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]440<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]442<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]443%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444</pre>
445
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]446<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]448<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]452<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]453
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]454<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]455%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
456%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]457%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458</pre>
459
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]460<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
461 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]462
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]463<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]464 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]465 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]466
467 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]468 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]470 <li>Unnamed temporaries are numbered sequentially</li>
471</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]473<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]474 demonstrating instructions, we will follow an instruction with a comment that
475 defines the type and name of value produced. Comments are shown in italic
476 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]478</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]479
480<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]481<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]482<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]483<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]485<h3>
486 <a name="modulestructure">Module Structure</a>
487</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]488
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]489<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]491<p>LLVM programs are composed of "Module"s, each of which is a translation unit
492 of the input programs. Each module consists of functions, global variables,
493 and symbol table entries. Modules may be combined together with the LLVM
494 linker, which merges function (and global variable) definitions, resolves
495 forward declarations, and merges symbol table entries. Here is an example of
496 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]498<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]499<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]500<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]501
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]502<i>; External declaration of the puts function</i>&nbsp;
503<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]504
505<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]506define i32 @main() { <i>; i32()* </i>&nbsp;
507 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
508 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]510 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
511 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
512 <a href="#i_ret">ret</a> i32 0&nbsp;
513}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]514
515<i>; Named metadata</i>
516!1 = metadata !{i32 41}
517!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]518</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]519
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]520<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]521 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]522 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]523 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
524 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]525
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]526<p>In general, a module is made up of a list of global values, where both
527 functions and global variables are global values. Global values are
528 represented by a pointer to a memory location (in this case, a pointer to an
529 array of char, and a pointer to a function), and have one of the
530 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]531
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]532</div>
533
534<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]535<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]536 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]537</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]538
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]539<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]541<p>All Global Variables and Functions have one of the following types of
542 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]543
544<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]545 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]546 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
547 by objects in the current module. In particular, linking code into a
548 module with an private global value may cause the private to be renamed as
549 necessary to avoid collisions. Because the symbol is private to the
550 module, all references can be updated. This doesn't show up in any symbol
551 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]552
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]553 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]554 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
555 assembler and evaluated by the linker. Unlike normal strong symbols, they
556 are removed by the linker from the final linked image (executable or
557 dynamic library).</dd>
558
559 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
560 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
561 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
562 linker. The symbols are removed by the linker from the final linked image
563 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]564
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]565 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
566 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
567 of the object is not taken. For instance, functions that had an inline
568 definition, but the compiler decided not to inline it. Note,
569 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
570 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
571 visibility. The symbols are removed by the linker from the final linked
572 image (executable or dynamic library).</dd>
573
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]574 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]575 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]576 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
577 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]578
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]580 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]581 into the object file corresponding to the LLVM module. They exist to
582 allow inlining and other optimizations to take place given knowledge of
583 the definition of the global, which is known to be somewhere outside the
584 module. Globals with <tt>available_externally</tt> linkage are allowed to
585 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
586 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]587
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]588 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]589 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]590 the same name when linkage occurs. This can be used to implement
591 some forms of inline functions, templates, or other code which must be
592 generated in each translation unit that uses it, but where the body may
593 be overridden with a more definitive definition later. Unreferenced
594 <tt>linkonce</tt> globals are allowed to be discarded. Note that
595 <tt>linkonce</tt> linkage does not actually allow the optimizer to
596 inline the body of this function into callers because it doesn't know if
597 this definition of the function is the definitive definition within the
598 program or whether it will be overridden by a stronger definition.
599 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
600 linkage.</dd>
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_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]603 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
604 <tt>linkonce</tt> linkage, except that unreferenced globals with
605 <tt>weak</tt> linkage may not be discarded. This is used for globals that
606 are declared "weak" in C source code.</dd>
607
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]609 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
610 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
611 global scope.
612 Symbols with "<tt>common</tt>" linkage are merged in the same way as
613 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]614 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]615 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]616 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
617 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]618
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]619
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]620 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]621 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]622 pointer to array type. When two global variables with appending linkage
623 are linked together, the two global arrays are appended together. This is
624 the LLVM, typesafe, equivalent of having the system linker append together
625 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]626
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]627 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]628 <dd>The semantics of this linkage follow the ELF object file model: the symbol
629 is weak until linked, if not linked, the symbol becomes null instead of
630 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]631
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
633 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]634 <dd>Some languages allow differing globals to be merged, such as two functions
635 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]636 that only equivalent globals are ever merged (the "one definition rule"
637 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]638 and <tt>weak_odr</tt> linkage types to indicate that the global will only
639 be merged with equivalent globals. These linkage types are otherwise the
640 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]641
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]642 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]643 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]644 visible, meaning that it participates in linkage and can be used to
645 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]646</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]647
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]648<p>The next two types of linkage are targeted for Microsoft Windows platform
649 only. They are designed to support importing (exporting) symbols from (to)
650 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]651
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]652<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]653 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]654 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]655 or variable via a global pointer to a pointer that is set up by the DLL
656 exporting the symbol. On Microsoft Windows targets, the pointer name is
657 formed by combining <code>__imp_</code> and the function or variable
658 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]659
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]660 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]661 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]662 pointer to a pointer in a DLL, so that it can be referenced with the
663 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
664 name is formed by combining <code>__imp_</code> and the function or
665 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]666</dl>
667
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]668<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
669 another module defined a "<tt>.LC0</tt>" variable and was linked with this
670 one, one of the two would be renamed, preventing a collision. Since
671 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
672 declarations), they are accessible outside of the current module.</p>
673
674<p>It is illegal for a function <i>declaration</i> to have any linkage type
675 other than "externally visible", <tt>dllimport</tt>
676 or <tt>extern_weak</tt>.</p>
677
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]678<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]679 or <tt>weak_odr</tt> linkages.</p>
680
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]681</div>
682
683<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]684<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]685 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]686</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]687
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]688<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]689
690<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]691 and <a href="#i_invoke">invokes</a> can all have an optional calling
692 convention specified for the call. The calling convention of any pair of
693 dynamic caller/callee must match, or the behavior of the program is
694 undefined. The following calling conventions are supported by LLVM, and more
695 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]696
697<dl>
698 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]699 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]700 specified) matches the target C calling conventions. This calling
701 convention supports varargs function calls and tolerates some mismatch in
702 the declared prototype and implemented declaration of the function (as
703 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]704
705 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]706 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]707 (e.g. by passing things in registers). This calling convention allows the
708 target to use whatever tricks it wants to produce fast code for the
709 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]710 (Application Binary Interface).
711 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]712 when this or the GHC convention is used.</a> This calling convention
713 does not support varargs and requires the prototype of all callees to
714 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]715
716 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]717 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]718 as possible under the assumption that the call is not commonly executed.
719 As such, these calls often preserve all registers so that the call does
720 not break any live ranges in the caller side. This calling convention
721 does not support varargs and requires the prototype of all callees to
722 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]723
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]724 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
725 <dd>This calling convention has been implemented specifically for use by the
726 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
727 It passes everything in registers, going to extremes to achieve this by
728 disabling callee save registers. This calling convention should not be
729 used lightly but only for specific situations such as an alternative to
730 the <em>register pinning</em> performance technique often used when
731 implementing functional programming languages.At the moment only X86
732 supports this convention and it has the following limitations:
733 <ul>
734 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
735 floating point types are supported.</li>
736 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
737 6 floating point parameters.</li>
738 </ul>
739 This calling convention supports
740 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
741 requires both the caller and callee are using it.
742 </dd>
743
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]744 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]745 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]746 target-specific calling conventions to be used. Target specific calling
747 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]748</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]749
750<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]751 support Pascal conventions or any other well-known target-independent
752 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]753
754</div>
755
756<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]757<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]758 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]759</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]760
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]761<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]762
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]763<p>All Global Variables and Functions have one of the following visibility
764 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]765
766<dl>
767 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]768 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]769 that the declaration is visible to other modules and, in shared libraries,
770 means that the declared entity may be overridden. On Darwin, default
771 visibility means that the declaration is visible to other modules. Default
772 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]773
774 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]775 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]776 object if they are in the same shared object. Usually, hidden visibility
777 indicates that the symbol will not be placed into the dynamic symbol
778 table, so no other module (executable or shared library) can reference it
779 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]780
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]781 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]782 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]783 the dynamic symbol table, but that references within the defining module
784 will bind to the local symbol. That is, the symbol cannot be overridden by
785 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]786</dl>
787
788</div>
789
790<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]791<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]792 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]793</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]794
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]795<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]796
797<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]798 it easier to read the IR and make the IR more condensed (particularly when
799 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]800
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]801<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]802%mytype = type { %mytype*, i32 }
803</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]804
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]805<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]806 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]807 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]808
809<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]810 and that you can therefore specify multiple names for the same type. This
811 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
812 uses structural typing, the name is not part of the type. When printing out
813 LLVM IR, the printer will pick <em>one name</em> to render all types of a
814 particular shape. This means that if you have code where two different
815 source types end up having the same LLVM type, that the dumper will sometimes
816 print the "wrong" or unexpected type. This is an important design point and
817 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]818
819</div>
820
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]821<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]822<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]823 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]824</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]825
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]826<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]827
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]828<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]829 instead of run-time. Global variables may optionally be initialized, may
830 have an explicit section to be placed in, and may have an optional explicit
831 alignment specified. A variable may be defined as "thread_local", which
832 means that it will not be shared by threads (each thread will have a
833 separated copy of the variable). A variable may be defined as a global
834 "constant," which indicates that the contents of the variable
835 will <b>never</b> be modified (enabling better optimization, allowing the
836 global data to be placed in the read-only section of an executable, etc).
837 Note that variables that need runtime initialization cannot be marked
838 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]839
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]840<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
841 constant, even if the final definition of the global is not. This capability
842 can be used to enable slightly better optimization of the program, but
843 requires the language definition to guarantee that optimizations based on the
844 'constantness' are valid for the translation units that do not include the
845 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]846
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]847<p>As SSA values, global variables define pointer values that are in scope
848 (i.e. they dominate) all basic blocks in the program. Global variables
849 always define a pointer to their "content" type because they describe a
850 region of memory, and all memory objects in LLVM are accessed through
851 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]852
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]853<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
854 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]855 like this can be merged with other constants if they have the same
856 initializer. Note that a constant with significant address <em>can</em>
857 be merged with a <tt>unnamed_addr</tt> constant, the result being a
858 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]859
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]860<p>A global variable may be declared to reside in a target-specific numbered
861 address space. For targets that support them, address spaces may affect how
862 optimizations are performed and/or what target instructions are used to
863 access the variable. The default address space is zero. The address space
864 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]865
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]866<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]867 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]868
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]869<p>An explicit alignment may be specified for a global, which must be a power
870 of 2. If not present, or if the alignment is set to zero, the alignment of
871 the global is set by the target to whatever it feels convenient. If an
872 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]873 alignment. Targets and optimizers are not allowed to over-align the global
874 if the global has an assigned section. In this case, the extra alignment
875 could be observable: for example, code could assume that the globals are
876 densely packed in their section and try to iterate over them as an array,
877 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]878
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]879<p>For example, the following defines a global in a numbered address space with
880 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]881
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]882<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]883@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]884</pre>
885
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]886</div>
887
888
889<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]890<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]891 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]892</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]893
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]894<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]895
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]896<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]897 optional <a href="#linkage">linkage type</a>, an optional
898 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]899 <a href="#callingconv">calling convention</a>,
900 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]901 <a href="#paramattrs">parameter attribute</a> for the return type, a function
902 name, a (possibly empty) argument list (each with optional
903 <a href="#paramattrs">parameter attributes</a>), optional
904 <a href="#fnattrs">function attributes</a>, an optional section, an optional
905 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
906 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]907
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]908<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
909 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]910 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]911 <a href="#callingconv">calling convention</a>,
912 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]913 <a href="#paramattrs">parameter attribute</a> for the return type, a function
914 name, a possibly empty list of arguments, an optional alignment, and an
915 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]916
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]917<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]918 (Control Flow Graph) for the function. Each basic block may optionally start
919 with a label (giving the basic block a symbol table entry), contains a list
920 of instructions, and ends with a <a href="#terminators">terminator</a>
921 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]922
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]923<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]924 executed on entrance to the function, and it is not allowed to have
925 predecessor basic blocks (i.e. there can not be any branches to the entry
926 block of a function). Because the block can have no predecessors, it also
927 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]928
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]929<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]930 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]931
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]932<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]933 the alignment is set to zero, the alignment of the function is set by the
934 target to whatever it feels convenient. If an explicit alignment is
935 specified, the function is forced to have at least that much alignment. All
936 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]937
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]938<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
939 be significant and two identical functions can be merged</p>.
940
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]941<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]942<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]943define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]944 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
945 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
946 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
947 [<a href="#gc">gc</a>] { ... }
948</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]949
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]950</div>
951
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]952<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]953<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]954 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]955</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]956
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]957<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]958
959<p>Aliases act as "second name" for the aliasee value (which can be either
960 function, global variable, another alias or bitcast of global value). Aliases
961 may have an optional <a href="#linkage">linkage type</a>, and an
962 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]963
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]964<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]965<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]966@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]967</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]968
969</div>
970
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]971<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]972<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]973 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]974</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]975
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]976<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]977
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]978<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]979 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]980 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]981
982<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]983<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]984; Some unnamed metadata nodes, which are referenced by the named metadata.
985!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]986!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]987!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]988; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]989!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]990</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]991
992</div>
993
994<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]995<h3>
996 <a name="paramattrs">Parameter Attributes</a>
997</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]998
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]999<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1000
1001<p>The return type and each parameter of a function type may have a set of
1002 <i>parameter attributes</i> associated with them. Parameter attributes are
1003 used to communicate additional information about the result or parameters of
1004 a function. Parameter attributes are considered to be part of the function,
1005 not of the function type, so functions with different parameter attributes
1006 can have the same function type.</p>
1007
1008<p>Parameter attributes are simple keywords that follow the type specified. If
1009 multiple parameter attributes are needed, they are space separated. For
1010 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1011
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1012<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1013declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1014declare i32 @atoi(i8 zeroext)
1015declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1016</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1017
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1018<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1019 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1020
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1021<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1023<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1024 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1025 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1026 should be zero-extended to the extent required by the target's ABI (which
1027 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1028 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1029
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1030 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1031 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1032 should be sign-extended to the extent required by the target's ABI (which
1033 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1034 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1035
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1036 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This indicates that this parameter or return value should be treated in a
1038 special target-dependent fashion during while emitting code for a function
1039 call or return (usually, by putting it in a register as opposed to memory,
1040 though some targets use it to distinguish between two different kinds of
1041 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1042
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1043 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1044 <dd><p>This indicates that the pointer parameter should really be passed by
1045 value to the function. The attribute implies that a hidden copy of the
1046 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1047 is made between the caller and the callee, so the callee is unable to
1048 modify the value in the callee. This attribute is only valid on LLVM
1049 pointer arguments. It is generally used to pass structs and arrays by
1050 value, but is also valid on pointers to scalars. The copy is considered
1051 to belong to the caller not the callee (for example,
1052 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1053 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1054 values.</p>
1055
1056 <p>The byval attribute also supports specifying an alignment with
1057 the align attribute. It indicates the alignment of the stack slot to
1058 form and the known alignment of the pointer specified to the call site. If
1059 the alignment is not specified, then the code generator makes a
1060 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1061
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1062 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1063 <dd>This indicates that the pointer parameter specifies the address of a
1064 structure that is the return value of the function in the source program.
1065 This pointer must be guaranteed by the caller to be valid: loads and
1066 stores to the structure may be assumed by the callee to not to trap. This
1067 may only be applied to the first parameter. This is not a valid attribute
1068 for return values. </dd>
1069
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1070 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1071 <dd>This indicates that pointer values
1072 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1073 value do not alias pointer values which are not <i>based</i> on it,
1074 ignoring certain "irrelevant" dependencies.
1075 For a call to the parent function, dependencies between memory
1076 references from before or after the call and from those during the call
1077 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1078 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1079 The caller shares the responsibility with the callee for ensuring that
1080 these requirements are met.
1081 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1082 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1083<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1084 Note that this definition of <tt>noalias</tt> is intentionally
1085 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1086 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1087<br>
1088 For function return values, C99's <tt>restrict</tt> is not meaningful,
1089 while LLVM's <tt>noalias</tt> is.
1090 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1091
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1092 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1093 <dd>This indicates that the callee does not make any copies of the pointer
1094 that outlive the callee itself. This is not a valid attribute for return
1095 values.</dd>
1096
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1097 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1098 <dd>This indicates that the pointer parameter can be excised using the
1099 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1100 attribute for return values.</dd>
1101</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1102
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1103</div>
1104
1105<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1106<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1107 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1108</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1109
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1110<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1111
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1112<p>Each function may specify a garbage collector name, which is simply a
1113 string:</p>
1114
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1115<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1116define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1117</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1118
1119<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1120 collector which will cause the compiler to alter its output in order to
1121 support the named garbage collection algorithm.</p>
1122
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1123</div>
1124
1125<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1126<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1127 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1128</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1129
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1130<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1131
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1132<p>Function attributes are set to communicate additional information about a
1133 function. Function attributes are considered to be part of the function, not
1134 of the function type, so functions with different parameter attributes can
1135 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1137<p>Function attributes are simple keywords that follow the type specified. If
1138 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1139
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1140<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1141define void @f() noinline { ... }
1142define void @f() alwaysinline { ... }
1143define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1144define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1145</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1146
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1147<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1148 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1149 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1150 the backend should forcibly align the stack pointer. Specify the
1151 desired alignment, which must be a power of two, in parentheses.
1152
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1153 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1154 <dd>This attribute indicates that the inliner should attempt to inline this
1155 function into callers whenever possible, ignoring any active inlining size
1156 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1157
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1158 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1159 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1160 meaning the function can be patched and/or hooked even while it is
1161 loaded into memory. On x86, the function prologue will be preceded
1162 by six bytes of padding and will begin with a two-byte instruction.
1163 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1164 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1165
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1166 <dt><tt><b>nonlazybind</b></tt></dt>
1167 <dd>This attribute suppresses lazy symbol binding for the function. This
1168 may make calls to the function faster, at the cost of extra program
1169 startup time if the function is not called during program startup.</dd>
1170
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1171 <dt><tt><b>inlinehint</b></tt></dt>
1172 <dd>This attribute indicates that the source code contained a hint that inlining
1173 this function is desirable (such as the "inline" keyword in C/C++). It
1174 is just a hint; it imposes no requirements on the inliner.</dd>
1175
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1176 <dt><tt><b>naked</b></tt></dt>
1177 <dd>This attribute disables prologue / epilogue emission for the function.
1178 This can have very system-specific consequences.</dd>
1179
1180 <dt><tt><b>noimplicitfloat</b></tt></dt>
1181 <dd>This attributes disables implicit floating point instructions.</dd>
1182
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1183 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1184 <dd>This attribute indicates that the inliner should never inline this
1185 function in any situation. This attribute may not be used together with
1186 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1187
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1188 <dt><tt><b>noredzone</b></tt></dt>
1189 <dd>This attribute indicates that the code generator should not use a red
1190 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1191
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1192 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1193 <dd>This function attribute indicates that the function never returns
1194 normally. This produces undefined behavior at runtime if the function
1195 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1196
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This function attribute indicates that the function never returns with an
1199 unwind or exceptional control flow. If the function does unwind, its
1200 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1201
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1202 <dt><tt><b>optsize</b></tt></dt>
1203 <dd>This attribute suggests that optimization passes and code generator passes
1204 make choices that keep the code size of this function low, and otherwise
1205 do optimizations specifically to reduce code size.</dd>
1206
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1207 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1208 <dd>This attribute indicates that the function computes its result (or decides
1209 to unwind an exception) based strictly on its arguments, without
1210 dereferencing any pointer arguments or otherwise accessing any mutable
1211 state (e.g. memory, control registers, etc) visible to caller functions.
1212 It does not write through any pointer arguments
1213 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1214 changes any state visible to callers. This means that it cannot unwind
1215 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1216 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1217
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1218 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1219 <dd>This attribute indicates that the function does not write through any
1220 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1221 arguments) or otherwise modify any state (e.g. memory, control registers,
1222 etc) visible to caller functions. It may dereference pointer arguments
1223 and read state that may be set in the caller. A readonly function always
1224 returns the same value (or unwinds an exception identically) when called
1225 with the same set of arguments and global state. It cannot unwind an
1226 exception by calling the <tt>C++</tt> exception throwing methods, but may
1227 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1228
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1229 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1230 <dd>This attribute indicates that the function should emit a stack smashing
1231 protector. It is in the form of a "canary"&mdash;a random value placed on
1232 the stack before the local variables that's checked upon return from the
1233 function to see if it has been overwritten. A heuristic is used to
1234 determine if a function needs stack protectors or not.<br>
1235<br>
1236 If a function that has an <tt>ssp</tt> attribute is inlined into a
1237 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1238 function will have an <tt>ssp</tt> attribute.</dd>
1239
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1240 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1241 <dd>This attribute indicates that the function should <em>always</em> emit a
1242 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1243 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1244<br>
1245 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1246 function that doesn't have an <tt>sspreq</tt> attribute or which has
1247 an <tt>ssp</tt> attribute, then the resulting function will have
1248 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1249</dl>
1250
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1251</div>
1252
1253<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1254<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1255 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1256</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1257
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1258<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1259
1260<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1261 the GCC "file scope inline asm" blocks. These blocks are internally
1262 concatenated by LLVM and treated as a single unit, but may be separated in
1263 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1264
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1265<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1266module asm "inline asm code goes here"
1267module asm "more can go here"
1268</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1269
1270<p>The strings can contain any character by escaping non-printable characters.
1271 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]1272 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1273
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1274<p>The inline asm code is simply printed to the machine code .s file when
1275 assembly code is generated.</p>
1276
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1277</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1278
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1279<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1280<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1281 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1282</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1283
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1284<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1285
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1286<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1287 data is to be laid out in memory. The syntax for the data layout is
1288 simply:</p>
1289
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1290<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1291target datalayout = "<i>layout specification</i>"
1292</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1293
1294<p>The <i>layout specification</i> consists of a list of specifications
1295 separated by the minus sign character ('-'). Each specification starts with
1296 a letter and may include other information after the letter to define some
1297 aspect of the data layout. The specifications accepted are as follows:</p>
1298
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1299<dl>
1300 <dt><tt>E</tt></dt>
1301 <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]1302 bits with the most significance have the lowest address location.</dd>
1303
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1304 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1305 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1306 the bits with the least significance have the lowest address
1307 location.</dd>
1308
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1309 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1310 <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]1311 <i>preferred</i> alignments. All sizes are in bits. Specifying
1312 the <i>pref</i> alignment is optional. If omitted, the
1313 preceding <tt>:</tt> should be omitted too.</dd>
1314
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1315 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1316 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1317 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1318
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1319 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1320 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1321 <i>size</i>.</dd>
1322
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1323 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1324 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1325 <i>size</i>. Only values of <i>size</i> that are supported by the target
1326 will work. 32 (float) and 64 (double) are supported on all targets;
1327 80 or 128 (different flavors of long double) are also supported on some
1328 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1329
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1330 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1331 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1332 <i>size</i>.</dd>
1333
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1334 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1335 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1336 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1337
1338 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1339 <dd>This specifies a set of native integer widths for the target CPU
1340 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1341 "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]1342 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1343 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1344</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1345
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1346<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1347 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1348 specifications in the <tt>datalayout</tt> keyword. The default specifications
1349 are given in this list:</p>
1350
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1351<ul>
1352 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1353 <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]1354 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1355 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1356 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1357 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1358 <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]1359 alignment of 64-bits</li>
1360 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1361 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1362 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1363 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1364 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1365 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1366</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1367
1368<p>When LLVM is determining the alignment for a given type, it uses the
1369 following rules:</p>
1370
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1371<ol>
1372 <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]1373 specification is used.</li>
1374
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1375 <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]1376 smallest integer type that is larger than the bitwidth of the sought type
1377 is used. If none of the specifications are larger than the bitwidth then
1378 the the largest integer type is used. For example, given the default
1379 specifications above, the i7 type will use the alignment of i8 (next
1380 largest) while both i65 and i256 will use the alignment of i64 (largest
1381 specified).</li>
1382
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1383 <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]1384 largest vector type that is smaller than the sought vector type will be
1385 used as a fall back. This happens because &lt;128 x double&gt; can be
1386 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1387</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1388
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1389</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1390
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1391<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1392<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1393 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1394</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1395
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1396<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1397
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1398<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1399with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1400is undefined. Pointer values are associated with address ranges
1401according to the following rules:</p>
1402
1403<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1404 <li>A pointer value is associated with the addresses associated with
1405 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1406 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1407 range of the variable's storage.</li>
1408 <li>The result value of an allocation instruction is associated with
1409 the address range of the allocated storage.</li>
1410 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1411 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1412 <li>An integer constant other than zero or a pointer value returned
1413 from a function not defined within LLVM may be associated with address
1414 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1415 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1416 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1417</ul>
1418
1419<p>A pointer value is <i>based</i> on another pointer value according
1420 to the following rules:</p>
1421
1422<ul>
1423 <li>A pointer value formed from a
1424 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1425 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1426 <li>The result value of a
1427 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1428 of the <tt>bitcast</tt>.</li>
1429 <li>A pointer value formed by an
1430 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1431 pointer values that contribute (directly or indirectly) to the
1432 computation of the pointer's value.</li>
1433 <li>The "<i>based</i> on" relationship is transitive.</li>
1434</ul>
1435
1436<p>Note that this definition of <i>"based"</i> is intentionally
1437 similar to the definition of <i>"based"</i> in C99, though it is
1438 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1439
1440<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1441<tt><a href="#i_load">load</a></tt> merely indicates the size and
1442alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1443interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1444<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1445and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1446
1447<p>Consequently, type-based alias analysis, aka TBAA, aka
1448<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1449LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1450additional information which specialized optimization passes may use
1451to implement type-based alias analysis.</p>
1452
1453</div>
1454
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1455<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1456<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1457 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1458</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1459
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1460<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1461
1462<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1463href="#i_store"><tt>store</tt></a>s, and <a
1464href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1465The optimizers must not change the number of volatile operations or change their
1466order of execution relative to other volatile operations. The optimizers
1467<i>may</i> change the order of volatile operations relative to non-volatile
1468operations. This is not Java's "volatile" and has no cross-thread
1469synchronization behavior.</p>
1470
1471</div>
1472
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1473</div>
1474
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1475<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1476<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1477<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1478
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1479<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1480
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1481<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1482 intermediate representation. Being typed enables a number of optimizations
1483 to be performed on the intermediate representation directly, without having
1484 to do extra analyses on the side before the transformation. A strong type
1485 system makes it easier to read the generated code and enables novel analyses
1486 and transformations that are not feasible to perform on normal three address
1487 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1488
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1489<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1490<h3>
1491 <a name="t_classifications">Type Classifications</a>
1492</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1494<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1495
1496<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1497
1498<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1499 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1500 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1501 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1502 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1503 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1504 </tr>
1505 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1506 <td><a href="#t_floating">floating point</a></td>
1507 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1508 </tr>
1509 <tr>
1510 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1511 <td><a href="#t_integer">integer</a>,
1512 <a href="#t_floating">floating point</a>,
1513 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1514 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1515 <a href="#t_struct">structure</a>,
1516 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1517 <a href="#t_label">label</a>,
1518 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1519 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1520 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1521 <tr>
1522 <td><a href="#t_primitive">primitive</a></td>
1523 <td><a href="#t_label">label</a>,
1524 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1525 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1526 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1527 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1528 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1529 </tr>
1530 <tr>
1531 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1532 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1533 <a href="#t_function">function</a>,
1534 <a href="#t_pointer">pointer</a>,
1535 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1536 <a href="#t_vector">vector</a>,
1537 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1538 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1539 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1540 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1541</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1542
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1543<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1544 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1545 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1546
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1547</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1548
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1549<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1550<h3>
1551 <a name="t_primitive">Primitive Types</a>
1552</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1553
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1554<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1555
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1556<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1557 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1558
1559<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1560<h4>
1561 <a name="t_integer">Integer Type</a>
1562</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1563
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1564<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1565
1566<h5>Overview:</h5>
1567<p>The integer type is a very simple type that simply specifies an arbitrary
1568 bit width for the integer type desired. Any bit width from 1 bit to
1569 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1570
1571<h5>Syntax:</h5>
1572<pre>
1573 iN
1574</pre>
1575
1576<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1577 value.</p>
1578
1579<h5>Examples:</h5>
1580<table class="layout">
1581 <tr class="layout">
1582 <td class="left"><tt>i1</tt></td>
1583 <td class="left">a single-bit integer.</td>
1584 </tr>
1585 <tr class="layout">
1586 <td class="left"><tt>i32</tt></td>
1587 <td class="left">a 32-bit integer.</td>
1588 </tr>
1589 <tr class="layout">
1590 <td class="left"><tt>i1942652</tt></td>
1591 <td class="left">a really big integer of over 1 million bits.</td>
1592 </tr>
1593</table>
1594
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1595</div>
1596
1597<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1598<h4>
1599 <a name="t_floating">Floating Point Types</a>
1600</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1601
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1602<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1603
1604<table>
1605 <tbody>
1606 <tr><th>Type</th><th>Description</th></tr>
1607 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1608 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1609 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1610 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1611 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1612 </tbody>
1613</table>
1614
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1615</div>
1616
1617<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1618<h4>
1619 <a name="t_x86mmx">X86mmx Type</a>
1620</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1621
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1622<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1623
1624<h5>Overview:</h5>
1625<p>The x86mmx type represents a value held in an MMX register on an x86 machine. The operations allowed on it are quite limited: parameters and return values, load and store, and bitcast. User-specified MMX instructions are represented as intrinsic or asm calls with arguments and/or results of this type. There are no arrays, vectors or constants of this type.</p>
1626
1627<h5>Syntax:</h5>
1628<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1629 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1630</pre>
1631
1632</div>
1633
1634<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1635<h4>
1636 <a name="t_void">Void Type</a>
1637</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1638
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1639<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1640
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1641<h5>Overview:</h5>
1642<p>The void type does not represent any value and has no size.</p>
1643
1644<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1645<pre>
1646 void
1647</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1648
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1649</div>
1650
1651<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1652<h4>
1653 <a name="t_label">Label Type</a>
1654</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1655
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1656<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1657
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1658<h5>Overview:</h5>
1659<p>The label type represents code labels.</p>
1660
1661<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1662<pre>
1663 label
1664</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1665
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1666</div>
1667
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1668<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1669<h4>
1670 <a name="t_metadata">Metadata Type</a>
1671</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1672
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1673<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1674
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1675<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1676<p>The metadata type represents embedded metadata. No derived types may be
1677 created from metadata except for <a href="#t_function">function</a>
1678 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1679
1680<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1681<pre>
1682 metadata
1683</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1684
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1685</div>
1686
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1687</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1688
1689<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1690<h3>
1691 <a name="t_derived">Derived Types</a>
1692</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1693
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1694<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1695
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1696<p>The real power in LLVM comes from the derived types in the system. This is
1697 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1698 useful types. Each of these types contain one or more element types which
1699 may be a primitive type, or another derived type. For example, it is
1700 possible to have a two dimensional array, using an array as the element type
1701 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1702
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1703</div>
1704
1705
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1706<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1707<h4>
1708 <a name="t_aggregate">Aggregate Types</a>
1709</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1710
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1711<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1712
1713<p>Aggregate Types are a subset of derived types that can contain multiple
1714 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1715 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1716 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1717
1718</div>
1719
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1720<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1721<h4>
1722 <a name="t_array">Array Type</a>
1723</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1724
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1725<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1727<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1728<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1729 sequentially in memory. The array type requires a size (number of elements)
1730 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1731
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1732<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1733<pre>
1734 [&lt;# elements&gt; x &lt;elementtype&gt;]
1735</pre>
1736
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1737<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1738 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1739
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1740<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1741<table class="layout">
1742 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1743 <td class="left"><tt>[40 x i32]</tt></td>
1744 <td class="left">Array of 40 32-bit integer values.</td>
1745 </tr>
1746 <tr class="layout">
1747 <td class="left"><tt>[41 x i32]</tt></td>
1748 <td class="left">Array of 41 32-bit integer values.</td>
1749 </tr>
1750 <tr class="layout">
1751 <td class="left"><tt>[4 x i8]</tt></td>
1752 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1753 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1754</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1755<p>Here are some examples of multidimensional arrays:</p>
1756<table class="layout">
1757 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1758 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1759 <td class="left">3x4 array of 32-bit integer values.</td>
1760 </tr>
1761 <tr class="layout">
1762 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1763 <td class="left">12x10 array of single precision floating point values.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1767 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1768 </tr>
1769</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1770
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1771<p>There is no restriction on indexing beyond the end of the array implied by
1772 a static type (though there are restrictions on indexing beyond the bounds
1773 of an allocated object in some cases). This means that single-dimension
1774 'variable sized array' addressing can be implemented in LLVM with a zero
1775 length array type. An implementation of 'pascal style arrays' in LLVM could
1776 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1777
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1778</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1780<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1781<h4>
1782 <a name="t_function">Function Type</a>
1783</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1784
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1785<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1787<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1788<p>The function type can be thought of as a function signature. It consists of
1789 a return type and a list of formal parameter types. The return type of a
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1790 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1791
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1792<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1793<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1794 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1795</pre>
1796
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1797<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]1798 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1799 which indicates that the function takes a variable number of arguments.
1800 Variable argument functions can access their arguments with
1801 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1802 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1803 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1804
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1805<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1806<table class="layout">
1807 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1808 <td class="left"><tt>i32 (i32)</tt></td>
1809 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1810 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1811 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1812 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1813 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1814 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1815 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1816 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1817 </td>
1818 </tr><tr class="layout">
1819 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1820 <td class="left">A vararg function that takes at least one
1821 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1822 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1823 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1824 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1825 </tr><tr class="layout">
1826 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1827 <td class="left">A function taking an <tt>i32</tt>, returning a
1828 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1829 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1830 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1831</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1832
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1833</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1834
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1835<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1836<h4>
1837 <a name="t_struct">Structure Type</a>
1838</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1839
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1840<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1841
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1842<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1843<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1844 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1845
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1846<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1847 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1848 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1849 Structures in registers are accessed using the
1850 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1851 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1852
1853<p>Structures may optionally be "packed" structures, which indicate that the
1854 alignment of the struct is one byte, and that there is no padding between
1855 the elements. In non-packed structs, padding between field types is defined
1856 by the target data string to match the underlying processor.</p>
1857
1858<p>Structures can either be "anonymous" or "named". An anonymous structure is
1859 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1860 are always defined at the top level with a name. Anonmyous types are uniqued
1861 by their contents and can never be recursive since there is no way to write
1862 one. Named types can be recursive.
1863</p>
1864
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1865<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1866<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1867 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1868 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1869</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1870
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1871<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1872<table class="layout">
1873 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1874 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1875 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1876 </tr>
1877 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1878 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1879 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1880 second element is a <a href="#t_pointer">pointer</a> to a
1881 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1882 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1883 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1884 <tr class="layout">
1885 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1886 <td class="left">A packed struct known to be 5 bytes in size.</td>
1887 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1888</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1889
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1890</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1891
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1892<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1893<h4>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1894 <a name="t_opaque">Opaque Type</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1895</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1896
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1897<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1898
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1899<h5>Overview:</h5>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1900<p>Opaque types are used to represent named structure types that do not have a
1901 body specified. This corresponds (for example) to the C notion of a forward
1902 declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1903
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1904<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1905<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1906 %X = type opaque
1907 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1908</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1909
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1910<h5>Examples:</h5>
1911<table class="layout">
1912 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1913 <td class="left"><tt>opaque</tt></td>
1914 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1915 </tr>
1916</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1917
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1918</div>
1919
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1920
1921
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1922<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1923<h4>
1924 <a name="t_pointer">Pointer Type</a>
1925</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1926
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1927<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1928
1929<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1930<p>The pointer type is used to specify memory locations.
1931 Pointers are commonly used to reference objects in memory.</p>
1932
1933<p>Pointer types may have an optional address space attribute defining the
1934 numbered address space where the pointed-to object resides. The default
1935 address space is number zero. The semantics of non-zero address
1936 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937
1938<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1939 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1940
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1941<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1942<pre>
1943 &lt;type&gt; *
1944</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1945
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1946<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1947<table class="layout">
1948 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1949 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1950 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1951 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1952 </tr>
1953 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]1954 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1955 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1956 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1957 <tt>i32</tt>.</td>
1958 </tr>
1959 <tr class="layout">
1960 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1961 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1962 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1963 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1964</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1965
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1966</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1967
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1968<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1969<h4>
1970 <a name="t_vector">Vector Type</a>
1971</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1972
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1973<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1974
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1975<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1976<p>A vector type is a simple derived type that represents a vector of elements.
1977 Vector types are used when multiple primitive data are operated in parallel
1978 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1979 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1980 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1981
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1982<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1983<pre>
1984 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1985</pre>
1986
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]1987<p>The number of elements is a constant integer value larger than 0; elementtype
1988 may be any integer or floating point type. Vectors of size zero are not
1989 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1990
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1991<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1992<table class="layout">
1993 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1994 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1995 <td class="left">Vector of 4 32-bit integer values.</td>
1996 </tr>
1997 <tr class="layout">
1998 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1999 <td class="left">Vector of 8 32-bit floating-point values.</td>
2000 </tr>
2001 <tr class="layout">
2002 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2003 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2004 </tr>
2005</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2006
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2007</div>
2008
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2009<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2010<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2011<!-- *********************************************************************** -->
2012
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2013<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2014
2015<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2016 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2017
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2018<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2019<h3>
2020 <a name="simpleconstants">Simple Constants</a>
2021</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2022
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2023<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2024
2025<dl>
2026 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2027 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2028 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2029
2030 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2031 <dd>Standard integers (such as '4') are constants of
2032 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2033 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2034
2035 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2036 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2037 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2038 notation (see below). The assembler requires the exact decimal value of a
2039 floating-point constant. For example, the assembler accepts 1.25 but
2040 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2041 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2042
2043 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2044 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2045 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2046</dl>
2047
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2048<p>The one non-intuitive notation for constants is the hexadecimal form of
2049 floating point constants. For example, the form '<tt>double
2050 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2051 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2052 constants are required (and the only time that they are generated by the
2053 disassembler) is when a floating point constant must be emitted but it cannot
2054 be represented as a decimal floating point number in a reasonable number of
2055 digits. For example, NaN's, infinities, and other special values are
2056 represented in their IEEE hexadecimal format so that assembly and disassembly
2057 do not cause any bits to change in the constants.</p>
2058
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2059<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2060 represented using the 16-digit form shown above (which matches the IEEE754
2061 representation for double); float values must, however, be exactly
2062 representable as IEE754 single precision. Hexadecimal format is always used
2063 for long double, and there are three forms of long double. The 80-bit format
2064 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2065 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2066 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2067 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2068 currently supported target uses this format. Long doubles will only work if
2069 they match the long double format on your target. All hexadecimal formats
2070 are big-endian (sign bit at the left).</p>
2071
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2072<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2073</div>
2074
2075<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2076<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2077<a name="aggregateconstants"></a> <!-- old anchor -->
2078<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2079</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2080
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2081<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2082
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2083<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2084 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2085
2086<dl>
2087 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2088 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2089 type definitions (a comma separated list of elements, surrounded by braces
2090 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2091 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2092 Structure constants must have <a href="#t_struct">structure type</a>, and
2093 the number and types of elements must match those specified by the
2094 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2095
2096 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2097 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2098 definitions (a comma separated list of elements, surrounded by square
2099 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2100 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2101 the number and types of elements must match those specified by the
2102 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2103
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2104 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2105 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2106 definitions (a comma separated list of elements, surrounded by
2107 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2108 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2109 have <a href="#t_vector">vector type</a>, and the number and types of
2110 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2111
2112 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2113 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2114 value to zero of <em>any</em> type, including scalar and
2115 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2116 This is often used to avoid having to print large zero initializers
2117 (e.g. for large arrays) and is always exactly equivalent to using explicit
2118 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2119
2120 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2121 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2122 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2123 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2124 be interpreted as part of the instruction stream, metadata is a place to
2125 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2126</dl>
2127
2128</div>
2129
2130<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2131<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2132 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2133</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2134
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2135<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2137<p>The addresses of <a href="#globalvars">global variables</a>
2138 and <a href="#functionstructure">functions</a> are always implicitly valid
2139 (link-time) constants. These constants are explicitly referenced when
2140 the <a href="#identifiers">identifier for the global</a> is used and always
2141 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2142 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2143
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2144<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2145@X = global i32 17
2146@Y = global i32 42
2147@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2148</pre>
2149
2150</div>
2151
2152<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2153<h3>
2154 <a name="undefvalues">Undefined Values</a>
2155</h3>
2156
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2157<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2158
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2159<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]2160 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2161 Undefined values may be of any type (other than '<tt>label</tt>'
2162 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2163
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2164<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2165 program is well defined no matter what value is used. This gives the
2166 compiler more freedom to optimize. Here are some examples of (potentially
2167 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2168
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2169
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2170<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2171 %A = add %X, undef
2172 %B = sub %X, undef
2173 %C = xor %X, undef
2174Safe:
2175 %A = undef
2176 %B = undef
2177 %C = undef
2178</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2179
2180<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2181 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2182
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2183<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2184 %A = or %X, undef
2185 %B = and %X, undef
2186Safe:
2187 %A = -1
2188 %B = 0
2189Unsafe:
2190 %A = undef
2191 %B = undef
2192</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2193
2194<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2195 For example, if <tt>%X</tt> has a zero bit, then the output of the
2196 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2197 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2198 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2199 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2200 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2201 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2202 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2203
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2204<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2205 %A = select undef, %X, %Y
2206 %B = select undef, 42, %Y
2207 %C = select %X, %Y, undef
2208Safe:
2209 %A = %X (or %Y)
2210 %B = 42 (or %Y)
2211 %C = %Y
2212Unsafe:
2213 %A = undef
2214 %B = undef
2215 %C = undef
2216</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2217
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2218<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2219 branch) conditions can go <em>either way</em>, but they have to come from one
2220 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2221 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2222 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2223 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2224 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2225 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2226
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2227<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2228 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2229
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2230 %B = undef
2231 %C = xor %B, %B
2232
2233 %D = undef
2234 %E = icmp lt %D, 4
2235 %F = icmp gte %D, 4
2236
2237Safe:
2238 %A = undef
2239 %B = undef
2240 %C = undef
2241 %D = undef
2242 %E = undef
2243 %F = undef
2244</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2245
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2246<p>This example points out that two '<tt>undef</tt>' operands are not
2247 necessarily the same. This can be surprising to people (and also matches C
2248 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2249 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2250 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2251 its value over its "live range". This is true because the variable doesn't
2252 actually <em>have a live range</em>. Instead, the value is logically read
2253 from arbitrary registers that happen to be around when needed, so the value
2254 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2255 need to have the same semantics or the core LLVM "replace all uses with"
2256 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2257
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2258<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2259 %A = fdiv undef, %X
2260 %B = fdiv %X, undef
2261Safe:
2262 %A = undef
2263b: unreachable
2264</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2265
2266<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2267 value</em> and <em>undefined behavior</em>. An undefined value (like
2268 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2269 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2270 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2271 defined on SNaN's. However, in the second example, we can make a more
2272 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2273 arbitrary value, we are allowed to assume that it could be zero. Since a
2274 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2275 the operation does not execute at all. This allows us to delete the divide and
2276 all code after it. Because the undefined operation "can't happen", the
2277 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2278
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2279<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2280a: store undef -> %X
2281b: store %X -> undef
2282Safe:
2283a: &lt;deleted&gt;
2284b: unreachable
2285</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2286
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2287<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2288 undefined value can be assumed to not have any effect; we can assume that the
2289 value is overwritten with bits that happen to match what was already there.
2290 However, a store <em>to</em> an undefined location could clobber arbitrary
2291 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2292
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2293</div>
2294
2295<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2296<h3>
2297 <a name="trapvalues">Trap Values</a>
2298</h3>
2299
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2300<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2301
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2302<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2303 instead of representing an unspecified bit pattern, they represent the
2304 fact that an instruction or constant expression which cannot evoke side
2305 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2306 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2307
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2308<p>There is currently no way of representing a trap value in the IR; they
Dan Gohman855abed2010-05-03 14:51:43 +0000[diff] [blame]2309 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2310 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2311
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2312<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2313
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2314<ul>
2315<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2316 their operands.</li>
2317
2318<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2319 to their dynamic predecessor basic block.</li>
2320
2321<li>Function arguments depend on the corresponding actual argument values in
2322 the dynamic callers of their functions.</li>
2323
2324<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2325 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2326 control back to them.</li>
2327
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2328<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2329 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2330 or exception-throwing call instructions that dynamically transfer control
2331 back to them.</li>
2332
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2333<li>Non-volatile loads and stores depend on the most recent stores to all of the
2334 referenced memory addresses, following the order in the IR
2335 (including loads and stores implied by intrinsics such as
2336 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2337
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2338<!-- TODO: In the case of multiple threads, this only applies if the store
2339 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2340
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2341<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2342
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2343<li>An instruction with externally visible side effects depends on the most
2344 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2345 the order in the IR. (This includes
2346 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2347
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2348<li>An instruction <i>control-depends</i> on a
2349 <a href="#terminators">terminator instruction</a>
2350 if the terminator instruction has multiple successors and the instruction
2351 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2352 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2353
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2354<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2355 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2356 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2357 successor.</li>
2358
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2359<li>Dependence is transitive.</li>
2360
2361</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2362
2363<p>Whenever a trap value is generated, all values which depend on it evaluate
2364 to trap. If they have side effects, the evoke their side effects as if each
2365 operand with a trap value were undef. If they have externally-visible side
2366 effects, the behavior is undefined.</p>
2367
2368<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2369
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2370<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2371entry:
2372 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2373 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2374 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2375 store i32 0, i32* %trap_yet_again ; undefined behavior
2376
2377 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2378 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2379
2380 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2381
2382 %narrowaddr = bitcast i32* @g to i16*
2383 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2384 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2385 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2386
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2387 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2388 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2389
2390true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2391 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2392 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2393 br label %end
2394
2395end:
2396 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2397 ; Both edges into this PHI are
2398 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2399 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2400
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2401 volatile store i32 0, i32* @g ; This would depend on the store in %true
2402 ; if %cmp is true, or the store in %entry
2403 ; otherwise, so this is undefined behavior.
2404
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2405 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2406 ; The same branch again, but this time the
2407 ; true block doesn't have side effects.
2408
2409second_true:
2410 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2411 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2412
2413second_end:
2414 volatile store i32 0, i32* @g ; This time, the instruction always depends
2415 ; on the store in %end. Also, it is
2416 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2417 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2418 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2419</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2420
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2421</div>
2422
2423<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2424<h3>
2425 <a name="blockaddress">Addresses of Basic Blocks</a>
2426</h3>
2427
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2428<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2429
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2430<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2431
2432<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2433 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2434 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2435
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2436<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2437 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2438 comparisons against null. Pointer equality tests between labels addresses
2439 results in undefined behavior &mdash; though, again, comparison against null
2440 is ok, and no label is equal to the null pointer. This may be passed around
2441 as an opaque pointer sized value as long as the bits are not inspected. This
2442 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2443 long as the original value is reconstituted before the <tt>indirectbr</tt>
2444 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2445
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2446<p>Finally, some targets may provide defined semantics when using the value as
2447 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2448
2449</div>
2450
2451
2452<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2453<h3>
2454 <a name="constantexprs">Constant Expressions</a>
2455</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2456
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2457<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2458
2459<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2460 to be used as constants. Constant expressions may be of
2461 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2462 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2463 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2464
2465<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2466 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2467 <dd>Truncate a constant to another type. The bit size of CST must be larger
2468 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2469
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2470 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2471 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2472 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2473
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2474 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2475 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2476 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2477
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2478 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2479 <dd>Truncate a floating point constant to another floating point type. The
2480 size of CST must be larger than the size of TYPE. Both types must be
2481 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2482
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2483 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2484 <dd>Floating point extend a constant to another type. The size of CST must be
2485 smaller or equal to the size of TYPE. Both types must be floating
2486 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2487
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2488 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2489 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2490 constant. TYPE must be a scalar or vector integer type. CST must be of
2491 scalar or vector floating point type. Both CST and TYPE must be scalars,
2492 or vectors of the same number of elements. If the value won't fit in the
2493 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2494
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2495 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2496 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2497 constant. TYPE must be a scalar or vector integer type. CST must be of
2498 scalar or vector floating point type. Both CST and TYPE must be scalars,
2499 or vectors of the same number of elements. If the value won't fit in the
2500 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2501
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2502 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2503 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2504 constant. TYPE must be a scalar or vector floating point type. CST must be
2505 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2506 vectors of the same number of elements. If the value won't fit in the
2507 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2508
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2509 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2510 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2511 constant. TYPE must be a scalar or vector floating point type. CST must be
2512 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2513 vectors of the same number of elements. If the value won't fit in the
2514 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2515
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2516 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2517 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2518 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2519 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2520 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2521
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2522 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2523 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2524 type. CST must be of integer type. The CST value is zero extended,
2525 truncated, or unchanged to make it fit in a pointer size. This one is
2526 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2527
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2528 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2529 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2530 are the same as those for the <a href="#i_bitcast">bitcast
2531 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2532
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2533 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2534 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2535 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2536 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2537 instruction, the index list may have zero or more indexes, which are
2538 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2539
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2540 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2541 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2542
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2543 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2544 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2545
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2546 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2547 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2548
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2549 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2550 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2551 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2552
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2553 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2554 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2555 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2556
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2557 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2558 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2559 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2560
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2561 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2562 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2563 constants. The index list is interpreted in a similar manner as indices in
2564 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2565 index value must be specified.</dd>
2566
2567 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2568 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2569 constants. The index list is interpreted in a similar manner as indices in
2570 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2571 index value must be specified.</dd>
2572
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2573 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2574 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2575 be any of the <a href="#binaryops">binary</a>
2576 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2577 on operands are the same as those for the corresponding instruction
2578 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2579</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2580
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2581</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2582
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2583</div>
2584
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2585<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2586<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2587<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2588<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2589<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2590<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2591<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2592</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2593
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2594<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2595
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2596<p>LLVM supports inline assembler expressions (as opposed
2597 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2598 a special value. This value represents the inline assembler as a string
2599 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2600 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2601 expression has side effects, and a flag indicating whether the function
2602 containing the asm needs to align its stack conservatively. An example
2603 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2604
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2605<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2606i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2607</pre>
2608
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2609<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2610 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2611 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2612
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2613<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2614%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]2615</pre>
2616
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2617<p>Inline asms with side effects not visible in the constraint list must be
2618 marked as having side effects. This is done through the use of the
2619 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2620
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2621<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2622call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2623</pre>
2624
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2625<p>In some cases inline asms will contain code that will not work unless the
2626 stack is aligned in some way, such as calls or SSE instructions on x86,
2627 yet will not contain code that does that alignment within the asm.
2628 The compiler should make conservative assumptions about what the asm might
2629 contain and should generate its usual stack alignment code in the prologue
2630 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2631
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2632<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2633call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2634</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2635
2636<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2637 first.</p>
2638
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2639<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2640 documented here. Constraints on what can be done (e.g. duplication, moving,
2641 etc need to be documented). This is probably best done by reference to
2642 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2643
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2644<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2645<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2646</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2647
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2648<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2649
2650<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2651 attached to it that contains a list of constant integers. If present, the
2652 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2653 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2654 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2655 source code that produced it. For example:</p>
2656
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2657<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2658call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2659...
2660!42 = !{ i32 1234567 }
2661</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2662
2663<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2664 IR. If the MDNode contains multiple constants, the code generator will use
2665 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2666
2667</div>
2668
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2669</div>
2670
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2671<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2672<h3>
2673 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2674</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2675
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2676<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2677
2678<p>LLVM IR allows metadata to be attached to instructions in the program that
2679 can convey extra information about the code to the optimizers and code
2680 generator. One example application of metadata is source-level debug
2681 information. There are two metadata primitives: strings and nodes. All
2682 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2683 preceding exclamation point ('<tt>!</tt>').</p>
2684
2685<p>A metadata string is a string surrounded by double quotes. It can contain
2686 any character by escaping non-printable characters with "\xx" where "xx" is
2687 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2688
2689<p>Metadata nodes are represented with notation similar to structure constants
2690 (a comma separated list of elements, surrounded by braces and preceded by an
2691 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2692 10}</tt>". Metadata nodes can have any values as their operand.</p>
2693
2694<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2695 metadata nodes, which can be looked up in the module symbol table. For
2696 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2697
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2698<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2699 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2700
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2701<div class="doc_code">
2702<pre>
2703call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2704</pre>
2705</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2706
2707<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2708 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2709
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2710<div class="doc_code">
2711<pre>
2712%indvar.next = add i64 %indvar, 1, !dbg !21
2713</pre>
2714</div>
2715
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2716</div>
2717
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2718</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2719
2720<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2721<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2722 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2723</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2724<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2725<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2726<p>LLVM has a number of "magic" global variables that contain data that affect
2727code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2728of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2729section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2730by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2731
2732<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2733<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2734<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2735</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2736
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2737<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2738
2739<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2740href="#linkage_appending">appending linkage</a>. This array contains a list of
2741pointers to global variables and functions which may optionally have a pointer
2742cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2743
2744<pre>
2745 @X = global i8 4
2746 @Y = global i32 123
2747
2748 @llvm.used = appending global [2 x i8*] [
2749 i8* @X,
2750 i8* bitcast (i32* @Y to i8*)
2751 ], section "llvm.metadata"
2752</pre>
2753
2754<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2755compiler, assembler, and linker are required to treat the symbol as if there is
2756a reference to the global that it cannot see. For example, if a variable has
2757internal linkage and no references other than that from the <tt>@llvm.used</tt>
2758list, it cannot be deleted. This is commonly used to represent references from
2759inline asms and other things the compiler cannot "see", and corresponds to
2760"attribute((used))" in GNU C.</p>
2761
2762<p>On some targets, the code generator must emit a directive to the assembler or
2763object file to prevent the assembler and linker from molesting the symbol.</p>
2764
2765</div>
2766
2767<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2768<h3>
2769 <a name="intg_compiler_used">
2770 The '<tt>llvm.compiler.used</tt>' Global Variable
2771 </a>
2772</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2773
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2774<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2775
2776<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2777<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2778touching the symbol. On targets that support it, this allows an intelligent
2779linker to optimize references to the symbol without being impeded as it would be
2780by <tt>@llvm.used</tt>.</p>
2781
2782<p>This is a rare construct that should only be used in rare circumstances, and
2783should not be exposed to source languages.</p>
2784
2785</div>
2786
2787<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2788<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2789<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2790</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2791
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2792<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2793<pre>
2794%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2795@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2796</pre>
2797<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2798</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2799
2800</div>
2801
2802<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2803<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2804<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2805</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2806
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2807<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2808<pre>
2809%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2810@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2811</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2812
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2813<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2814</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2815
2816</div>
2817
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2818</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2819
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2820<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2821<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2822<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2823
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2824<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2825
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2826<p>The LLVM instruction set consists of several different classifications of
2827 instructions: <a href="#terminators">terminator
2828 instructions</a>, <a href="#binaryops">binary instructions</a>,
2829 <a href="#bitwiseops">bitwise binary instructions</a>,
2830 <a href="#memoryops">memory instructions</a>, and
2831 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2832
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2833<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2834<h3>
2835 <a name="terminators">Terminator Instructions</a>
2836</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2837
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2838<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2839
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2840<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2841 in a program ends with a "Terminator" instruction, which indicates which
2842 block should be executed after the current block is finished. These
2843 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2844 control flow, not values (the one exception being the
2845 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2846
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2847<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2848 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2849 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2850 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2851 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2852 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2853 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2854 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2855
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2856<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2857<h4>
2858 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2859</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2860
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2861<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2862
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2863<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2864<pre>
2865 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]2866 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2867</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2868
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2869<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2870<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2871 a value) from a function back to the caller.</p>
2872
2873<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2874 value and then causes control flow, and one that just causes control flow to
2875 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2876
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2877<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2878<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2879 return value. The type of the return value must be a
2880 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2881
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2882<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2883 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2884 value or a return value with a type that does not match its type, or if it
2885 has a void return type and contains a '<tt>ret</tt>' instruction with a
2886 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2887
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2888<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2889<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2890 the calling function's context. If the caller is a
2891 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2892 instruction after the call. If the caller was an
2893 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2894 the beginning of the "normal" destination block. If the instruction returns
2895 a value, that value shall set the call or invoke instruction's return
2896 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2897
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2898<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2899<pre>
2900 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2901 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2902 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]2903</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2904
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2905</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2906<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2907<h4>
2908 <a name="i_br">'<tt>br</tt>' Instruction</a>
2909</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2910
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2911<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2912
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2913<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2914<pre>
2915 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]2916</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2917
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2918<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2919<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2920 different basic block in the current function. There are two forms of this
2921 instruction, corresponding to a conditional branch and an unconditional
2922 branch.</p>
2923
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2924<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2925<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2926 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2927 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2928 target.</p>
2929
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2930<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2931<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2932 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2933 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2934 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2935
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2936<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2937<pre>
2938Test:
2939 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2940 br i1 %cond, label %IfEqual, label %IfUnequal
2941IfEqual:
2942 <a href="#i_ret">ret</a> i32 1
2943IfUnequal:
2944 <a href="#i_ret">ret</a> i32 0
2945</pre>
2946
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2947</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2948
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2949<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2950<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2951 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2952</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2953
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2954<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2955
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2956<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2957<pre>
2958 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2959</pre>
2960
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2961<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2962<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]2963 several different places. It is a generalization of the '<tt>br</tt>'
2964 instruction, allowing a branch to occur to one of many possible
2965 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2966
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2967<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2968<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2969 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2970 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2971 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2972
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2973<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2974<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2976 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2977 transferred to the corresponding destination; otherwise, control flow is
2978 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2979
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2980<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2981<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2982 <tt>switch</tt> instruction, this instruction may be code generated in
2983 different ways. For example, it could be generated as a series of chained
2984 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2985
2986<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2987<pre>
2988 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2989 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2990 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2991
2992 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2993 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2994
2995 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2996 switch i32 %val, label %otherwise [ i32 0, label %onzero
2997 i32 1, label %onone
2998 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2999</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3000
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3001</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3002
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3003
3004<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3005<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3006 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3007</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3008
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3009<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3010
3011<h5>Syntax:</h5>
3012<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3013 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]3014</pre>
3015
3016<h5>Overview:</h5>
3017
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3018<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3019 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3020 "<tt>address</tt>". Address must be derived from a <a
3021 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3022
3023<h5>Arguments:</h5>
3024
3025<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3026 rest of the arguments indicate the full set of possible destinations that the
3027 address may point to. Blocks are allowed to occur multiple times in the
3028 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3029
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3030<p>This destination list is required so that dataflow analysis has an accurate
3031 understanding of the CFG.</p>
3032
3033<h5>Semantics:</h5>
3034
3035<p>Control transfers to the block specified in the address argument. All
3036 possible destination blocks must be listed in the label list, otherwise this
3037 instruction has undefined behavior. This implies that jumps to labels
3038 defined in other functions have undefined behavior as well.</p>
3039
3040<h5>Implementation:</h5>
3041
3042<p>This is typically implemented with a jump through a register.</p>
3043
3044<h5>Example:</h5>
3045<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3046 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3047</pre>
3048
3049</div>
3050
3051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3052<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3053<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3054 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3055</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3056
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3057<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3058
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3059<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3060<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3061 &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]3062 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3063</pre>
3064
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3065<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3066<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3067 function, with the possibility of control flow transfer to either the
3068 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3069 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3070 control flow will return to the "normal" label. If the callee (or any
3071 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3072 instruction, control is interrupted and continued at the dynamically nearest
3073 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3074
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3075<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3076<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3077
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3078<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3079 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3080 convention</a> the call should use. If none is specified, the call
3081 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3082
3083 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3084 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3085 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3086
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3087 <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]3088 function value being invoked. In most cases, this is a direct function
3089 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3090 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3091
3092 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3093 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3094
3095 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3096 signature argument types and parameter attributes. All arguments must be
3097 of <a href="#t_firstclass">first class</a> type. If the function
3098 signature indicates the function accepts a variable number of arguments,
3099 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3100
3101 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3102 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3103
3104 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3105 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3106
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3107 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3108 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3109 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3110</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3111
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3112<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3113<p>This instruction is designed to operate as a standard
3114 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3115 primary difference is that it establishes an association with a label, which
3116 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3117
3118<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3119 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3120 exception. Additionally, this is important for implementation of
3121 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3122
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3123<p>For the purposes of the SSA form, the definition of the value returned by the
3124 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3125 block to the "normal" label. If the callee unwinds then no return value is
3126 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3127
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3128<p>Note that the code generator does not yet completely support unwind, and
3129that the invoke/unwind semantics are likely to change in future versions.</p>
3130
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3131<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3132<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3133 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3134 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3135 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3136 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3137</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3138
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3139</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3140
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3141<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3142
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3143<h4>
3144 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3145</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3146
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3147<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3148
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3149<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3150<pre>
3151 unwind
3152</pre>
3153
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3154<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3155<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3156 at the first callee in the dynamic call stack which used
3157 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3158 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3159
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3160<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3161<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3162 immediately halt. The dynamic call stack is then searched for the
3163 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3164 Once found, execution continues at the "exceptional" destination block
3165 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3166 instruction in the dynamic call chain, undefined behavior results.</p>
3167
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3168<p>Note that the code generator does not yet completely support unwind, and
3169that the invoke/unwind semantics are likely to change in future versions.</p>
3170
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3171</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3172
3173<!-- _______________________________________________________________________ -->
3174
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3175<h4>
3176 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3177</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3178
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3179<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3180
3181<h5>Syntax:</h5>
3182<pre>
3183 unreachable
3184</pre>
3185
3186<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3187<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3188 instruction is used to inform the optimizer that a particular portion of the
3189 code is not reachable. This can be used to indicate that the code after a
3190 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3191
3192<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3193<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3194
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3195</div>
3196
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3197</div>
3198
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3199<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3200<h3>
3201 <a name="binaryops">Binary Operations</a>
3202</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3203
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3204<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3205
3206<p>Binary operators are used to do most of the computation in a program. They
3207 require two operands of the same type, execute an operation on them, and
3208 produce a single value. The operands might represent multiple data, as is
3209 the case with the <a href="#t_vector">vector</a> data type. The result value
3210 has the same type as its operands.</p>
3211
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3212<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3213
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3214<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3215<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3216 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3217</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3218
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3219<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3220
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3221<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3222<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3223 &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]3224 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3225 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3226 &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]3227</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3228
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3229<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3230<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3231
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3232<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3233<p>The two arguments to the '<tt>add</tt>' instruction must
3234 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3235 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3236
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3237<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3238<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3239
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3240<p>If the sum has unsigned overflow, the result returned is the mathematical
3241 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]3242
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3243<p>Because LLVM integers use a two's complement representation, this instruction
3244 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3245
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3246<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3247 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3248 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3249 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3250 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3252<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3253<pre>
3254 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3255</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3256
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3257</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3258
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3259<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3260<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3261 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3262</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3263
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3264<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3265
3266<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3267<pre>
3268 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3269</pre>
3270
3271<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3272<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3273
3274<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3275<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3276 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3277 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3278
3279<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3280<p>The value produced is the floating point sum of the two operands.</p>
3281
3282<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3283<pre>
3284 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3285</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3286
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3287</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3288
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3289<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3290<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3291 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3292</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3293
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3294<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3297<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3298 &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]3299 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3300 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3301 &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]3302</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3303
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3304<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3305<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3306 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3307
3308<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3309 '<tt>neg</tt>' instruction present in most other intermediate
3310 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3311
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3312<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3313<p>The two arguments to the '<tt>sub</tt>' instruction must
3314 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3315 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3316
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3317<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3318<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3319
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3320<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3321 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3322 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3323
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3324<p>Because LLVM integers use a two's complement representation, this instruction
3325 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3326
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3327<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3328 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3329 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3330 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3331 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3332
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3333<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3334<pre>
3335 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3336 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3337</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3338
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3339</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3340
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3341<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3342<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3343 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3344</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3345
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3346<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3347
3348<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3349<pre>
3350 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3351</pre>
3352
3353<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3354<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3355 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3356
3357<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3358 '<tt>fneg</tt>' instruction present in most other intermediate
3359 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3360
3361<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3362<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3364 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3365
3366<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3367<p>The value produced is the floating point difference of the two operands.</p>
3368
3369<h5>Example:</h5>
3370<pre>
3371 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3372 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3373</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3375</div>
3376
3377<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3378<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3379 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3380</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3381
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3382<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3386 &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]3387 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3388 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3389 &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]3390</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3391
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3392<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3393<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3394
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3395<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3396<p>The two arguments to the '<tt>mul</tt>' instruction must
3397 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3398 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3400<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3401<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3402
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3403<p>If the result of the multiplication has unsigned overflow, the result
3404 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3405 width of the result.</p>
3406
3407<p>Because LLVM integers use a two's complement representation, and the result
3408 is the same width as the operands, this instruction returns the correct
3409 result for both signed and unsigned integers. If a full product
3410 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3411 be sign-extended or zero-extended as appropriate to the width of the full
3412 product.</p>
3413
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3414<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3415 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3416 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3417 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3418 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3419
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3420<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3421<pre>
3422 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3423</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3424
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3425</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3426
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3427<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3428<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3429 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3430</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3431
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3432<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3433
3434<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3435<pre>
3436 &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]3437</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3438
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3439<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3440<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3441
3442<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3443<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3444 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3445 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3446
3447<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3448<p>The value produced is the floating point product of the two operands.</p>
3449
3450<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3451<pre>
3452 &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]3453</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3454
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3455</div>
3456
3457<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3458<h4>
3459 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3460</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3461
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3462<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3463
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3464<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3465<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3466 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3467 &lt;result&gt; = udiv 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]3468</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3469
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3470<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3471<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3472
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3473<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3474<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3475 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3476 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3477
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3478<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3479<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3480
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3481<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3482 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3483
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3484<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3485
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3486<p>If the <tt>exact</tt> keyword is present, the result value of the
3487 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3488 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3489
3490
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3491<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3492<pre>
3493 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3494</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3495
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3496</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3497
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3498<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3499<h4>
3500 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3501</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3502
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3503<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3504
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3505<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3506<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3507 &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]3508 &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]3509</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3510
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3511<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3512<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3513
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3514<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3515<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3516 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3517 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3518
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3519<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3520<p>The value produced is the signed integer quotient of the two operands rounded
3521 towards zero.</p>
3522
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3523<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3524 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3525
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3526<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3527 undefined behavior; this is a rare case, but can occur, for example, by doing
3528 a 32-bit division of -2147483648 by -1.</p>
3529
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3530<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3531 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohman38da9272010-07-11 00:08:34 +0000[diff] [blame]3532 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3533
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3534<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3535<pre>
3536 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3537</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3538
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3539</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3540
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3541<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3542<h4>
3543 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3544</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3545
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3546<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3547
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3548<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3549<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3550 &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]3551</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3552
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3553<h5>Overview:</h5>
3554<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3555
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3556<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3557<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3558 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3559 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3560
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3561<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3562<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3563
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3564<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3565<pre>
3566 &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]3567</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3568
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3569</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3570
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3571<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3572<h4>
3573 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3574</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3575
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3576<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3577
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3578<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3579<pre>
3580 &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]3581</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3582
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3583<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3584<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3585 division of its two arguments.</p>
3586
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3587<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3588<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3589 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3590 values. Both arguments must have identical types.</p>
3591
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3592<h5>Semantics:</h5>
3593<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3594 This instruction always performs an unsigned division to get the
3595 remainder.</p>
3596
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3597<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3598 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3599
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3600<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3601
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3602<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3603<pre>
3604 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3605</pre>
3606
3607</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3608
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3609<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3610<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3611 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3612</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3613
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3614<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3615
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3616<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3617<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3618 &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]3619</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3620
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3621<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3622<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3623 division of its two operands. This instruction can also take
3624 <a href="#t_vector">vector</a> versions of the values in which case the
3625 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3626
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3627<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3628<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3629 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3630 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3631
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3632<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3633<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3634 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3635 <i>modulo</i> operator (where the result is either zero or has the same sign
3636 as the divisor, <tt>op2</tt>) of a value.
3637 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3638 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3639 Math Forum</a>. For a table of how this is implemented in various languages,
3640 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3641 Wikipedia: modulo operation</a>.</p>
3642
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3643<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3644 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3645
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3646<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3647 Overflow also leads to undefined behavior; this is a rare case, but can
3648 occur, for example, by taking the remainder of a 32-bit division of
3649 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3650 lets srem be implemented using instructions that return both the result of
3651 the division and the remainder.)</p>
3652
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3653<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3654<pre>
3655 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3656</pre>
3657
3658</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3659
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3660<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3661<h4>
3662 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3663</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3664
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3665<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3666
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3667<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &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]3670</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3671
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3672<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3674 its two operands.</p>
3675
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3676<h5>Arguments:</h5>
3677<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3678 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3679 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3680
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3681<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682<p>This instruction returns the <i>remainder</i> of a division. The remainder
3683 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3684
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3685<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3686<pre>
3687 &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]3688</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3689
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3690</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3691
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3692</div>
3693
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3694<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3695<h3>
3696 <a name="bitwiseops">Bitwise Binary Operations</a>
3697</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3698
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3699<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3700
3701<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3702 program. They are generally very efficient instructions and can commonly be
3703 strength reduced from other instructions. They require two operands of the
3704 same type, execute an operation on them, and produce a single value. The
3705 resulting value is the same type as its operands.</p>
3706
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3707<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3708<h4>
3709 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3710</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3711
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3712<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3713
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3714<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3715<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3716 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3717 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3718 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3719 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3720</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3721
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3722<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3723<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3724 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3725
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3726<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3727<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3728 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3729 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3730
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3731<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3732<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3733 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3734 is (statically or dynamically) negative or equal to or larger than the number
3735 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3736 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3737 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3738
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3739<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3740 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattner66298c12011-02-09 16:44:44 +0000[diff] [blame]3741 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3742 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3743 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3744 they would if the shift were expressed as a mul instruction with the same
3745 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3746
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3747<h5>Example:</h5>
3748<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3749 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3750 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3751 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3752 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3753 &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]3754</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3755
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3756</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3758<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3759<h4>
3760 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3761</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3762
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3763<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3764
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3765<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3766<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3767 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3768 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3769</pre>
3770
3771<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3772<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3773 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3774
3775<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3776<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3777 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3778 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3779
3780<h5>Semantics:</h5>
3781<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3782 significant bits of the result will be filled with zero bits after the shift.
3783 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3784 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3785 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3786 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3787
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3788<p>If the <tt>exact</tt> keyword is present, the result value of the
3789 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3790 shifted out are non-zero.</p>
3791
3792
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3793<h5>Example:</h5>
3794<pre>
3795 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3796 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3797 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3798 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3799 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3800 &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]3801</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3803</div>
3804
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3805<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3806<h4>
3807 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3808</h4>
3809
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3810<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3811
3812<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3813<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3814 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3815 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3816</pre>
3817
3818<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3819<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3820 operand shifted to the right a specified number of bits with sign
3821 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3822
3823<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3824<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3826 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3827
3828<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3829<p>This instruction always performs an arithmetic shift right operation, The
3830 most significant bits of the result will be filled with the sign bit
3831 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3832 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3833 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3834 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3835
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3836<p>If the <tt>exact</tt> keyword is present, the result value of the
3837 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3838 shifted out are non-zero.</p>
3839
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3840<h5>Example:</h5>
3841<pre>
3842 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3843 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3844 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3845 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3846 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3847 &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]3848</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3849
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3850</div>
3851
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3852<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3853<h4>
3854 <a name="i_and">'<tt>and</tt>' Instruction</a>
3855</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3856
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3857<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3859<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3860<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3861 &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]3862</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3863
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3864<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3865<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3866 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3867
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3868<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3869<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3870 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3871 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3872
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3873<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3874<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3875
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3876<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3877 <tbody>
3878 <tr>
3879 <td>In0</td>
3880 <td>In1</td>
3881 <td>Out</td>
3882 </tr>
3883 <tr>
3884 <td>0</td>
3885 <td>0</td>
3886 <td>0</td>
3887 </tr>
3888 <tr>
3889 <td>0</td>
3890 <td>1</td>
3891 <td>0</td>
3892 </tr>
3893 <tr>
3894 <td>1</td>
3895 <td>0</td>
3896 <td>0</td>
3897 </tr>
3898 <tr>
3899 <td>1</td>
3900 <td>1</td>
3901 <td>1</td>
3902 </tr>
3903 </tbody>
3904</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3905
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3906<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3907<pre>
3908 &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]3909 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3910 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3911</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3912</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3913<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3914<h4>
3915 <a name="i_or">'<tt>or</tt>' Instruction</a>
3916</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3917
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3918<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3919
3920<h5>Syntax:</h5>
3921<pre>
3922 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3923</pre>
3924
3925<h5>Overview:</h5>
3926<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3927 two operands.</p>
3928
3929<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3930<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3931 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3932 values. Both arguments must have identical types.</p>
3933
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3934<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3935<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3936
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3937<table border="1" cellspacing="0" cellpadding="4">
3938 <tbody>
3939 <tr>
3940 <td>In0</td>
3941 <td>In1</td>
3942 <td>Out</td>
3943 </tr>
3944 <tr>
3945 <td>0</td>
3946 <td>0</td>
3947 <td>0</td>
3948 </tr>
3949 <tr>
3950 <td>0</td>
3951 <td>1</td>
3952 <td>1</td>
3953 </tr>
3954 <tr>
3955 <td>1</td>
3956 <td>0</td>
3957 <td>1</td>
3958 </tr>
3959 <tr>
3960 <td>1</td>
3961 <td>1</td>
3962 <td>1</td>
3963 </tr>
3964 </tbody>
3965</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3966
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3967<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3968<pre>
3969 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3970 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3971 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3972</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3973
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3974</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3975
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3976<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3977<h4>
3978 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
3979</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3980
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3981<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3982
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3983<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3984<pre>
3985 &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]3986</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3987
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3988<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3989<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3990 its two operands. The <tt>xor</tt> is used to implement the "one's
3991 complement" operation, which is the "~" operator in C.</p>
3992
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3993<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3994<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3995 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3996 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3997
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3998<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3999<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4000
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4001<table border="1" cellspacing="0" cellpadding="4">
4002 <tbody>
4003 <tr>
4004 <td>In0</td>
4005 <td>In1</td>
4006 <td>Out</td>
4007 </tr>
4008 <tr>
4009 <td>0</td>
4010 <td>0</td>
4011 <td>0</td>
4012 </tr>
4013 <tr>
4014 <td>0</td>
4015 <td>1</td>
4016 <td>1</td>
4017 </tr>
4018 <tr>
4019 <td>1</td>
4020 <td>0</td>
4021 <td>1</td>
4022 </tr>
4023 <tr>
4024 <td>1</td>
4025 <td>1</td>
4026 <td>0</td>
4027 </tr>
4028 </tbody>
4029</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4030
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4031<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4032<pre>
4033 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4034 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4035 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4036 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4037</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4038
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4039</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4040
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4041</div>
4042
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4043<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4044<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4045 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4046</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4047
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4048<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4049
4050<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4051 target-independent manner. These instructions cover the element-access and
4052 vector-specific operations needed to process vectors effectively. While LLVM
4053 does directly support these vector operations, many sophisticated algorithms
4054 will want to use target-specific intrinsics to take full advantage of a
4055 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4056
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4057<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4058<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4059 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4060</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4061
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4062<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4063
4064<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4065<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4066 &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]4067</pre>
4068
4069<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4070<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4071 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4072
4073
4074<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4075<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4076 of <a href="#t_vector">vector</a> type. The second operand is an index
4077 indicating the position from which to extract the element. The index may be
4078 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4079
4080<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4081<p>The result is a scalar of the same type as the element type of
4082 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4083 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4084 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4085
4086<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4087<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4088 &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]4089</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4090
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4091</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4092
4093<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4094<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4095 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4096</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4097
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4098<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4099
4100<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4101<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4102 &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]4103</pre>
4104
4105<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4106<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4107 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4108
4109<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4110<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4111 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4112 whose type must equal the element type of the first operand. The third
4113 operand is an index indicating the position at which to insert the value.
4114 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4115
4116<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4117<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4118 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4119 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4120 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4121
4122<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4123<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4124 &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]4125</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4126
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4127</div>
4128
4129<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4130<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4131 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4132</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4133
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4134<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4135
4136<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4137<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4138 &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]4139</pre>
4140
4141<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4142<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4143 from two input vectors, returning a vector with the same element type as the
4144 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4145
4146<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4148 with types that match each other. The third argument is a shuffle mask whose
4149 element type is always 'i32'. The result of the instruction is a vector
4150 whose length is the same as the shuffle mask and whose element type is the
4151 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4152
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4153<p>The shuffle mask operand is required to be a constant vector with either
4154 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4155
4156<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4157<p>The elements of the two input vectors are numbered from left to right across
4158 both of the vectors. The shuffle mask operand specifies, for each element of
4159 the result vector, which element of the two input vectors the result element
4160 gets. The element selector may be undef (meaning "don't care") and the
4161 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4162
4163<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4164<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4165 &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]4166 &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]4167 &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]4168 &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]4169 &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]4170 &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]4171 &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]4172 &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]4173</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4174
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4175</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4176
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4177</div>
4178
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4179<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4180<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4181 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4182</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4183
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4184<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4185
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4186<p>LLVM supports several instructions for working with
4187 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4188
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4189<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4190<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4191 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4192</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4193
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4194<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4195
4196<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4197<pre>
4198 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4199</pre>
4200
4201<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4202<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4203 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4204
4205<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4206<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4207 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4208 <a href="#t_array">array</a> type. The operands are constant indices to
4209 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4210 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4211 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4212 <ul>
4213 <li>Since the value being indexed is not a pointer, the first index is
4214 omitted and assumed to be zero.</li>
4215 <li>At least one index must be specified.</li>
4216 <li>Not only struct indices but also array indices must be in
4217 bounds.</li>
4218 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4219
4220<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4221<p>The result is the value at the position in the aggregate specified by the
4222 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4223
4224<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4225<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4226 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4227</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4228
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4229</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4230
4231<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4232<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4233 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4234</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4235
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4236<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4237
4238<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4239<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4240 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4241</pre>
4242
4243<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4244<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4245 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4246
4247<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4248<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4249 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4250 <a href="#t_array">array</a> type. The second operand is a first-class
4251 value to insert. The following operands are constant indices indicating
4252 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4253 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4254 value to insert must have the same type as the value identified by the
4255 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4256
4257<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4258<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4259 that of <tt>val</tt> except that the value at the position specified by the
4260 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4261
4262<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4263<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4264 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4265 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4266 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4267</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4268
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4269</div>
4270
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4271</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4272
4273<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4274<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4275 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4276</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4277
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4278<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4279
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4280<p>A key design point of an SSA-based representation is how it represents
4281 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4282 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4283 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4284
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4285<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4286<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4287 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4288</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4289
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4290<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4291
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4292<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4293<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4294 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4295</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4297<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4298<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4299 currently executing function, to be automatically released when this function
4300 returns to its caller. The object is always allocated in the generic address
4301 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4303<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4304<p>The '<tt>alloca</tt>' instruction
4305 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4306 runtime stack, returning a pointer of the appropriate type to the program.
4307 If "NumElements" is specified, it is the number of elements allocated,
4308 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4309 specified, the value result of the allocation is guaranteed to be aligned to
4310 at least that boundary. If not specified, or if zero, the target can choose
4311 to align the allocation on any convenient boundary compatible with the
4312 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4313
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4314<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4315
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4316<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4317<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4318 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4319 memory is automatically released when the function returns. The
4320 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4321 variables that must have an address available. When the function returns
4322 (either with the <tt><a href="#i_ret">ret</a></tt>
4323 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4324 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4326<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4327<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4328 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4329 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4330 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4331 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4332</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4333
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4334</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4335
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4336<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4337<h4>
4338 <a name="i_load">'<tt>load</tt>' Instruction</a>
4339</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4340
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4341<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4342
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4343<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4344<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4345 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4346 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4347 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4348</pre>
4349
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4350<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4351<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4352
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4353<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4354<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4355 from which to load. The pointer must point to
4356 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4357 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4358 number or order of execution of this <tt>load</tt> with other <a
4359 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4360
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4361<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4362 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]4363 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4364 alignment for the target. It is the responsibility of the code emitter to
4365 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4366 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4367 produce less efficient code. An alignment of 1 is always safe.</p>
4368
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4369<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4370 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4371 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4372 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4373 and code generator that this load is not expected to be reused in the cache.
4374 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4375 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4376
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4377<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4378<p>The location of memory pointed to is loaded. If the value being loaded is of
4379 scalar type then the number of bytes read does not exceed the minimum number
4380 of bytes needed to hold all bits of the type. For example, loading an
4381 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4382 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4383 is undefined if the value was not originally written using a store of the
4384 same type.</p>
4385
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4386<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4387<pre>
4388 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4389 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4390 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4391</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4392
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4393</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4394
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4395<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4396<h4>
4397 <a name="i_store">'<tt>store</tt>' Instruction</a>
4398</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4399
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4400<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4401
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4402<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4403<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4404 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4405 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4406</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4407
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4408<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4409<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4410
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4411<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4412<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4413 and an address at which to store it. The type of the
4414 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4415 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4416 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4417 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4418 order of execution of this <tt>store</tt> with other <a
4419 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4420
4421<p>The optional constant "align" argument specifies the alignment of the
4422 operation (that is, the alignment of the memory address). A value of 0 or an
4423 omitted "align" argument means that the operation has the preferential
4424 alignment for the target. It is the responsibility of the code emitter to
4425 ensure that the alignment information is correct. Overestimating the
4426 alignment results in an undefined behavior. Underestimating the alignment may
4427 produce less efficient code. An alignment of 1 is always safe.</p>
4428
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4429<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4430 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4431 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4432 instruction tells the optimizer and code generator that this load is
4433 not expected to be reused in the cache. The code generator may
4434 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4435 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4436
4437
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4438<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4439<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4440 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4441 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4442 does not exceed the minimum number of bytes needed to hold all bits of the
4443 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4444 writing a value of a type like <tt>i20</tt> with a size that is not an
4445 integral number of bytes, it is unspecified what happens to the extra bits
4446 that do not belong to the type, but they will typically be overwritten.</p>
4447
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4448<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4449<pre>
4450 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4451 store i32 3, i32* %ptr <i>; yields {void}</i>
4452 %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]4453</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4454
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4455</div>
4456
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4457<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4458<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4459 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4460</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4461
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4462<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4463
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4464<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4465<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4466 &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]4467 &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]4468</pre>
4469
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4470<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4471<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4472 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4473 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4474
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4475<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4476<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4477 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4478 elements of the aggregate object are indexed. The interpretation of each
4479 index is dependent on the type being indexed into. The first index always
4480 indexes the pointer value given as the first argument, the second index
4481 indexes a value of the type pointed to (not necessarily the value directly
4482 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4483 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4484 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4485 can never be pointers, since that would require loading the pointer before
4486 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4487
4488<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4489 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4490 integer <b>constants</b> are allowed. When indexing into an array, pointer
4491 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]4492 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4493
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4494<p>For example, let's consider a C code fragment and how it gets compiled to
4495 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4496
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4497<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4498struct RT {
4499 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4500 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4501 char C;
4502};
4503struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4504 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4505 double Y;
4506 struct RT Z;
4507};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4508
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4509int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4510 return &amp;s[1].Z.B[5][13];
4511}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4512</pre>
4513
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4514<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4515
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4516<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4517%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4518%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4519
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4520define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4521entry:
4522 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4523 ret i32* %reg
4524}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4525</pre>
4526
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4527<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4528<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]4529 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4530 }</tt>' type, a structure. The second index indexes into the third element
4531 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4532 i8 }</tt>' type, another structure. The third index indexes into the second
4533 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4534 array. The two dimensions of the array are subscripted into, yielding an
4535 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4536 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4537
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4538<p>Note that it is perfectly legal to index partially through a structure,
4539 returning a pointer to an inner element. Because of this, the LLVM code for
4540 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4541
4542<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4543 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4544 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4545 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4546 %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]4547 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4548 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4549 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4550 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4551</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4552
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4553<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4554 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4555 base pointer is not an <i>in bounds</i> address of an allocated object,
4556 or if any of the addresses that would be formed by successive addition of
4557 the offsets implied by the indices to the base address with infinitely
4558 precise arithmetic are not an <i>in bounds</i> address of that allocated
4559 object. The <i>in bounds</i> addresses for an allocated object are all
4560 the addresses that point into the object, plus the address one byte past
4561 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4562
4563<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4564 the base address with silently-wrapping two's complement arithmetic, and
4565 the result value of the <tt>getelementptr</tt> may be outside the object
4566 pointed to by the base pointer. The result value may not necessarily be
4567 used to access memory though, even if it happens to point into allocated
4568 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4569 section for more information.</p>
4570
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4571<p>The getelementptr instruction is often confusing. For some more insight into
4572 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4573
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4574<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4575<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4576 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4577 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4578 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4579 %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]4580 <i>; yields i8*:eptr</i>
4581 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4582 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4583 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4584</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4585
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4586</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4587
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4588</div>
4589
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4590<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4591<h3>
4592 <a name="convertops">Conversion Operations</a>
4593</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4594
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4595<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4596
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4597<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4598 which all take a single operand and a type. They perform various bit
4599 conversions on the operand.</p>
4600
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4601<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4602<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4603 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4604</h4>
4605
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4606<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4607
4608<h5>Syntax:</h5>
4609<pre>
4610 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4611</pre>
4612
4613<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4614<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4615 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4616
4617<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4618<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4619 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4620 of the same number of integers.
4621 The bit size of the <tt>value</tt> must be larger than
4622 the bit size of the destination type, <tt>ty2</tt>.
4623 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4624
4625<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4627 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4628 source size must be larger than the destination size, <tt>trunc</tt> cannot
4629 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4630
4631<h5>Example:</h5>
4632<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4633 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4634 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4635 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4636 %W = trunc &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i8&gt; <i>; yields &lt;i8 8, i8 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4637</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4638
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4639</div>
4640
4641<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4642<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4643 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4644</h4>
4645
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4646<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4647
4648<h5>Syntax:</h5>
4649<pre>
4650 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4651</pre>
4652
4653<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4654<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4655 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4656
4657
4658<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4659<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4660 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4661 of the same number of integers.
4662 The bit size of the <tt>value</tt> must be smaller than
4663 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4664 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4665
4666<h5>Semantics:</h5>
4667<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]4668 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4669
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4670<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]4671
4672<h5>Example:</h5>
4673<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4674 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4675 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4676 %Z = zext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4677</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4678
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4679</div>
4680
4681<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4682<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4683 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4684</h4>
4685
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4686<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4687
4688<h5>Syntax:</h5>
4689<pre>
4690 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4691</pre>
4692
4693<h5>Overview:</h5>
4694<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4695
4696<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4697<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4698 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4699 of the same number of integers.
4700 The bit size of the <tt>value</tt> must be smaller than
4701 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4702 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4703
4704<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4705<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4706 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4707 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4708
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4709<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]4710
4711<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4712<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4713 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4714 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4715 %Z = sext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4716</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4717
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4718</div>
4719
4720<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4721<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4722 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4723</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4724
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4725<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4726
4727<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4728<pre>
4729 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4730</pre>
4731
4732<h5>Overview:</h5>
4733<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4734 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4735
4736<h5>Arguments:</h5>
4737<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4738 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4739 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]4740 <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]4741 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4742
4743<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4744<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4745 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4746 <a href="#t_floating">floating point</a> type. If the value cannot fit
4747 within the destination type, <tt>ty2</tt>, then the results are
4748 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4749
4750<h5>Example:</h5>
4751<pre>
4752 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4753 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4754</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4755
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4756</div>
4757
4758<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4759<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4760 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4761</h4>
4762
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4763<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4764
4765<h5>Syntax:</h5>
4766<pre>
4767 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4768</pre>
4769
4770<h5>Overview:</h5>
4771<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]4772 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4773
4774<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4775<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4776 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4777 a <a href="#t_floating">floating point</a> type to cast it to. The source
4778 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4779
4780<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4781<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4782 <a href="#t_floating">floating point</a> type to a larger
4783 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4784 used to make a <i>no-op cast</i> because it always changes bits. Use
4785 <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]4786
4787<h5>Example:</h5>
4788<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]4789 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4790 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4791</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4792
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4793</div>
4794
4795<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4796<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4797 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4798</h4>
4799
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4800<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4801
4802<h5>Syntax:</h5>
4803<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4804 &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]4805</pre>
4806
4807<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4808<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4809 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4810
4811<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4812<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4813 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4814 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4815 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4816 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4817
4818<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4819<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4820 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4821 towards zero) unsigned integer value. If the value cannot fit
4822 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4823
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4824<h5>Example:</h5>
4825<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4826 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4827 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4828 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4829</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4830
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4831</div>
4832
4833<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4834<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4835 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4836</h4>
4837
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4838<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4839
4840<h5>Syntax:</h5>
4841<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4842 &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]4843</pre>
4844
4845<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4846<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4847 <a href="#t_floating">floating point</a> <tt>value</tt> to
4848 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4849
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4850<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4851<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4852 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4853 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4854 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4855 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4856
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4857<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4858<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4859 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4860 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4861 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4862
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4863<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4864<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4865 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4866 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4867 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4868</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4869
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4870</div>
4871
4872<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4873<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4874 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4875</h4>
4876
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4877<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4878
4879<h5>Syntax:</h5>
4880<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4881 &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]4882</pre>
4883
4884<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4885<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4886 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4887
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4888<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4889<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]4890 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4891 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4892 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4893 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4894
4895<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4896<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4897 integer quantity and converts it to the corresponding floating point
4898 value. If the value cannot fit in the floating point value, the results are
4899 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4900
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4901<h5>Example:</h5>
4902<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4903 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4904 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4905</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4906
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4907</div>
4908
4909<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4910<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4911 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4912</h4>
4913
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4914<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4915
4916<h5>Syntax:</h5>
4917<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4918 &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]4919</pre>
4920
4921<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4922<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4923 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4924
4925<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4926<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]4927 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4928 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4929 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4930 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4931
4932<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4933<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4934 quantity and converts it to the corresponding floating point value. If the
4935 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4936
4937<h5>Example:</h5>
4938<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4939 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4940 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4941</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4942
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4943</div>
4944
4945<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4946<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4947 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4948</h4>
4949
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4950<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4951
4952<h5>Syntax:</h5>
4953<pre>
4954 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4955</pre>
4956
4957<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4958<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4959 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4960
4961<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4962<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4963 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4964 <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]4965
4966<h5>Semantics:</h5>
4967<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4968 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4969 truncating or zero extending that value to the size of the integer type. If
4970 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4971 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4972 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4973 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4974
4975<h5>Example:</h5>
4976<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4977 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4978 %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]4979</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4980
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4981</div>
4982
4983<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4984<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4985 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4986</h4>
4987
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4988<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4989
4990<h5>Syntax:</h5>
4991<pre>
4992 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4993</pre>
4994
4995<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4996<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4997 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4998
4999<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5000<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5001 value to cast, and a type to cast it to, which must be a
5002 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5003
5004<h5>Semantics:</h5>
5005<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5006 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5007 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5008 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5009 than the size of a pointer then a zero extension is done. If they are the
5010 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5011
5012<h5>Example:</h5>
5013<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5014 %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]5015 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5016 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5017</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5018
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5019</div>
5020
5021<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5022<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5023 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5024</h4>
5025
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5026<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5027
5028<h5>Syntax:</h5>
5029<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5030 &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]5031</pre>
5032
5033<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5034<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5035 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5036
5037<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5038<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5039 non-aggregate first class value, and a type to cast it to, which must also be
5040 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5041 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5042 identical. If the source type is a pointer, the destination type must also be
5043 a pointer. This instruction supports bitwise conversion of vectors to
5044 integers and to vectors of other types (as long as they have the same
5045 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5046
5047<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5048<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5049 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5050 this conversion. The conversion is done as if the <tt>value</tt> had been
5051 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5052 be converted to other pointer types with this instruction. To convert
5053 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5054 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5055
5056<h5>Example:</h5>
5057<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5058 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5059 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5060 %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]5061</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5062
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5063</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5064
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5065</div>
5066
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5067<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5068<h3>
5069 <a name="otherops">Other Operations</a>
5070</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5071
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5072<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5073
5074<p>The instructions in this category are the "miscellaneous" instructions, which
5075 defy better classification.</p>
5076
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5077<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5078<h4>
5079 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5080</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5081
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5082<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5083
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5084<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5085<pre>
5086 &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]5087</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5088
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5089<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5090<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5091 boolean values based on comparison of its two integer, integer vector, or
5092 pointer operands.</p>
5093
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5094<h5>Arguments:</h5>
5095<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5096 the condition code indicating the kind of comparison to perform. It is not a
5097 value, just a keyword. The possible condition code are:</p>
5098
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5099<ol>
5100 <li><tt>eq</tt>: equal</li>
5101 <li><tt>ne</tt>: not equal </li>
5102 <li><tt>ugt</tt>: unsigned greater than</li>
5103 <li><tt>uge</tt>: unsigned greater or equal</li>
5104 <li><tt>ult</tt>: unsigned less than</li>
5105 <li><tt>ule</tt>: unsigned less or equal</li>
5106 <li><tt>sgt</tt>: signed greater than</li>
5107 <li><tt>sge</tt>: signed greater or equal</li>
5108 <li><tt>slt</tt>: signed less than</li>
5109 <li><tt>sle</tt>: signed less or equal</li>
5110</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5111
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5112<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5113 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5114 typed. They must also be identical types.</p>
5115
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5116<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5117<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5118 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5119 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]5120 result, as follows:</p>
5121
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5122<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5123 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5124 <tt>false</tt> otherwise. No sign interpretation is necessary or
5125 performed.</li>
5126
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5127 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5128 <tt>false</tt> otherwise. No sign interpretation is necessary or
5129 performed.</li>
5130
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5131 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5132 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5133
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5134 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5135 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5136 to <tt>op2</tt>.</li>
5137
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5138 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5139 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5140
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5141 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5142 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5143
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5144 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5145 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5146
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5147 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5148 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5149 to <tt>op2</tt>.</li>
5150
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5151 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5152 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5153
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5154 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5155 <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]5156</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5157
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5158<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5159 values are compared as if they were integers.</p>
5160
5161<p>If the operands are integer vectors, then they are compared element by
5162 element. The result is an <tt>i1</tt> vector with the same number of elements
5163 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5164
5165<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5166<pre>
5167 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5168 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5169 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5170 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5171 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5172 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5173</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5174
5175<p>Note that the code generator does not yet support vector types with
5176 the <tt>icmp</tt> instruction.</p>
5177
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5178</div>
5179
5180<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5181<h4>
5182 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5183</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5184
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5185<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5186
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5187<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5188<pre>
5189 &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]5190</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5191
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5192<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5193<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5194 values based on comparison of its operands.</p>
5195
5196<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]5197(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5198
5199<p>If the operands are floating point vectors, then the result type is a vector
5200 of boolean with the same number of elements as the operands being
5201 compared.</p>
5202
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5203<h5>Arguments:</h5>
5204<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5205 the condition code indicating the kind of comparison to perform. It is not a
5206 value, just a keyword. The possible condition code are:</p>
5207
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5208<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5209 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5210 <li><tt>oeq</tt>: ordered and equal</li>
5211 <li><tt>ogt</tt>: ordered and greater than </li>
5212 <li><tt>oge</tt>: ordered and greater than or equal</li>
5213 <li><tt>olt</tt>: ordered and less than </li>
5214 <li><tt>ole</tt>: ordered and less than or equal</li>
5215 <li><tt>one</tt>: ordered and not equal</li>
5216 <li><tt>ord</tt>: ordered (no nans)</li>
5217 <li><tt>ueq</tt>: unordered or equal</li>
5218 <li><tt>ugt</tt>: unordered or greater than </li>
5219 <li><tt>uge</tt>: unordered or greater than or equal</li>
5220 <li><tt>ult</tt>: unordered or less than </li>
5221 <li><tt>ule</tt>: unordered or less than or equal</li>
5222 <li><tt>une</tt>: unordered or not equal</li>
5223 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5224 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5225</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5227<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5228 <i>unordered</i> means that either operand may be a QNAN.</p>
5229
5230<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5231 a <a href="#t_floating">floating point</a> type or
5232 a <a href="#t_vector">vector</a> of floating point type. They must have
5233 identical types.</p>
5234
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5235<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5236<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5237 according to the condition code given as <tt>cond</tt>. If the operands are
5238 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5239 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5240 follows:</p>
5241
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5242<ol>
5243 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5244
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5245 <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]5246 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5247
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5248 <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]5249 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5250
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5251 <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]5252 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5253
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5254 <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]5255 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5256
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5257 <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]5258 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5259
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5260 <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]5261 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5262
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5263 <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]5264
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5265 <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]5266 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5267
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5268 <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]5269 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5270
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5271 <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]5272 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5273
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5274 <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]5275 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5276
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5277 <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]5278 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5279
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5280 <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]5281 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5282
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5283 <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]5284
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5285 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5286</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5287
5288<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5289<pre>
5290 &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]5291 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5292 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5293 &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]5294</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5295
5296<p>Note that the code generator does not yet support vector types with
5297 the <tt>fcmp</tt> instruction.</p>
5298
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5299</div>
5300
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5301<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5302<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5303 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5304</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5305
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5306<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5307
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5308<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5309<pre>
5310 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5311</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5312
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5313<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5314<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5315 SSA graph representing the function.</p>
5316
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5317<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5318<p>The type of the incoming values is specified with the first type field. After
5319 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5320 one pair for each predecessor basic block of the current block. Only values
5321 of <a href="#t_firstclass">first class</a> type may be used as the value
5322 arguments to the PHI node. Only labels may be used as the label
5323 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5324
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5325<p>There must be no non-phi instructions between the start of a basic block and
5326 the PHI instructions: i.e. PHI instructions must be first in a basic
5327 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5328
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5329<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5330 occur on the edge from the corresponding predecessor block to the current
5331 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5332 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5333
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5334<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5335<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5336 specified by the pair corresponding to the predecessor basic block that
5337 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5338
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5339<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5340<pre>
5341Loop: ; Infinite loop that counts from 0 on up...
5342 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5343 %nextindvar = add i32 %indvar, 1
5344 br label %Loop
5345</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5346
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5347</div>
5348
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5349<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5350<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5351 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5352</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5353
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5354<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5355
5356<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5357<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5358 &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>
5359
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5360 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5361</pre>
5362
5363<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5364<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5365 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5366
5367
5368<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5369<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5370 values indicating the condition, and two values of the
5371 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5372 vectors and the condition is a scalar, then entire vectors are selected, not
5373 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5374
5375<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5376<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5377 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5378
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5379<p>If the condition is a vector of i1, then the value arguments must be vectors
5380 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5381
5382<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5383<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5384 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5385</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5386
5387<p>Note that the code generator does not yet support conditions
5388 with vector type.</p>
5389
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5390</div>
5391
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5392<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5393<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5394 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5395</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5397<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5398
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5399<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5400<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5401 &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]5402</pre>
5403
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5404<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5405<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5406
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5407<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5408<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5409
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5410<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5411 <li>The optional "tail" marker indicates that the callee function does not
5412 access any allocas or varargs in the caller. Note that calls may be
5413 marked "tail" even if they do not occur before
5414 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5415 present, the function call is eligible for tail call optimization,
5416 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5417 optimized into a jump</a>. The code generator may optimize calls marked
5418 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5419 sibling call optimization</a> when the caller and callee have
5420 matching signatures, or 2) forced tail call optimization when the
5421 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5422 <ul>
5423 <li>Caller and callee both have the calling
5424 convention <tt>fastcc</tt>.</li>
5425 <li>The call is in tail position (ret immediately follows call and ret
5426 uses value of call or is void).</li>
5427 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5428 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5429 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5430 constraints are met.</a></li>
5431 </ul>
5432 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5433
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5434 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5435 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5436 defaults to using C calling conventions. The calling convention of the
5437 call must match the calling convention of the target function, or else the
5438 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5439
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5440 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5441 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5442 '<tt>inreg</tt>' attributes are valid here.</li>
5443
5444 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5445 type of the return value. Functions that return no value are marked
5446 <tt><a href="#t_void">void</a></tt>.</li>
5447
5448 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5449 being invoked. The argument types must match the types implied by this
5450 signature. This type can be omitted if the function is not varargs and if
5451 the function type does not return a pointer to a function.</li>
5452
5453 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5454 be invoked. In most cases, this is a direct function invocation, but
5455 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5456 to function value.</li>
5457
5458 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5459 signature argument types and parameter attributes. All arguments must be
5460 of <a href="#t_firstclass">first class</a> type. If the function
5461 signature indicates the function accepts a variable number of arguments,
5462 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5463
5464 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5465 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5466 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5467</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5469<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5470<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5471 a specified function, with its incoming arguments bound to the specified
5472 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5473 function, control flow continues with the instruction after the function
5474 call, and the return value of the function is bound to the result
5475 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5476
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5477<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5478<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5479 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5480 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5481 %X = tail call i32 @foo() <i>; yields i32</i>
5482 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5483 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5484
5485 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5486 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5487 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5488 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5489 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5490 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5491</pre>
5492
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5493<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5494standard C99 library as being the C99 library functions, and may perform
5495optimizations or generate code for them under that assumption. This is
5496something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5497freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5498
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5499</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5500
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5501<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5502<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5503 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5504</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5505
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5506<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5507
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5508<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5509<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5510 &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]5511</pre>
5512
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5513<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5514<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5515 the "variable argument" area of a function call. It is used to implement the
5516 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5517
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5518<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5519<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5520 argument. It returns a value of the specified argument type and increments
5521 the <tt>va_list</tt> to point to the next argument. The actual type
5522 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5523
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5524<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5525<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5526 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5527 to the next argument. For more information, see the variable argument
5528 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5529
5530<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]5531 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5532 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5533
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5534<p><tt>va_arg</tt> is an LLVM instruction instead of
5535 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5536 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5537
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5538<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5539<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5541<p>Note that the code generator does not yet fully support va_arg on many
5542 targets. Also, it does not currently support va_arg with aggregate types on
5543 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5544
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5545</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5546
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5547</div>
5548
5549</div>
5550
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5551<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5552<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5553<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5554
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5555<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5556
5557<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5558 well known names and semantics and are required to follow certain
5559 restrictions. Overall, these intrinsics represent an extension mechanism for
5560 the LLVM language that does not require changing all of the transformations
5561 in LLVM when adding to the language (or the bitcode reader/writer, the
5562 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5563
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5564<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5565 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5566 begin with this prefix. Intrinsic functions must always be external
5567 functions: you cannot define the body of intrinsic functions. Intrinsic
5568 functions may only be used in call or invoke instructions: it is illegal to
5569 take the address of an intrinsic function. Additionally, because intrinsic
5570 functions are part of the LLVM language, it is required if any are added that
5571 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5572
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5573<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5574 family of functions that perform the same operation but on different data
5575 types. Because LLVM can represent over 8 million different integer types,
5576 overloading is used commonly to allow an intrinsic function to operate on any
5577 integer type. One or more of the argument types or the result type can be
5578 overloaded to accept any integer type. Argument types may also be defined as
5579 exactly matching a previous argument's type or the result type. This allows
5580 an intrinsic function which accepts multiple arguments, but needs all of them
5581 to be of the same type, to only be overloaded with respect to a single
5582 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5583
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5584<p>Overloaded intrinsics will have the names of its overloaded argument types
5585 encoded into its function name, each preceded by a period. Only those types
5586 which are overloaded result in a name suffix. Arguments whose type is matched
5587 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5588 can take an integer of any width and returns an integer of exactly the same
5589 integer width. This leads to a family of functions such as
5590 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5591 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5592 suffix is required. Because the argument's type is matched against the return
5593 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5594
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5595<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5596 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5597
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5598<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5599<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5600 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5601</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5602
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5603<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5604
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5605<p>Variable argument support is defined in LLVM with
5606 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5607 intrinsic functions. These functions are related to the similarly named
5608 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5609
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5610<p>All of these functions operate on arguments that use a target-specific value
5611 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5612 not define what this type is, so all transformations should be prepared to
5613 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5614
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5615<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]5616 instruction and the variable argument handling intrinsic functions are
5617 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5618
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5619<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5620define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5621 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5622 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5623 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5624 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5625
5626 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5627 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5628
5629 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5630 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5631 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5632 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5633 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5634
5635 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5636 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5637 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5638}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5639
5640declare void @llvm.va_start(i8*)
5641declare void @llvm.va_copy(i8*, i8*)
5642declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5643</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5644
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5645<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5646<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5647 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5648</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5649
5650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5651<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5652
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5653<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5654<pre>
5655 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5656</pre>
5657
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5658<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5659<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5660 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]5661
5662<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5663<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]5664
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5665<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5666<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]5667 macro available in C. In a target-dependent way, it initializes
5668 the <tt>va_list</tt> element to which the argument points, so that the next
5669 call to <tt>va_arg</tt> will produce the first variable argument passed to
5670 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5671 need to know the last argument of the function as the compiler can figure
5672 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5673
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5674</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5675
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5676<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5677<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5678 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5679</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5680
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5681<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5682
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5683<h5>Syntax:</h5>
5684<pre>
5685 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5686</pre>
5687
5688<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5689<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5690 which has been initialized previously
5691 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5692 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5693
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5694<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5695<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]5696
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5697<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5698<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]5699 macro available in C. In a target-dependent way, it destroys
5700 the <tt>va_list</tt> element to which the argument points. Calls
5701 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5702 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5703 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5704
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5705</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5706
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5707<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5708<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5709 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5710</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5711
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5712<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5713
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5714<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5715<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5716 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5717</pre>
5718
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5719<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5720<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5721 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5722
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5723<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5724<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]5725 The second argument is a pointer to a <tt>va_list</tt> element to copy
5726 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5727
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5728<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5729<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]5730 macro available in C. In a target-dependent way, it copies the
5731 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5732 element. This intrinsic is necessary because
5733 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5734 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5735
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5736</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5737
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5738</div>
5739
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5740<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5741<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5742 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5743</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5744
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5745<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5746
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5747<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5748Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5750roots on the stack</a>, as well as garbage collector implementations that
5751require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5752barriers. Front-ends for type-safe garbage collected languages should generate
5753these intrinsics to make use of the LLVM garbage collectors. For more details,
5754see <a href="GarbageCollection.html">Accurate Garbage Collection with
5755LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5756
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5757<p>The garbage collection intrinsics only operate on objects in the generic
5758 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5759
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5760<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5761<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5762 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5763</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5764
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5765<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5766
5767<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5768<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5769 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5770</pre>
5771
5772<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5773<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]5774 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5775
5776<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5777<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5778 root pointer. The second pointer (which must be either a constant or a
5779 global value address) contains the meta-data to be associated with the
5780 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5781
5782<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5783<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]5784 location. At compile-time, the code generator generates information to allow
5785 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5786 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5787 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5788
5789</div>
5790
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5791<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5792<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5793 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5794</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5795
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5796<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5797
5798<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5799<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5800 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5801</pre>
5802
5803<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5804<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5805 locations, allowing garbage collector implementations that require read
5806 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5807
5808<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5809<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]5810 allocated from the garbage collector. The first object is a pointer to the
5811 start of the referenced object, if needed by the language runtime (otherwise
5812 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5813
5814<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5815<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5816 instruction, but may be replaced with substantially more complex code by the
5817 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5818 may only be used in a function which <a href="#gc">specifies a GC
5819 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5820
5821</div>
5822
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5823<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5824<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5825 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5826</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5827
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5828<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5829
5830<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5831<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5832 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5833</pre>
5834
5835<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5836<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5837 locations, allowing garbage collector implementations that require write
5838 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5839
5840<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5841<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]5842 object to store it to, and the third is the address of the field of Obj to
5843 store to. If the runtime does not require a pointer to the object, Obj may
5844 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5845
5846<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5847<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5848 instruction, but may be replaced with substantially more complex code by the
5849 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5850 may only be used in a function which <a href="#gc">specifies a GC
5851 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5852
5853</div>
5854
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5855</div>
5856
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5857<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5858<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5859 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5860</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5861
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5862<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5863
5864<p>These intrinsics are provided by LLVM to expose special features that may
5865 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5866
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5867<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5868<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5869 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5870</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5871
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5872<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5873
5874<h5>Syntax:</h5>
5875<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5876 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5877</pre>
5878
5879<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5880<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5881 target-specific value indicating the return address of the current function
5882 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5883
5884<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5885<p>The argument to this intrinsic indicates which function to return the address
5886 for. Zero indicates the calling function, one indicates its caller, etc.
5887 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5888
5889<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5890<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5891 indicating the return address of the specified call frame, or zero if it
5892 cannot be identified. The value returned by this intrinsic is likely to be
5893 incorrect or 0 for arguments other than zero, so it should only be used for
5894 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5895
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5896<p>Note that calling this intrinsic does not prevent function inlining or other
5897 aggressive transformations, so the value returned may not be that of the
5898 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5899
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5900</div>
5901
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5902<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5903<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5904 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5905</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5906
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5907<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5908
5909<h5>Syntax:</h5>
5910<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5911 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5912</pre>
5913
5914<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5915<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5916 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5917
5918<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5919<p>The argument to this intrinsic indicates which function to return the frame
5920 pointer for. Zero indicates the calling function, one indicates its caller,
5921 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5922
5923<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5924<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5925 indicating the frame address of the specified call frame, or zero if it
5926 cannot be identified. The value returned by this intrinsic is likely to be
5927 incorrect or 0 for arguments other than zero, so it should only be used for
5928 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5929
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5930<p>Note that calling this intrinsic does not prevent function inlining or other
5931 aggressive transformations, so the value returned may not be that of the
5932 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5933
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5934</div>
5935
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5936<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5937<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5938 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5939</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5940
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5941<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5942
5943<h5>Syntax:</h5>
5944<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5945 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5946</pre>
5947
5948<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5949<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5950 of the function stack, for use
5951 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5952 useful for implementing language features like scoped automatic variable
5953 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5954
5955<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5956<p>This intrinsic returns a opaque pointer value that can be passed
5957 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5958 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5959 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5960 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5961 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5962 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5963
5964</div>
5965
5966<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5967<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5968 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5969</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5970
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5971<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5972
5973<h5>Syntax:</h5>
5974<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5975 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +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.stackrestore</tt>' intrinsic is used to restore the state of
5980 the function stack to the state it was in when the
5981 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5982 executed. This is useful for implementing language features like scoped
5983 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5984
5985<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5986<p>See the description
5987 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5988
5989</div>
5990
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5991<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5992<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5993 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5994</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5995
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5996<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5997
5998<h5>Syntax:</h5>
5999<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6000 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6001</pre>
6002
6003<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6004<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6005 insert a prefetch instruction if supported; otherwise, it is a noop.
6006 Prefetches have no effect on the behavior of the program but can change its
6007 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6008
6009<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6010<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6011 specifier determining if the fetch should be for a read (0) or write (1),
6012 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6013 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6014 specifies whether the prefetch is performed on the data (1) or instruction (0)
6015 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6016 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6017
6018<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6019<p>This intrinsic does not modify the behavior of the program. In particular,
6020 prefetches cannot trap and do not produce a value. On targets that support
6021 this intrinsic, the prefetch can provide hints to the processor cache for
6022 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6023
6024</div>
6025
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6026<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6027<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6028 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6029</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6030
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6031<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6032
6033<h5>Syntax:</h5>
6034<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6035 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6036</pre>
6037
6038<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6039<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6040 Counter (PC) in a region of code to simulators and other tools. The method
6041 is target specific, but it is expected that the marker will use exported
6042 symbols to transmit the PC of the marker. The marker makes no guarantees
6043 that it will remain with any specific instruction after optimizations. It is
6044 possible that the presence of a marker will inhibit optimizations. The
6045 intended use is to be inserted after optimizations to allow correlations of
6046 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6047
6048<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6049<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6050
6051<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6052<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6053 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6054
6055</div>
6056
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6057<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6058<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6059 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6060</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6061
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6062<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6063
6064<h5>Syntax:</h5>
6065<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6066 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6067</pre>
6068
6069<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6070<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6071 counter register (or similar low latency, high accuracy clocks) on those
6072 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6073 should map to RPCC. As the backing counters overflow quickly (on the order
6074 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6075
6076<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6077<p>When directly supported, reading the cycle counter should not modify any
6078 memory. Implementations are allowed to either return a application specific
6079 value or a system wide value. On backends without support, this is lowered
6080 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6081
6082</div>
6083
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6084</div>
6085
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6086<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6087<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6088 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6089</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6090
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6091<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6092
6093<p>LLVM provides intrinsics for a few important standard C library functions.
6094 These intrinsics allow source-language front-ends to pass information about
6095 the alignment of the pointer arguments to the code generator, providing
6096 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6097
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6098<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6099<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6100 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6101</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6102
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6103<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6104
6105<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6106<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6107 integer bit width and for different address spaces. Not all targets support
6108 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6109
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6110<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6111 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6112 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6113 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6114 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6115</pre>
6116
6117<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6118<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6119 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6120
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6121<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6122 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6123 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6124
6125<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6126
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6127<p>The first argument is a pointer to the destination, the second is a pointer
6128 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6129 number of bytes to copy, the fourth argument is the alignment of the
6130 source and destination locations, and the fifth is a boolean indicating a
6131 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6132
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6133<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]6134 then the caller guarantees that both the source and destination pointers are
6135 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6136
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6137<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6138 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6139 The detailed access behavior is not very cleanly specified and it is unwise
6140 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6141
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6142<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6143
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6144<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6145 source location to the destination location, which are not allowed to
6146 overlap. It copies "len" bytes of memory over. If the argument is known to
6147 be aligned to some boundary, this can be specified as the fourth argument,
6148 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6149
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6150</div>
6151
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6152<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6153<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6154 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6155</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6156
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6157<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6158
6159<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6160<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6161 width and for different address space. Not all targets support all bit
6162 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6163
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6164<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6165 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6166 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6167 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6168 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6169</pre>
6170
6171<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6172<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6173 source location to the destination location. It is similar to the
6174 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6175 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6176
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6177<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6178 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6179 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6180
6181<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6182
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6183<p>The first argument is a pointer to the destination, the second is a pointer
6184 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6185 number of bytes to copy, the fourth argument is the alignment of the
6186 source and destination locations, and the fifth is a boolean indicating a
6187 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6188
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6189<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]6190 then the caller guarantees that the source and destination pointers are
6191 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6192
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6193<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6194 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6195 The detailed access behavior is not very cleanly specified and it is unwise
6196 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6197
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6198<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6199
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6200<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6201 source location to the destination location, which may overlap. It copies
6202 "len" bytes of memory over. If the argument is known to be aligned to some
6203 boundary, this can be specified as the fourth argument, otherwise it should
6204 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6205
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6206</div>
6207
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6208<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6209<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6210 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6211</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6212
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6213<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6214
6215<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6216<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6217 width and for different address spaces. However, not all targets support all
6218 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6219
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6220<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6221 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6222 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6223 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6224 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6225</pre>
6226
6227<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6228<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6229 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6230
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6231<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6232 intrinsic does not return a value and takes extra alignment/volatile
6233 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6234
6235<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6236<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6237 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6238 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6239 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6240
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6241<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]6242 then the caller guarantees that the destination pointer is aligned to that
6243 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6244
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6245<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6246 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6247 The detailed access behavior is not very cleanly specified and it is unwise
6248 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6249
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6250<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6251<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6252 at the destination location. If the argument is known to be aligned to some
6253 boundary, this can be specified as the fourth argument, otherwise it should
6254 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6255
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6256</div>
6257
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6258<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6259<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6260 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6261</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6262
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6263<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6264
6265<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6266<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6267 floating point or vector of floating point type. Not all targets support all
6268 types however.</p>
6269
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6270<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6271 declare float @llvm.sqrt.f32(float %Val)
6272 declare double @llvm.sqrt.f64(double %Val)
6273 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6274 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6275 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6276</pre>
6277
6278<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6279<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6280 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6281 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6282 behavior for negative numbers other than -0.0 (which allows for better
6283 optimization, because there is no need to worry about errno being
6284 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]6285
6286<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6287<p>The argument and return value are floating point numbers of the same
6288 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6289
6290<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6291<p>This function returns the sqrt of the specified operand if it is a
6292 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6293
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6294</div>
6295
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6296<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6297<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6298 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6299</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6300
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6301<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6302
6303<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6304<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6305 floating point or vector of floating point type. Not all targets support all
6306 types however.</p>
6307
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6308<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6309 declare float @llvm.powi.f32(float %Val, i32 %power)
6310 declare double @llvm.powi.f64(double %Val, i32 %power)
6311 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6312 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6313 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6314</pre>
6315
6316<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6317<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6318 specified (positive or negative) power. The order of evaluation of
6319 multiplications is not defined. When a vector of floating point type is
6320 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6321
6322<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6323<p>The second argument is an integer power, and the first is a value to raise to
6324 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6325
6326<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6327<p>This function returns the first value raised to the second power with an
6328 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6329
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6330</div>
6331
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6332<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6333<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6334 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6335</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6336
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6337<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6338
6339<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6340<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6341 floating point or vector of floating point type. Not all targets support all
6342 types however.</p>
6343
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6344<pre>
6345 declare float @llvm.sin.f32(float %Val)
6346 declare double @llvm.sin.f64(double %Val)
6347 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6348 declare fp128 @llvm.sin.f128(fp128 %Val)
6349 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6350</pre>
6351
6352<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6353<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6354
6355<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6356<p>The argument and return value are floating point numbers of the same
6357 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6358
6359<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6360<p>This function returns the sine of the specified operand, returning the same
6361 values as the libm <tt>sin</tt> functions would, and handles error conditions
6362 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6363
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6364</div>
6365
6366<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6367<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6368 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6369</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6370
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6371<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6372
6373<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6374<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6375 floating point or vector of floating point type. Not all targets support all
6376 types however.</p>
6377
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6378<pre>
6379 declare float @llvm.cos.f32(float %Val)
6380 declare double @llvm.cos.f64(double %Val)
6381 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6382 declare fp128 @llvm.cos.f128(fp128 %Val)
6383 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6384</pre>
6385
6386<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6387<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6388
6389<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6390<p>The argument and return value are floating point numbers of the same
6391 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6392
6393<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6394<p>This function returns the cosine of the specified operand, returning the same
6395 values as the libm <tt>cos</tt> functions would, and handles error conditions
6396 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6397
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6398</div>
6399
6400<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6401<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6402 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6403</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6404
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6405<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6406
6407<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6408<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6409 floating point or vector of floating point type. Not all targets support all
6410 types however.</p>
6411
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6412<pre>
6413 declare float @llvm.pow.f32(float %Val, float %Power)
6414 declare double @llvm.pow.f64(double %Val, double %Power)
6415 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6416 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6417 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6418</pre>
6419
6420<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6421<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6422 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6423
6424<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6425<p>The second argument is a floating point power, and the first is a value to
6426 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6427
6428<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6429<p>This function returns the first value raised to the second power, returning
6430 the same values as the libm <tt>pow</tt> functions would, and handles error
6431 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6432
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6433</div>
6434
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6435</div>
6436
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6437<!-- _______________________________________________________________________ -->
6438<h4>
6439 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6440</h4>
6441
6442<div>
6443
6444<h5>Syntax:</h5>
6445<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6446 floating point or vector of floating point type. Not all targets support all
6447 types however.</p>
6448
6449<pre>
6450 declare float @llvm.exp.f32(float %Val)
6451 declare double @llvm.exp.f64(double %Val)
6452 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6453 declare fp128 @llvm.exp.f128(fp128 %Val)
6454 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6455</pre>
6456
6457<h5>Overview:</h5>
6458<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6459
6460<h5>Arguments:</h5>
6461<p>The argument and return value are floating point numbers of the same
6462 type.</p>
6463
6464<h5>Semantics:</h5>
6465<p>This function returns the same values as the libm <tt>exp</tt> functions
6466 would, and handles error conditions in the same way.</p>
6467
6468</div>
6469
6470<!-- _______________________________________________________________________ -->
6471<h4>
6472 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6473</h4>
6474
6475<div>
6476
6477<h5>Syntax:</h5>
6478<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6479 floating point or vector of floating point type. Not all targets support all
6480 types however.</p>
6481
6482<pre>
6483 declare float @llvm.log.f32(float %Val)
6484 declare double @llvm.log.f64(double %Val)
6485 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6486 declare fp128 @llvm.log.f128(fp128 %Val)
6487 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6488</pre>
6489
6490<h5>Overview:</h5>
6491<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6492
6493<h5>Arguments:</h5>
6494<p>The argument and return value are floating point numbers of the same
6495 type.</p>
6496
6497<h5>Semantics:</h5>
6498<p>This function returns the same values as the libm <tt>log</tt> functions
6499 would, and handles error conditions in the same way.</p>
6500
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6501<h4>
6502 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6503</h4>
6504
6505<div>
6506
6507<h5>Syntax:</h5>
6508<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6509 floating point or vector of floating point type. Not all targets support all
6510 types however.</p>
6511
6512<pre>
6513 declare float @llvm.fma.f32(float %a, float %b, float %c)
6514 declare double @llvm.fma.f64(double %a, double %b, double %c)
6515 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6516 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6517 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6518</pre>
6519
6520<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]6521<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6522 operation.</p>
6523
6524<h5>Arguments:</h5>
6525<p>The argument and return value are floating point numbers of the same
6526 type.</p>
6527
6528<h5>Semantics:</h5>
6529<p>This function returns the same values as the libm <tt>fma</tt> functions
6530 would.</p>
6531
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6532</div>
6533
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6534<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6535<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6536 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6537</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6538
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6539<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6540
6541<p>LLVM provides intrinsics for a few important bit manipulation operations.
6542 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6543
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6544<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6545<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6546 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6547</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6548
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6549<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6550
6551<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6552<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6553 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6554
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6555<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6556 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6557 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6558 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6559</pre>
6560
6561<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6562<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6563 values with an even number of bytes (positive multiple of 16 bits). These
6564 are useful for performing operations on data that is not in the target's
6565 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6566
6567<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6568<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6569 and low byte of the input i16 swapped. Similarly,
6570 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6571 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6572 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6573 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6574 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6575 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6576
6577</div>
6578
6579<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6580<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6581 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6582</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6583
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6584<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6585
6586<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6587<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6588 width, or on any vector with integer elements. Not all targets support all
6589 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6590
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6591<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6592 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6593 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6594 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6595 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6596 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6597 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6598</pre>
6599
6600<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6601<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6602 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6603
6604<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6605<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6606 integer type, or a vector with integer elements.
6607 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6608
6609<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6610<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6611 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6612
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6613</div>
6614
6615<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6616<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6617 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6618</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6619
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6620<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6621
6622<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6623<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6624 integer bit width, or any vector whose elements are integers. Not all
6625 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6626
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6627<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6628 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6629 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6630 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6631 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6632 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6633 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6634</pre>
6635
6636<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6637<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6638 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6639
6640<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6641<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6642 integer type, or any vector type with integer element type.
6643 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6644
6645<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6646<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6647 zeros in a variable, or within each element of the vector if the operation
6648 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6649 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6650
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6651</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6652
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6653<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6654<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6655 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6656</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6657
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6658<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6659
6660<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6661<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6662 integer bit width, or any vector of integer elements. Not all targets
6663 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6664
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6665<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6666 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6667 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6668 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6669 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6670 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6671 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6672</pre>
6673
6674<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6675<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6676 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6677
6678<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6679<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6680 integer type, or a vectory with integer element type.. The return type
6681 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6682
6683<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6684<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6685 zeros in a variable, or within each element of a vector.
6686 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6687 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6688
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6689</div>
6690
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6691</div>
6692
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6693<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6694<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6695 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6696</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6697
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6698<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6699
6700<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6701
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6702<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6703<h4>
6704 <a name="int_sadd_overflow">
6705 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6706 </a>
6707</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6708
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6709<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6710
6711<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6712<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]6713 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6714
6715<pre>
6716 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6717 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6718 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6719</pre>
6720
6721<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6722<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6723 a signed addition of the two arguments, and indicate whether an overflow
6724 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6725
6726<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6727<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]6728 be of integer types of any bit width, but they must have the same bit
6729 width. The second element of the result structure must be of
6730 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6731 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6732
6733<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6734<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6735 a signed addition of the two variables. They return a structure &mdash; the
6736 first element of which is the signed summation, and the second element of
6737 which is a bit specifying if the signed summation resulted in an
6738 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6739
6740<h5>Examples:</h5>
6741<pre>
6742 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6743 %sum = extractvalue {i32, i1} %res, 0
6744 %obit = extractvalue {i32, i1} %res, 1
6745 br i1 %obit, label %overflow, label %normal
6746</pre>
6747
6748</div>
6749
6750<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6751<h4>
6752 <a name="int_uadd_overflow">
6753 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6754 </a>
6755</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6756
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6757<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6758
6759<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6760<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]6761 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6762
6763<pre>
6764 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6765 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6766 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6767</pre>
6768
6769<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6770<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6771 an unsigned addition of the two arguments, and indicate whether a carry
6772 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6773
6774<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6775<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]6776 be of integer types of any bit width, but they must have the same bit
6777 width. The second element of the result structure must be of
6778 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6779 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6780
6781<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6782<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6783 an unsigned addition of the two arguments. They return a structure &mdash;
6784 the first element of which is the sum, and the second element of which is a
6785 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6786
6787<h5>Examples:</h5>
6788<pre>
6789 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6790 %sum = extractvalue {i32, i1} %res, 0
6791 %obit = extractvalue {i32, i1} %res, 1
6792 br i1 %obit, label %carry, label %normal
6793</pre>
6794
6795</div>
6796
6797<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6798<h4>
6799 <a name="int_ssub_overflow">
6800 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6801 </a>
6802</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6803
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6804<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6805
6806<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6807<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]6808 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6809
6810<pre>
6811 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6812 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6813 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6814</pre>
6815
6816<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6817<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6818 a signed subtraction of the two arguments, and indicate whether an overflow
6819 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6820
6821<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6822<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]6823 be of integer types of any bit width, but they must have the same bit
6824 width. The second element of the result structure must be of
6825 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6826 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6827
6828<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6829<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6830 a signed subtraction of the two arguments. They return a structure &mdash;
6831 the first element of which is the subtraction, and the second element of
6832 which is a bit specifying if the signed subtraction resulted in an
6833 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6834
6835<h5>Examples:</h5>
6836<pre>
6837 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6838 %sum = extractvalue {i32, i1} %res, 0
6839 %obit = extractvalue {i32, i1} %res, 1
6840 br i1 %obit, label %overflow, label %normal
6841</pre>
6842
6843</div>
6844
6845<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6846<h4>
6847 <a name="int_usub_overflow">
6848 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6849 </a>
6850</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6851
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6852<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6853
6854<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6855<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]6856 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6857
6858<pre>
6859 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6860 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6861 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6862</pre>
6863
6864<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6865<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6866 an unsigned subtraction of the two arguments, and indicate whether an
6867 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6868
6869<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6870<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]6871 be of integer types of any bit width, but they must have the same bit
6872 width. The second element of the result structure must be of
6873 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6874 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6875
6876<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6877<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6878 an unsigned subtraction of the two arguments. They return a structure &mdash;
6879 the first element of which is the subtraction, and the second element of
6880 which is a bit specifying if the unsigned subtraction resulted in an
6881 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6882
6883<h5>Examples:</h5>
6884<pre>
6885 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6886 %sum = extractvalue {i32, i1} %res, 0
6887 %obit = extractvalue {i32, i1} %res, 1
6888 br i1 %obit, label %overflow, label %normal
6889</pre>
6890
6891</div>
6892
6893<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6894<h4>
6895 <a name="int_smul_overflow">
6896 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6897 </a>
6898</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6899
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6900<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6901
6902<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6903<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]6904 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6905
6906<pre>
6907 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6908 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6909 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6910</pre>
6911
6912<h5>Overview:</h5>
6913
6914<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6915 a signed multiplication of the two arguments, and indicate whether an
6916 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6917
6918<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6919<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]6920 be of integer types of any bit width, but they must have the same bit
6921 width. The second element of the result structure must be of
6922 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6923 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6924
6925<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6926<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6927 a signed multiplication of the two arguments. They return a structure &mdash;
6928 the first element of which is the multiplication, and the second element of
6929 which is a bit specifying if the signed multiplication resulted in an
6930 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6931
6932<h5>Examples:</h5>
6933<pre>
6934 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6935 %sum = extractvalue {i32, i1} %res, 0
6936 %obit = extractvalue {i32, i1} %res, 1
6937 br i1 %obit, label %overflow, label %normal
6938</pre>
6939
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6940</div>
6941
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6942<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6943<h4>
6944 <a name="int_umul_overflow">
6945 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
6946 </a>
6947</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6948
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6949<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6950
6951<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6952<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]6953 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6954
6955<pre>
6956 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6957 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6958 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6959</pre>
6960
6961<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6962<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6963 a unsigned multiplication of the two arguments, and indicate whether an
6964 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6965
6966<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6967<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]6968 be of integer types of any bit width, but they must have the same bit
6969 width. The second element of the result structure must be of
6970 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6971 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6972
6973<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6974<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6975 an unsigned multiplication of the two arguments. They return a structure
6976 &mdash; the first element of which is the multiplication, and the second
6977 element of which is a bit specifying if the unsigned multiplication resulted
6978 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6979
6980<h5>Examples:</h5>
6981<pre>
6982 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6983 %sum = extractvalue {i32, i1} %res, 0
6984 %obit = extractvalue {i32, i1} %res, 1
6985 br i1 %obit, label %overflow, label %normal
6986</pre>
6987
6988</div>
6989
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6990</div>
6991
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6992<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6993<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6994 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6995</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6996
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6997<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6998
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6999<p>Half precision floating point is a storage-only format. This means that it is
7000 a dense encoding (in memory) but does not support computation in the
7001 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7002
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7003<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7004 value as an i16, then convert it to float with <a
7005 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7006 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7007 double etc). To store the value back to memory, it is first converted to
7008 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7009 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7010 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7011
7012<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7013<h4>
7014 <a name="int_convert_to_fp16">
7015 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7016 </a>
7017</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7018
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7019<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7020
7021<h5>Syntax:</h5>
7022<pre>
7023 declare i16 @llvm.convert.to.fp16(f32 %a)
7024</pre>
7025
7026<h5>Overview:</h5>
7027<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7028 a conversion from single precision floating point format to half precision
7029 floating point format.</p>
7030
7031<h5>Arguments:</h5>
7032<p>The intrinsic function contains single argument - the value to be
7033 converted.</p>
7034
7035<h5>Semantics:</h5>
7036<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7037 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7038 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7039 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7040
7041<h5>Examples:</h5>
7042<pre>
7043 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7044 store i16 %res, i16* @x, align 2
7045</pre>
7046
7047</div>
7048
7049<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7050<h4>
7051 <a name="int_convert_from_fp16">
7052 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7053 </a>
7054</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7055
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7056<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7057
7058<h5>Syntax:</h5>
7059<pre>
7060 declare f32 @llvm.convert.from.fp16(i16 %a)
7061</pre>
7062
7063<h5>Overview:</h5>
7064<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7065 a conversion from half precision floating point format to single precision
7066 floating point format.</p>
7067
7068<h5>Arguments:</h5>
7069<p>The intrinsic function contains single argument - the value to be
7070 converted.</p>
7071
7072<h5>Semantics:</h5>
7073<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7074 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7075 precision floating point format. The input half-float value is represented by
7076 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7077
7078<h5>Examples:</h5>
7079<pre>
7080 %a = load i16* @x, align 2
7081 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7082</pre>
7083
7084</div>
7085
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7086</div>
7087
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7088<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7089<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7090 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7091</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7092
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7093<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7094
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7095<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7096 prefix), are described in
7097 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7098 Level Debugging</a> document.</p>
7099
7100</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7101
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7102<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7103<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7104 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7105</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7106
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7107<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7108
7109<p>The LLVM exception handling intrinsics (which all start with
7110 <tt>llvm.eh.</tt> prefix), are described in
7111 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7112 Handling</a> document.</p>
7113
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7114</div>
7115
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7116<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7117<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7118 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7119</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7120
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7121<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7122
7123<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7124 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7125 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7126 function pointer lacking the nest parameter - the caller does not need to
7127 provide a value for it. Instead, the value to use is stored in advance in a
7128 "trampoline", a block of memory usually allocated on the stack, which also
7129 contains code to splice the nest value into the argument list. This is used
7130 to implement the GCC nested function address extension.</p>
7131
7132<p>For example, if the function is
7133 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7134 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7135 follows:</p>
7136
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7137<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7138 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7139 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7140 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7141 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7142</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7143
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7144<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7145 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7146
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7147<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7148<h4>
7149 <a name="int_it">
7150 '<tt>llvm.init.trampoline</tt>' Intrinsic
7151 </a>
7152</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7153
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7154<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7155
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7156<h5>Syntax:</h5>
7157<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7158 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]7159</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7160
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7161<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7162<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7163 function pointer suitable for executing it.</p>
7164
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7165<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7166<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7167 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7168 sufficiently aligned block of memory; this memory is written to by the
7169 intrinsic. Note that the size and the alignment are target-specific - LLVM
7170 currently provides no portable way of determining them, so a front-end that
7171 generates this intrinsic needs to have some target-specific knowledge.
7172 The <tt>func</tt> argument must hold a function bitcast to
7173 an <tt>i8*</tt>.</p>
7174
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7175<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7176<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7177 dependent code, turning it into a function. A pointer to this function is
7178 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7179 function pointer type</a> before being called. The new function's signature
7180 is the same as that of <tt>func</tt> with any arguments marked with
7181 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7182 is allowed, and it must be of pointer type. Calling the new function is
7183 equivalent to calling <tt>func</tt> with the same argument list, but
7184 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7185 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7186 by <tt>tramp</tt> is modified, then the effect of any later call to the
7187 returned function pointer is undefined.</p>
7188
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7189</div>
7190
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7191</div>
7192
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7193<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7194<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7195 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7196</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7197
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7198<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7199
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7200<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7201 hardware constructs for atomic operations and memory synchronization. This
7202 provides an interface to the hardware, not an interface to the programmer. It
7203 is aimed at a low enough level to allow any programming models or APIs
7204 (Application Programming Interfaces) which need atomic behaviors to map
7205 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7206 hardware provides a "universal IR" for source languages, it also provides a
7207 starting point for developing a "universal" atomic operation and
7208 synchronization IR.</p>
7209
7210<p>These do <em>not</em> form an API such as high-level threading libraries,
7211 software transaction memory systems, atomic primitives, and intrinsic
7212 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7213 application libraries. The hardware interface provided by LLVM should allow
7214 a clean implementation of all of these APIs and parallel programming models.
7215 No one model or paradigm should be selected above others unless the hardware
7216 itself ubiquitously does so.</p>
7217
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7218<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7219<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7220 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7221</h4>
7222
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7223<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7224<h5>Syntax:</h5>
7225<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7226 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]7227</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7228
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7229<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7230<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7231 specific pairs of memory access types.</p>
7232
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7233<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7234<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7235 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7236 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7237 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7238
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7239<ul>
7240 <li><tt>ll</tt>: load-load barrier</li>
7241 <li><tt>ls</tt>: load-store barrier</li>
7242 <li><tt>sl</tt>: store-load barrier</li>
7243 <li><tt>ss</tt>: store-store barrier</li>
7244 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7245</ul>
7246
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7247<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7248<p>This intrinsic causes the system to enforce some ordering constraints upon
7249 the loads and stores of the program. This barrier does not
7250 indicate <em>when</em> any events will occur, it only enforces
7251 an <em>order</em> in which they occur. For any of the specified pairs of load
7252 and store operations (f.ex. load-load, or store-load), all of the first
7253 operations preceding the barrier will complete before any of the second
7254 operations succeeding the barrier begin. Specifically the semantics for each
7255 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7256
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7257<ul>
7258 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7259 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7260 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7261 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7262 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7263 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7264 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7265 load after the barrier begins.</li>
7266</ul>
7267
7268<p>These semantics are applied with a logical "and" behavior when more than one
7269 is enabled in a single memory barrier intrinsic.</p>
7270
7271<p>Backends may implement stronger barriers than those requested when they do
7272 not support as fine grained a barrier as requested. Some architectures do
7273 not need all types of barriers and on such architectures, these become
7274 noops.</p>
7275
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7276<h5>Example:</h5>
7277<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7278%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7279%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7280 store i32 4, %ptr
7281
7282%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7283 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7284 <i>; guarantee the above finishes</i>
7285 store i32 8, %ptr <i>; before this begins</i>
7286</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7287
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7288</div>
7289
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7290<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7291<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7292 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7293</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7294
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7295<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7296
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7297<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7298<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7299 any integer bit width and for different address spaces. Not all targets
7300 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7301
7302<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7303 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7304 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7305 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7306 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]7307</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7308
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7309<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7310<p>This loads a value in memory and compares it to a given value. If they are
7311 equal, it stores a new value into the memory.</p>
7312
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7313<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7314<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7315 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7316 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7317 this integer type. While any bit width integer may be used, targets may only
7318 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7319
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7320<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7321<p>This entire intrinsic must be executed atomically. It first loads the value
7322 in memory pointed to by <tt>ptr</tt> and compares it with the
7323 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7324 memory. The loaded value is yielded in all cases. This provides the
7325 equivalent of an atomic compare-and-swap operation within the SSA
7326 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7327
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7328<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7329<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7330%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7331%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7332 store i32 4, %ptr
7333
7334%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7335%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7336 <i>; yields {i32}:result1 = 4</i>
7337%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7338%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7339
7340%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7341%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7342 <i>; yields {i32}:result2 = 8</i>
7343%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7344
7345%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7346</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7347
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7348</div>
7349
7350<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7351<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7352 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7353</h4>
7354
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7355<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7356<h5>Syntax:</h5>
7357
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7358<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7359 integer bit width. Not all targets support all bit widths however.</p>
7360
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7361<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7362 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7363 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7364 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7365 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]7366</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7367
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7368<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7369<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7370 the value from memory. It then stores the value in <tt>val</tt> in the memory
7371 at <tt>ptr</tt>.</p>
7372
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7373<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7374<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7375 the <tt>val</tt> argument and the result must be integers of the same bit
7376 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7377 integer type. The targets may only lower integer representations they
7378 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7379
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7380<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7381<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7382 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7383 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7384
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7385<h5>Examples:</h5>
7386<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7387%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7388%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7389 store i32 4, %ptr
7390
7391%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7392%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7393 <i>; yields {i32}:result1 = 4</i>
7394%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7395%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7396
7397%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7398%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7399 <i>; yields {i32}:result2 = 8</i>
7400
7401%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7402%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7403</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7404
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7405</div>
7406
7407<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7408<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7409 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7410</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7411
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7412<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7413
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7414<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7415<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7416 any integer bit width. Not all targets support all bit widths however.</p>
7417
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7418<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7419 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7420 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7421 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7422 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]7423</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7424
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7425<h5>Overview:</h5>
7426<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7427 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7428
7429<h5>Arguments:</h5>
7430<p>The intrinsic takes two arguments, the first a pointer to an integer value
7431 and the second an integer value. The result is also an integer value. These
7432 integer types can have any bit width, but they must all have the same bit
7433 width. The targets may only lower integer representations they support.</p>
7434
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7435<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7436<p>This intrinsic does a series of operations atomically. It first loads the
7437 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7438 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]7439
7440<h5>Examples:</h5>
7441<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7442%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7443%ptr = bitcast i8* %mallocP to i32*
7444 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7445%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7446 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7447%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7448 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7449%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7450 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7451%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7452</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7453
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7454</div>
7455
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7456<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7457<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7458 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7459</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7460
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7461<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7462
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7463<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7464<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7465 any integer bit width and for different address spaces. Not all targets
7466 support all bit widths however.</p>
7467
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7468<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7469 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7470 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7471 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7472 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]7473</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7474
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7475<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7476<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7477 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7478
7479<h5>Arguments:</h5>
7480<p>The intrinsic takes two arguments, the first a pointer to an integer value
7481 and the second an integer value. The result is also an integer value. These
7482 integer types can have any bit width, but they must all have the same bit
7483 width. The targets may only lower integer representations they support.</p>
7484
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7485<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7486<p>This intrinsic does a series of operations atomically. It first loads the
7487 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7488 result to <tt>ptr</tt>. It yields the original value stored
7489 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7490
7491<h5>Examples:</h5>
7492<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7493%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7494%ptr = bitcast i8* %mallocP to i32*
7495 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7496%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7497 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7498%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7499 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7500%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7501 <i>; yields {i32}:result3 = 2</i>
7502%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7503</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7504
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7505</div>
7506
7507<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7508<h4>
7509 <a name="int_atomic_load_and">
7510 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7511 </a>
7512 <br>
7513 <a name="int_atomic_load_nand">
7514 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7515 </a>
7516 <br>
7517 <a name="int_atomic_load_or">
7518 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7519 </a>
7520 <br>
7521 <a name="int_atomic_load_xor">
7522 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7523 </a>
7524</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7525
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7526<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7527
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7528<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7529<p>These are overloaded intrinsics. You can
7530 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7531 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7532 bit width and for different address spaces. Not all targets support all bit
7533 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7534
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7535<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7536 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7537 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7538 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7539 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]7540</pre>
7541
7542<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7543 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7544 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7545 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7546 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]7547</pre>
7548
7549<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7550 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7551 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7552 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7553 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]7554</pre>
7555
7556<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7557 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7558 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7559 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7560 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]7561</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7562
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7563<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7564<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7565 the value stored in memory at <tt>ptr</tt>. It yields the original value
7566 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7567
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7568<h5>Arguments:</h5>
7569<p>These intrinsics take two arguments, the first a pointer to an integer value
7570 and the second an integer value. The result is also an integer value. These
7571 integer types can have any bit width, but they must all have the same bit
7572 width. The targets may only lower integer representations they support.</p>
7573
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7574<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7575<p>These intrinsics does a series of operations atomically. They first load the
7576 value stored at <tt>ptr</tt>. They then do the bitwise
7577 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7578 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7579
7580<h5>Examples:</h5>
7581<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7582%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7583%ptr = bitcast i8* %mallocP to i32*
7584 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7585%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7586 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7587%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7588 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7589%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7590 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7591%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7592 <i>; yields {i32}:result3 = FF</i>
7593%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7594</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7595
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7596</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7597
7598<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7599<h4>
7600 <a name="int_atomic_load_max">
7601 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7602 </a>
7603 <br>
7604 <a name="int_atomic_load_min">
7605 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7606 </a>
7607 <br>
7608 <a name="int_atomic_load_umax">
7609 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7610 </a>
7611 <br>
7612 <a name="int_atomic_load_umin">
7613 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7614 </a>
7615</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7616
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7617<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7618
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7619<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7620<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7621 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7622 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7623 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7624
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7625<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7626 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7627 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7628 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7629 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]7630</pre>
7631
7632<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7633 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7634 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7635 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7636 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]7637</pre>
7638
7639<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7640 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7641 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7642 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7643 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]7644</pre>
7645
7646<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7647 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7648 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7649 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7650 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]7651</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7652
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7653<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7654<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7655 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7656 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7657
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7658<h5>Arguments:</h5>
7659<p>These intrinsics take two arguments, the first a pointer to an integer value
7660 and the second an integer value. The result is also an integer value. These
7661 integer types can have any bit width, but they must all have the same bit
7662 width. The targets may only lower integer representations they support.</p>
7663
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7664<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7665<p>These intrinsics does a series of operations atomically. They first load the
7666 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7667 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7668 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7669
7670<h5>Examples:</h5>
7671<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7672%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7673%ptr = bitcast i8* %mallocP to i32*
7674 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7675%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7676 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7677%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7678 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7679%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7680 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7681%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7682 <i>; yields {i32}:result3 = 8</i>
7683%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7684</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7685
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7686</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7687
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7688</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7689
7690<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7691<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7692 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7693</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7694
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7695<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7696
7697<p>This class of intrinsics exists to information about the lifetime of memory
7698 objects and ranges where variables are immutable.</p>
7699
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7700<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7701<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7702 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7703</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7704
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7705<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7706
7707<h5>Syntax:</h5>
7708<pre>
7709 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7710</pre>
7711
7712<h5>Overview:</h5>
7713<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7714 object's lifetime.</p>
7715
7716<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7717<p>The first argument is a constant integer representing the size of the
7718 object, or -1 if it is variable sized. The second argument is a pointer to
7719 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7720
7721<h5>Semantics:</h5>
7722<p>This intrinsic indicates that before this point in the code, the value of the
7723 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]7724 never be used and has an undefined value. A load from the pointer that
7725 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7726 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7727
7728</div>
7729
7730<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7731<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7732 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7733</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7734
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7735<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7736
7737<h5>Syntax:</h5>
7738<pre>
7739 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7740</pre>
7741
7742<h5>Overview:</h5>
7743<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7744 object's lifetime.</p>
7745
7746<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7747<p>The first argument is a constant integer representing the size of the
7748 object, or -1 if it is variable sized. The second argument is a pointer to
7749 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7750
7751<h5>Semantics:</h5>
7752<p>This intrinsic indicates that after this point in the code, the value of the
7753 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7754 never be used and has an undefined value. Any stores into the memory object
7755 following this intrinsic may be removed as dead.
7756
7757</div>
7758
7759<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7760<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7761 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7762</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7763
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7764<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7765
7766<h5>Syntax:</h5>
7767<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]7768 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7769</pre>
7770
7771<h5>Overview:</h5>
7772<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7773 a memory object will not change.</p>
7774
7775<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7776<p>The first argument is a constant integer representing the size of the
7777 object, or -1 if it is variable sized. The second argument is a pointer to
7778 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7779
7780<h5>Semantics:</h5>
7781<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7782 the return value, the referenced memory location is constant and
7783 unchanging.</p>
7784
7785</div>
7786
7787<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7788<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7789 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7790</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7791
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7792<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7793
7794<h5>Syntax:</h5>
7795<pre>
7796 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7797</pre>
7798
7799<h5>Overview:</h5>
7800<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7801 a memory object are mutable.</p>
7802
7803<h5>Arguments:</h5>
7804<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7805 The second argument is a constant integer representing the size of the
7806 object, or -1 if it is variable sized and the third argument is a pointer
7807 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7808
7809<h5>Semantics:</h5>
7810<p>This intrinsic indicates that the memory is mutable again.</p>
7811
7812</div>
7813
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7814</div>
7815
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7816<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7817<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7818 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7819</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7820
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7821<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7822
7823<p>This class of intrinsics is designed to be generic and has no specific
7824 purpose.</p>
7825
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7826<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7827<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7828 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7829</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7831<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7832
7833<h5>Syntax:</h5>
7834<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7835 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]7836</pre>
7837
7838<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7839<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7840
7841<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7842<p>The first argument is a pointer to a value, the second is a pointer to a
7843 global string, the third is a pointer to a global string which is the source
7844 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7845
7846<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7847<p>This intrinsic allows annotation of local variables with arbitrary strings.
7848 This can be useful for special purpose optimizations that want to look for
7849 these annotations. These have no other defined use, they are ignored by code
7850 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7851
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7852</div>
7853
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7854<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7855<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7856 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7857</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7858
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7859<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7860
7861<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7862<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7863 any integer bit width.</p>
7864
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7865<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7866 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7867 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7868 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7869 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7870 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]7871</pre>
7872
7873<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7874<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7875
7876<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7877<p>The first argument is an integer value (result of some expression), the
7878 second is a pointer to a global string, the third is a pointer to a global
7879 string which is the source file name, and the last argument is the line
7880 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7881
7882<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7883<p>This intrinsic allows annotations to be put on arbitrary expressions with
7884 arbitrary strings. This can be useful for special purpose optimizations that
7885 want to look for these annotations. These have no other defined use, they
7886 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7887
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7888</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7889
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7890<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7891<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7892 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7893</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7894
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7895<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7896
7897<h5>Syntax:</h5>
7898<pre>
7899 declare void @llvm.trap()
7900</pre>
7901
7902<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7903<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7904
7905<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7906<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7907
7908<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7909<p>This intrinsics is lowered to the target dependent trap instruction. If the
7910 target does not have a trap instruction, this intrinsic will be lowered to
7911 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7912
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7913</div>
7914
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7915<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7916<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7917 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7918</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7919
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7920<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7921
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7922<h5>Syntax:</h5>
7923<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7924 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7925</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7926
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7927<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7928<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7929 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7930 ensure that it is placed on the stack before local variables.</p>
7931
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7932<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7933<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7934 arguments. The first argument is the value loaded from the stack
7935 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7936 that has enough space to hold the value of the guard.</p>
7937
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7938<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7939<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7940 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7941 stack. This is to ensure that if a local variable on the stack is
7942 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7943 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7944 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7945 function.</p>
7946
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7947</div>
7948
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7949<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7950<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7951 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7952</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7953
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7954<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7955
7956<h5>Syntax:</h5>
7957<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7958 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
7959 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7960</pre>
7961
7962<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7963<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
7964 the optimizers to determine at compile time whether a) an operation (like
7965 memcpy) will overflow a buffer that corresponds to an object, or b) that a
7966 runtime check for overflow isn't necessary. An object in this context means
7967 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7968
7969<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7970<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7971 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7972 is a boolean 0 or 1. This argument determines whether you want the
7973 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7974 1, variables are not allowed.</p>
7975
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7976<h5>Semantics:</h5>
7977<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7978 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
7979 depending on the <tt>type</tt> argument, if the size cannot be determined at
7980 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7981
7982</div>
7983
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7984</div>
7985
7986</div>
7987
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7988<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7989<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7990<address>
7991 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7992 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7993 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7994 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7995
7996 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]7997 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7998 Last modified: $Date$
7999</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8000
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8001</body>
8002</html>