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gerrit-public.fairphone.software / platform / external / llvm / aee0f453c5a801cee59178942180eac12f3fe670 / . / 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>
Bill Wendlingf7f06102011-10-11 06:41:28 +0000[diff] [blame]38 <li><a href="#linkage_external">'<tt>external</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]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>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a>
104 <ol>
105 <li><a href="#tbaa">'<tt>tbaa</tt>' Metadata</a></li>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]106 <li><a href="#fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a></li>
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]109 </ol>
110 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
112 <ol>
113 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]114 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
115 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]116 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
117 Global Variable</a></li>
118 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
119 Global Variable</a></li>
120 </ol>
121 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]122 <li><a href="#instref">Instruction Reference</a>
123 <ol>
124 <li><a href="#terminators">Terminator Instructions</a>
125 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
127 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]128 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]129 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]130 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]132 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]133 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]134 </ol>
135 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]136 <li><a href="#binaryops">Binary Operations</a>
137 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]138 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]139 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]141 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]143 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]144 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
145 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
146 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]147 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
148 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
149 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]150 </ol>
151 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]152 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
153 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]154 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
155 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
156 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]157 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]158 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]159 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]160 </ol>
161 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]162 <li><a href="#vectorops">Vector Operations</a>
163 <ol>
164 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
165 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
166 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]167 </ol>
168 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]169 <li><a href="#aggregateops">Aggregate Operations</a>
170 <ol>
171 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
172 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
173 </ol>
174 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]175 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]176 <ol>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]177 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
178 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
179 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
180 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
181 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
182 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]183 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]184 </ol>
185 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]186 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]187 <ol>
188 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
189 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
190 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
191 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
192 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]193 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
194 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
195 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
196 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]197 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
198 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]199 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]200 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]201 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]202 <li><a href="#otherops">Other Operations</a>
203 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]204 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
205 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]206 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]207 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]208 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]209 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]210 <li><a href="#i_landingpad">'<tt>landingpad</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]211 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]213 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]214 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]215 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]216 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]217 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
218 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]219 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
220 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
221 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]222 </ol>
223 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]224 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
225 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]226 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
227 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
228 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]229 </ol>
230 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]231 <li><a href="#int_codegen">Code Generator Intrinsics</a>
232 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]233 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
234 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
235 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
236 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
237 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
238 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]239 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]240 </ol>
241 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]242 <li><a href="#int_libc">Standard C Library Intrinsics</a>
243 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]244 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
245 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
246 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
247 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
248 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]249 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
250 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
251 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]252 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
253 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]254 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]255 </ol>
256 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]257 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]258 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]259 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]260 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
261 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
262 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]263 </ol>
264 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]265 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
266 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]267 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
268 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
269 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
270 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
271 <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]272 <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]273 </ol>
274 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]275 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
276 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]277 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
278 <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]279 </ol>
280 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]281 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]282 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]283 <li><a href="#int_trampoline">Trampoline Intrinsics</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]284 <ol>
285 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]286 <li><a href="#int_at">'<tt>llvm.adjust.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]287 </ol>
288 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]289 <li><a href="#int_memorymarkers">Memory Use Markers</a>
290 <ol>
291 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
292 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
293 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
294 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
295 </ol>
296 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]297 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]298 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]299 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]300 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]301 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]302 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]303 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]304 '<tt>llvm.trap</tt>' Intrinsic</a></li>
305 <li><a href="#int_stackprotector">
306 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]307 <li><a href="#int_objectsize">
308 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]309 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]310 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]311 </ol>
312 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]313</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
315<div class="doc_author">
316 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
317 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]318</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]319
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]320<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]321<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]322<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]324<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]325
326<p>This document is a reference manual for the LLVM assembly language. LLVM is
327 a Static Single Assignment (SSA) based representation that provides type
328 safety, low-level operations, flexibility, and the capability of representing
329 'all' high-level languages cleanly. It is the common code representation
330 used throughout all phases of the LLVM compilation strategy.</p>
331
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]332</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]333
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]334<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]335<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]336<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]337
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]338<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]339
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]340<p>The LLVM code representation is designed to be used in three different forms:
341 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
342 for fast loading by a Just-In-Time compiler), and as a human readable
343 assembly language representation. This allows LLVM to provide a powerful
344 intermediate representation for efficient compiler transformations and
345 analysis, while providing a natural means to debug and visualize the
346 transformations. The three different forms of LLVM are all equivalent. This
347 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]349<p>The LLVM representation aims to be light-weight and low-level while being
350 expressive, typed, and extensible at the same time. It aims to be a
351 "universal IR" of sorts, by being at a low enough level that high-level ideas
352 may be cleanly mapped to it (similar to how microprocessors are "universal
353 IR's", allowing many source languages to be mapped to them). By providing
354 type information, LLVM can be used as the target of optimizations: for
355 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]356 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]357 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]358
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]359<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]360<h4>
361 <a name="wellformed">Well-Formedness</a>
362</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]363
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]364<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]365
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]366<p>It is important to note that this document describes 'well formed' LLVM
367 assembly language. There is a difference between what the parser accepts and
368 what is considered 'well formed'. For example, the following instruction is
369 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]371<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]372%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]373</pre>
374
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]375<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
376 LLVM infrastructure provides a verification pass that may be used to verify
377 that an LLVM module is well formed. This pass is automatically run by the
378 parser after parsing input assembly and by the optimizer before it outputs
379 bitcode. The violations pointed out by the verifier pass indicate bugs in
380 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]381
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]382</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]383
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]384</div>
385
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]386<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]388<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]389<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]390<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]391
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]392<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]393
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]394<p>LLVM identifiers come in two basic types: global and local. Global
395 identifiers (functions, global variables) begin with the <tt>'@'</tt>
396 character. Local identifiers (register names, types) begin with
397 the <tt>'%'</tt> character. Additionally, there are three different formats
398 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]400<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]401 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]402 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
403 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
404 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
405 other characters in their names can be surrounded with quotes. Special
406 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
407 ASCII code for the character in hexadecimal. In this way, any character
408 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]410 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]413 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]414 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]415</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]416
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]417<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]418 don't need to worry about name clashes with reserved words, and the set of
419 reserved words may be expanded in the future without penalty. Additionally,
420 unnamed identifiers allow a compiler to quickly come up with a temporary
421 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]423<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]424 languages. There are keywords for different opcodes
425 ('<tt><a href="#i_add">add</a></tt>',
426 '<tt><a href="#i_bitcast">bitcast</a></tt>',
427 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
428 ('<tt><a href="#t_void">void</a></tt>',
429 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
430 reserved words cannot conflict with variable names, because none of them
431 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432
433<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]434 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]435
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]436<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]438<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]439%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440</pre>
441
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]442<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]444<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]445%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446</pre>
447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]448<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]450<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]451%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
452%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]453%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454</pre>
455
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]456<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
457 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]459<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]460 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]461 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]462
463 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]464 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]466 <li>Unnamed temporaries are numbered sequentially</li>
467</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]469<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]470 demonstrating instructions, we will follow an instruction with a comment that
471 defines the type and name of value produced. Comments are shown in italic
472 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]474</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475
476<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]477<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]478<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]479<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]480<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]481<h3>
482 <a name="modulestructure">Module Structure</a>
483</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]485<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]486
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]487<p>LLVM programs are composed of "Module"s, each of which is a translation unit
488 of the input programs. Each module consists of functions, global variables,
489 and symbol table entries. Modules may be combined together with the LLVM
490 linker, which merges function (and global variable) definitions, resolves
491 forward declarations, and merges symbol table entries. Here is an example of
492 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]494<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]495<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]496<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]497
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]498<i>; External declaration of the puts function</i>&nbsp;
499<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]500
501<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]502define i32 @main() { <i>; i32()* </i>&nbsp;
503 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
504 %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]505
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]506 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
507 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
508 <a href="#i_ret">ret</a> i32 0&nbsp;
509}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]510
511<i>; Named metadata</i>
512!1 = metadata !{i32 41}
513!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]514</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]515
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]516<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]517 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]518 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]519 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
520 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]521
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]522<p>In general, a module is made up of a list of global values, where both
523 functions and global variables are global values. Global values are
524 represented by a pointer to a memory location (in this case, a pointer to an
525 array of char, and a pointer to a function), and have one of the
526 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]528</div>
529
530<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]531<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]532 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]533</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]534
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]535<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]536
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]537<p>All Global Variables and Functions have one of the following types of
538 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]539
540<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]541 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]542 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
543 by objects in the current module. In particular, linking code into a
544 module with an private global value may cause the private to be renamed as
545 necessary to avoid collisions. Because the symbol is private to the
546 module, all references can be updated. This doesn't show up in any symbol
547 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]548
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]549 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]550 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
551 assembler and evaluated by the linker. Unlike normal strong symbols, they
552 are removed by the linker from the final linked image (executable or
553 dynamic library).</dd>
554
555 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
556 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
557 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
558 linker. The symbols are removed by the linker from the final linked image
559 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]560
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]561 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
562 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
563 of the object is not taken. For instance, functions that had an inline
564 definition, but the compiler decided not to inline it. Note,
565 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
566 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
567 visibility. The symbols are removed by the linker from the final linked
568 image (executable or dynamic library).</dd>
569
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]571 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]572 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
573 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]574
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]576 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]577 into the object file corresponding to the LLVM module. They exist to
578 allow inlining and other optimizations to take place given knowledge of
579 the definition of the global, which is known to be somewhere outside the
580 module. Globals with <tt>available_externally</tt> linkage are allowed to
581 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
582 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]583
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]585 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]586 the same name when linkage occurs. This can be used to implement
587 some forms of inline functions, templates, or other code which must be
588 generated in each translation unit that uses it, but where the body may
589 be overridden with a more definitive definition later. Unreferenced
590 <tt>linkonce</tt> globals are allowed to be discarded. Note that
591 <tt>linkonce</tt> linkage does not actually allow the optimizer to
592 inline the body of this function into callers because it doesn't know if
593 this definition of the function is the definitive definition within the
594 program or whether it will be overridden by a stronger definition.
595 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
596 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]597
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]598 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]599 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
600 <tt>linkonce</tt> linkage, except that unreferenced globals with
601 <tt>weak</tt> linkage may not be discarded. This is used for globals that
602 are declared "weak" in C source code.</dd>
603
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]604 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]605 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
606 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
607 global scope.
608 Symbols with "<tt>common</tt>" linkage are merged in the same way as
609 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]610 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]611 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]612 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
613 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]614
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]615
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]616 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]617 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]618 pointer to array type. When two global variables with appending linkage
619 are linked together, the two global arrays are appended together. This is
620 the LLVM, typesafe, equivalent of having the system linker append together
621 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]622
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]623 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]624 <dd>The semantics of this linkage follow the ELF object file model: the symbol
625 is weak until linked, if not linked, the symbol becomes null instead of
626 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]627
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
629 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]630 <dd>Some languages allow differing globals to be merged, such as two functions
631 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]632 that only equivalent globals are ever merged (the "one definition rule"
633 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]634 and <tt>weak_odr</tt> linkage types to indicate that the global will only
635 be merged with equivalent globals. These linkage types are otherwise the
636 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]637
Bill Wendling5c3a9f72011-11-04 20:40:41 +0000[diff] [blame]638 <dt><tt><b><a name="linkage_external">external</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]639 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]640 visible, meaning that it participates in linkage and can be used to
641 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]642</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]643
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]644<p>The next two types of linkage are targeted for Microsoft Windows platform
645 only. They are designed to support importing (exporting) symbols from (to)
646 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]647
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]648<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]649 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]650 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]651 or variable via a global pointer to a pointer that is set up by the DLL
652 exporting the symbol. On Microsoft Windows targets, the pointer name is
653 formed by combining <code>__imp_</code> and the function or variable
654 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]655
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]656 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]657 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]658 pointer to a pointer in a DLL, so that it can be referenced with the
659 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
660 name is formed by combining <code>__imp_</code> and the function or
661 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]662</dl>
663
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]664<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
665 another module defined a "<tt>.LC0</tt>" variable and was linked with this
666 one, one of the two would be renamed, preventing a collision. Since
667 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
668 declarations), they are accessible outside of the current module.</p>
669
670<p>It is illegal for a function <i>declaration</i> to have any linkage type
Bill Wendlingf7f06102011-10-11 06:41:28 +0000[diff] [blame]671 other than <tt>external</tt>, <tt>dllimport</tt>
672 or <tt>extern_weak</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]673
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]674<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]675 or <tt>weak_odr</tt> linkages.</p>
676
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]677</div>
678
679<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]680<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]681 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]682</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]683
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]684<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]685
686<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]687 and <a href="#i_invoke">invokes</a> can all have an optional calling
688 convention specified for the call. The calling convention of any pair of
689 dynamic caller/callee must match, or the behavior of the program is
690 undefined. The following calling conventions are supported by LLVM, and more
691 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]692
693<dl>
694 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]695 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]696 specified) matches the target C calling conventions. This calling
697 convention supports varargs function calls and tolerates some mismatch in
698 the declared prototype and implemented declaration of the function (as
699 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]700
701 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]702 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]703 (e.g. by passing things in registers). This calling convention allows the
704 target to use whatever tricks it wants to produce fast code for the
705 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]706 (Application Binary Interface).
707 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]708 when this or the GHC convention is used.</a> This calling convention
709 does not support varargs and requires the prototype of all callees to
710 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]711
712 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]713 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]714 as possible under the assumption that the call is not commonly executed.
715 As such, these calls often preserve all registers so that the call does
716 not break any live ranges in the caller side. This calling convention
717 does not support varargs and requires the prototype of all callees to
718 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]719
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]720 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
721 <dd>This calling convention has been implemented specifically for use by the
722 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
723 It passes everything in registers, going to extremes to achieve this by
724 disabling callee save registers. This calling convention should not be
725 used lightly but only for specific situations such as an alternative to
726 the <em>register pinning</em> performance technique often used when
727 implementing functional programming languages.At the moment only X86
728 supports this convention and it has the following limitations:
729 <ul>
730 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
731 floating point types are supported.</li>
732 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
733 6 floating point parameters.</li>
734 </ul>
735 This calling convention supports
736 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
737 requires both the caller and callee are using it.
738 </dd>
739
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]740 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]741 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]742 target-specific calling conventions to be used. Target specific calling
743 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]744</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]745
746<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]747 support Pascal conventions or any other well-known target-independent
748 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]749
750</div>
751
752<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]753<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]754 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]755</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]756
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]757<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]758
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]759<p>All Global Variables and Functions have one of the following visibility
760 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]761
762<dl>
763 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]764 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]765 that the declaration is visible to other modules and, in shared libraries,
766 means that the declared entity may be overridden. On Darwin, default
767 visibility means that the declaration is visible to other modules. Default
768 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]769
770 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]771 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]772 object if they are in the same shared object. Usually, hidden visibility
773 indicates that the symbol will not be placed into the dynamic symbol
774 table, so no other module (executable or shared library) can reference it
775 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]776
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]777 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]778 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]779 the dynamic symbol table, but that references within the defining module
780 will bind to the local symbol. That is, the symbol cannot be overridden by
781 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]782</dl>
783
784</div>
785
786<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]787<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]788 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]789</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]790
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]791<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]792
793<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]794 it easier to read the IR and make the IR more condensed (particularly when
795 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]796
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]797<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]798%mytype = type { %mytype*, i32 }
799</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]800
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]801<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]802 "<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]803 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]804
805<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]806 and that you can therefore specify multiple names for the same type. This
807 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
808 uses structural typing, the name is not part of the type. When printing out
809 LLVM IR, the printer will pick <em>one name</em> to render all types of a
810 particular shape. This means that if you have code where two different
811 source types end up having the same LLVM type, that the dumper will sometimes
812 print the "wrong" or unexpected type. This is an important design point and
813 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]814
815</div>
816
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]817<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]818<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]819 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]820</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]821
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]822<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]823
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]824<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]825 instead of run-time. Global variables may optionally be initialized, may
826 have an explicit section to be placed in, and may have an optional explicit
827 alignment specified. A variable may be defined as "thread_local", which
828 means that it will not be shared by threads (each thread will have a
829 separated copy of the variable). A variable may be defined as a global
830 "constant," which indicates that the contents of the variable
831 will <b>never</b> be modified (enabling better optimization, allowing the
832 global data to be placed in the read-only section of an executable, etc).
833 Note that variables that need runtime initialization cannot be marked
834 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]835
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]836<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
837 constant, even if the final definition of the global is not. This capability
838 can be used to enable slightly better optimization of the program, but
839 requires the language definition to guarantee that optimizations based on the
840 'constantness' are valid for the translation units that do not include the
841 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]842
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]843<p>As SSA values, global variables define pointer values that are in scope
844 (i.e. they dominate) all basic blocks in the program. Global variables
845 always define a pointer to their "content" type because they describe a
846 region of memory, and all memory objects in LLVM are accessed through
847 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]848
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]849<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
850 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]851 like this can be merged with other constants if they have the same
852 initializer. Note that a constant with significant address <em>can</em>
853 be merged with a <tt>unnamed_addr</tt> constant, the result being a
854 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]855
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]856<p>A global variable may be declared to reside in a target-specific numbered
857 address space. For targets that support them, address spaces may affect how
858 optimizations are performed and/or what target instructions are used to
859 access the variable. The default address space is zero. The address space
860 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]861
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]862<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]863 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]864
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]865<p>An explicit alignment may be specified for a global, which must be a power
866 of 2. If not present, or if the alignment is set to zero, the alignment of
867 the global is set by the target to whatever it feels convenient. If an
868 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]869 alignment. Targets and optimizers are not allowed to over-align the global
870 if the global has an assigned section. In this case, the extra alignment
871 could be observable: for example, code could assume that the globals are
872 densely packed in their section and try to iterate over them as an array,
873 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]874
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]875<p>For example, the following defines a global in a numbered address space with
876 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]877
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]878<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]879@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]880</pre>
881
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]882</div>
883
884
885<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]886<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]887 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]888</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]890<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]891
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]892<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]893 optional <a href="#linkage">linkage type</a>, an optional
894 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]895 <a href="#callingconv">calling convention</a>,
896 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]897 <a href="#paramattrs">parameter attribute</a> for the return type, a function
898 name, a (possibly empty) argument list (each with optional
899 <a href="#paramattrs">parameter attributes</a>), optional
900 <a href="#fnattrs">function attributes</a>, an optional section, an optional
901 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
902 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]903
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]904<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
905 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]906 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]907 <a href="#callingconv">calling convention</a>,
908 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]909 <a href="#paramattrs">parameter attribute</a> for the return type, a function
910 name, a possibly empty list of arguments, an optional alignment, and an
911 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]912
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]913<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]914 (Control Flow Graph) for the function. Each basic block may optionally start
915 with a label (giving the basic block a symbol table entry), contains a list
916 of instructions, and ends with a <a href="#terminators">terminator</a>
917 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]918
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]919<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]920 executed on entrance to the function, and it is not allowed to have
921 predecessor basic blocks (i.e. there can not be any branches to the entry
922 block of a function). Because the block can have no predecessors, it also
923 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]924
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]925<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]926 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]927
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]928<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]929 the alignment is set to zero, the alignment of the function is set by the
930 target to whatever it feels convenient. If an explicit alignment is
931 specified, the function is forced to have at least that much alignment. All
932 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]933
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]934<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
Bill Wendling5c3a9f72011-11-04 20:40:41 +0000[diff] [blame]935 be significant and two identical functions can be merged.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]936
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]937<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]938<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]939define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]940 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
941 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
942 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
943 [<a href="#gc">gc</a>] { ... }
944</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]945
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]946</div>
947
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]948<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]949<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]950 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]951</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]952
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]953<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]954
955<p>Aliases act as "second name" for the aliasee value (which can be either
956 function, global variable, another alias or bitcast of global value). Aliases
957 may have an optional <a href="#linkage">linkage type</a>, and an
958 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]959
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]960<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]961<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]962@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]963</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]964
965</div>
966
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]967<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]968<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]969 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]970</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]971
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]972<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]973
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]974<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]975 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]976 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]977
978<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]979<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]980; Some unnamed metadata nodes, which are referenced by the named metadata.
981!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]982!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]983!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]984; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]985!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]986</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]987
988</div>
989
990<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]991<h3>
992 <a name="paramattrs">Parameter Attributes</a>
993</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]994
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]995<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]996
997<p>The return type and each parameter of a function type may have a set of
998 <i>parameter attributes</i> associated with them. Parameter attributes are
999 used to communicate additional information about the result or parameters of
1000 a function. Parameter attributes are considered to be part of the function,
1001 not of the function type, so functions with different parameter attributes
1002 can have the same function type.</p>
1003
1004<p>Parameter attributes are simple keywords that follow the type specified. If
1005 multiple parameter attributes are needed, they are space separated. For
1006 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1007
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1008<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1009declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1010declare i32 @atoi(i8 zeroext)
1011declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1012</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1014<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1015 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1016
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1017<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1018
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1019<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1020 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1021 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1022 should be zero-extended to the extent required by the target's ABI (which
1023 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1024 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1025
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1028 should be sign-extended to the extent required by the target's ABI (which
1029 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1030 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1031
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1032 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This indicates that this parameter or return value should be treated in a
1034 special target-dependent fashion during while emitting code for a function
1035 call or return (usually, by putting it in a register as opposed to memory,
1036 though some targets use it to distinguish between two different kinds of
1037 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1038
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1039 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1040 <dd><p>This indicates that the pointer parameter should really be passed by
1041 value to the function. The attribute implies that a hidden copy of the
1042 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1043 is made between the caller and the callee, so the callee is unable to
1044 modify the value in the callee. This attribute is only valid on LLVM
1045 pointer arguments. It is generally used to pass structs and arrays by
1046 value, but is also valid on pointers to scalars. The copy is considered
1047 to belong to the caller not the callee (for example,
1048 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1049 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1050 values.</p>
1051
1052 <p>The byval attribute also supports specifying an alignment with
1053 the align attribute. It indicates the alignment of the stack slot to
1054 form and the known alignment of the pointer specified to the call site. If
1055 the alignment is not specified, then the code generator makes a
1056 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1057
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1058 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1059 <dd>This indicates that the pointer parameter specifies the address of a
1060 structure that is the return value of the function in the source program.
1061 This pointer must be guaranteed by the caller to be valid: loads and
1062 stores to the structure may be assumed by the callee to not to trap. This
1063 may only be applied to the first parameter. This is not a valid attribute
1064 for return values. </dd>
1065
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1066 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1067 <dd>This indicates that pointer values
1068 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1069 value do not alias pointer values which are not <i>based</i> on it,
1070 ignoring certain "irrelevant" dependencies.
1071 For a call to the parent function, dependencies between memory
1072 references from before or after the call and from those during the call
1073 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1074 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1075 The caller shares the responsibility with the callee for ensuring that
1076 these requirements are met.
1077 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1078 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1079<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1080 Note that this definition of <tt>noalias</tt> is intentionally
1081 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1082 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1083<br>
1084 For function return values, C99's <tt>restrict</tt> is not meaningful,
1085 while LLVM's <tt>noalias</tt> is.
1086 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1087
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1088 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1089 <dd>This indicates that the callee does not make any copies of the pointer
1090 that outlive the callee itself. This is not a valid attribute for return
1091 values.</dd>
1092
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1093 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1094 <dd>This indicates that the pointer parameter can be excised using the
1095 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1096 attribute for return values.</dd>
1097</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1098
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1099</div>
1100
1101<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1102<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1103 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1104</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1105
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1106<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1107
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1108<p>Each function may specify a garbage collector name, which is simply a
1109 string:</p>
1110
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1111<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1112define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1113</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1114
1115<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1116 collector which will cause the compiler to alter its output in order to
1117 support the named garbage collection algorithm.</p>
1118
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1119</div>
1120
1121<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1122<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1123 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1124</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1125
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1126<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1127
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1128<p>Function attributes are set to communicate additional information about a
1129 function. Function attributes are considered to be part of the function, not
1130 of the function type, so functions with different parameter attributes can
1131 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1132
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1133<p>Function attributes are simple keywords that follow the type specified. If
1134 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1135
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1136<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1137define void @f() noinline { ... }
1138define void @f() alwaysinline { ... }
1139define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1140define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1141</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1142
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1143<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1144 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1145 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1146 the backend should forcibly align the stack pointer. Specify the
1147 desired alignment, which must be a power of two, in parentheses.
1148
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1149 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1150 <dd>This attribute indicates that the inliner should attempt to inline this
1151 function into callers whenever possible, ignoring any active inlining size
1152 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1153
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1154 <dt><tt><b>nonlazybind</b></tt></dt>
1155 <dd>This attribute suppresses lazy symbol binding for the function. This
1156 may make calls to the function faster, at the cost of extra program
1157 startup time if the function is not called during program startup.</dd>
1158
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1159 <dt><tt><b>inlinehint</b></tt></dt>
1160 <dd>This attribute indicates that the source code contained a hint that inlining
1161 this function is desirable (such as the "inline" keyword in C/C++). It
1162 is just a hint; it imposes no requirements on the inliner.</dd>
1163
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1164 <dt><tt><b>naked</b></tt></dt>
1165 <dd>This attribute disables prologue / epilogue emission for the function.
1166 This can have very system-specific consequences.</dd>
1167
1168 <dt><tt><b>noimplicitfloat</b></tt></dt>
1169 <dd>This attributes disables implicit floating point instructions.</dd>
1170
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1171 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1172 <dd>This attribute indicates that the inliner should never inline this
1173 function in any situation. This attribute may not be used together with
1174 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1175
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1176 <dt><tt><b>noredzone</b></tt></dt>
1177 <dd>This attribute indicates that the code generator should not use a red
1178 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1179
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1180 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1181 <dd>This function attribute indicates that the function never returns
1182 normally. This produces undefined behavior at runtime if the function
1183 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1184
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1185 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1186 <dd>This function attribute indicates that the function never returns with an
1187 unwind or exceptional control flow. If the function does unwind, its
1188 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1189
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1190 <dt><tt><b>optsize</b></tt></dt>
1191 <dd>This attribute suggests that optimization passes and code generator passes
1192 make choices that keep the code size of this function low, and otherwise
1193 do optimizations specifically to reduce code size.</dd>
1194
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1195 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1196 <dd>This attribute indicates that the function computes its result (or decides
1197 to unwind an exception) based strictly on its arguments, without
1198 dereferencing any pointer arguments or otherwise accessing any mutable
1199 state (e.g. memory, control registers, etc) visible to caller functions.
1200 It does not write through any pointer arguments
1201 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1202 changes any state visible to callers. This means that it cannot unwind
1203 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1204 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1205
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1206 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1207 <dd>This attribute indicates that the function does not write through any
1208 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1209 arguments) or otherwise modify any state (e.g. memory, control registers,
1210 etc) visible to caller functions. It may dereference pointer arguments
1211 and read state that may be set in the caller. A readonly function always
1212 returns the same value (or unwinds an exception identically) when called
1213 with the same set of arguments and global state. It cannot unwind an
1214 exception by calling the <tt>C++</tt> exception throwing methods, but may
1215 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1216
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1217 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1218 <dd>This attribute indicates that the function should emit a stack smashing
1219 protector. It is in the form of a "canary"&mdash;a random value placed on
1220 the stack before the local variables that's checked upon return from the
1221 function to see if it has been overwritten. A heuristic is used to
1222 determine if a function needs stack protectors or not.<br>
1223<br>
1224 If a function that has an <tt>ssp</tt> attribute is inlined into a
1225 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1226 function will have an <tt>ssp</tt> attribute.</dd>
1227
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1228 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1229 <dd>This attribute indicates that the function should <em>always</em> emit a
1230 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1231 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1232<br>
1233 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1234 function that doesn't have an <tt>sspreq</tt> attribute or which has
1235 an <tt>ssp</tt> attribute, then the resulting function will have
1236 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1237
1238 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1239 <dd>This attribute indicates that the ABI being targeted requires that
1240 an unwind table entry be produce for this function even if we can
1241 show that no exceptions passes by it. This is normally the case for
1242 the ELF x86-64 abi, but it can be disabled for some compilation
1243 units.</dd>
1244
Rafael Espindola25456ef2011-10-03 14:45:37 +0000[diff] [blame]1245 <dt><tt><b><a name="returns_twice">returns_twice</a></b></tt></dt>
1246 <dd>This attribute indicates that this function can return
1247 twice. The C <code>setjmp</code> is an example of such a function.
1248 The compiler disables some optimizations (like tail calls) in the caller of
1249 these functions.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1250</dl>
1251
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1252</div>
1253
1254<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1255<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1256 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1257</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1258
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1259<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1260
1261<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1262 the GCC "file scope inline asm" blocks. These blocks are internally
1263 concatenated by LLVM and treated as a single unit, but may be separated in
1264 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1265
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1266<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1267module asm "inline asm code goes here"
1268module asm "more can go here"
1269</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1270
1271<p>The strings can contain any character by escaping non-printable characters.
1272 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]1273 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1274
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1275<p>The inline asm code is simply printed to the machine code .s file when
1276 assembly code is generated.</p>
1277
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1278</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1279
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1280<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1281<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1282 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1283</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1284
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1285<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1286
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1287<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1288 data is to be laid out in memory. The syntax for the data layout is
1289 simply:</p>
1290
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1291<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1292target datalayout = "<i>layout specification</i>"
1293</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1294
1295<p>The <i>layout specification</i> consists of a list of specifications
1296 separated by the minus sign character ('-'). Each specification starts with
1297 a letter and may include other information after the letter to define some
1298 aspect of the data layout. The specifications accepted are as follows:</p>
1299
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1300<dl>
1301 <dt><tt>E</tt></dt>
1302 <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]1303 bits with the most significance have the lowest address location.</dd>
1304
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1305 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1306 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1307 the bits with the least significance have the lowest address
1308 location.</dd>
1309
Lang Hamesbb5b3f32011-10-10 23:42:08 +0000[diff] [blame]1310 <dt><tt>S<i>size</i></tt></dt>
1311 <dd>Specifies the natural alignment of the stack in bits. Alignment promotion
1312 of stack variables is limited to the natural stack alignment to avoid
1313 dynamic stack realignment. The stack alignment must be a multiple of
Lang Hames5f119a62011-10-11 17:50:14 +0000[diff] [blame]1314 8-bits. If omitted, the natural stack alignment defaults to "unspecified",
1315 which does not prevent any alignment promotions.</dd>
Lang Hamesbb5b3f32011-10-10 23:42:08 +0000[diff] [blame]1316
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1317 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1318 <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]1319 <i>preferred</i> alignments. All sizes are in bits. Specifying
1320 the <i>pref</i> alignment is optional. If omitted, the
1321 preceding <tt>:</tt> should be omitted too.</dd>
1322
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1323 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1324 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1325 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1326
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1327 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1328 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1329 <i>size</i>.</dd>
1330
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1331 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1332 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1333 <i>size</i>. Only values of <i>size</i> that are supported by the target
1334 will work. 32 (float) and 64 (double) are supported on all targets;
1335 80 or 128 (different flavors of long double) are also supported on some
1336 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1337
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1338 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1339 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1340 <i>size</i>.</dd>
1341
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1342 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1343 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1344 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1345
1346 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1347 <dd>This specifies a set of native integer widths for the target CPU
1348 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1349 "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]1350 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1351 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1352</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1353
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1354<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1355 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1356 specifications in the <tt>datalayout</tt> keyword. The default specifications
1357 are given in this list:</p>
1358
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1359<ul>
1360 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1361 <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]1362 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1363 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1364 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1365 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1366 <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]1367 alignment of 64-bits</li>
1368 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1369 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1370 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1371 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1372 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1373 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1374</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1375
1376<p>When LLVM is determining the alignment for a given type, it uses the
1377 following rules:</p>
1378
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1379<ol>
1380 <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]1381 specification is used.</li>
1382
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1383 <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]1384 smallest integer type that is larger than the bitwidth of the sought type
1385 is used. If none of the specifications are larger than the bitwidth then
1386 the the largest integer type is used. For example, given the default
1387 specifications above, the i7 type will use the alignment of i8 (next
1388 largest) while both i65 and i256 will use the alignment of i64 (largest
1389 specified).</li>
1390
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1391 <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]1392 largest vector type that is smaller than the sought vector type will be
1393 used as a fall back. This happens because &lt;128 x double&gt; can be
1394 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1395</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1396
Chris Lattner6509f502011-10-11 23:01:39 +0000[diff] [blame]1397<p>The function of the data layout string may not be what you expect. Notably,
1398 this is not a specification from the frontend of what alignment the code
1399 generator should use.</p>
1400
1401<p>Instead, if specified, the target data layout is required to match what the
1402 ultimate <em>code generator</em> expects. This string is used by the
1403 mid-level optimizers to
1404 improve code, and this only works if it matches what the ultimate code
1405 generator uses. If you would like to generate IR that does not embed this
1406 target-specific detail into the IR, then you don't have to specify the
1407 string. This will disable some optimizations that require precise layout
1408 information, but this also prevents those optimizations from introducing
1409 target specificity into the IR.</p>
1410
1411
1412
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1413</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1414
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1415<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1416<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1417 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1418</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1419
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1420<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1421
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1422<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1423with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1424is undefined. Pointer values are associated with address ranges
1425according to the following rules:</p>
1426
1427<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1428 <li>A pointer value is associated with the addresses associated with
1429 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1430 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1431 range of the variable's storage.</li>
1432 <li>The result value of an allocation instruction is associated with
1433 the address range of the allocated storage.</li>
1434 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1435 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1436 <li>An integer constant other than zero or a pointer value returned
1437 from a function not defined within LLVM may be associated with address
1438 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1439 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1440 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1441</ul>
1442
1443<p>A pointer value is <i>based</i> on another pointer value according
1444 to the following rules:</p>
1445
1446<ul>
1447 <li>A pointer value formed from a
1448 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1449 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1450 <li>The result value of a
1451 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1452 of the <tt>bitcast</tt>.</li>
1453 <li>A pointer value formed by an
1454 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1455 pointer values that contribute (directly or indirectly) to the
1456 computation of the pointer's value.</li>
1457 <li>The "<i>based</i> on" relationship is transitive.</li>
1458</ul>
1459
1460<p>Note that this definition of <i>"based"</i> is intentionally
1461 similar to the definition of <i>"based"</i> in C99, though it is
1462 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1463
1464<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1465<tt><a href="#i_load">load</a></tt> merely indicates the size and
1466alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1467interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1468<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1469and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1470
1471<p>Consequently, type-based alias analysis, aka TBAA, aka
1472<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1473LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1474additional information which specialized optimization passes may use
1475to implement type-based alias analysis.</p>
1476
1477</div>
1478
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1479<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1480<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1481 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1482</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1483
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1484<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1485
1486<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1487href="#i_store"><tt>store</tt></a>s, and <a
1488href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1489The optimizers must not change the number of volatile operations or change their
1490order of execution relative to other volatile operations. The optimizers
1491<i>may</i> change the order of volatile operations relative to non-volatile
1492operations. This is not Java's "volatile" and has no cross-thread
1493synchronization behavior.</p>
1494
1495</div>
1496
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1497<!-- ======================================================================= -->
1498<h3>
1499 <a name="memmodel">Memory Model for Concurrent Operations</a>
1500</h3>
1501
1502<div>
1503
1504<p>The LLVM IR does not define any way to start parallel threads of execution
1505or to register signal handlers. Nonetheless, there are platform-specific
1506ways to create them, and we define LLVM IR's behavior in their presence. This
1507model is inspired by the C++0x memory model.</p>
1508
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1509<p>For a more informal introduction to this model, see the
1510<a href="Atomics.html">LLVM Atomic Instructions and Concurrency Guide</a>.
1511
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1512<p>We define a <i>happens-before</i> partial order as the least partial order
1513that</p>
1514<ul>
1515 <li>Is a superset of single-thread program order, and</li>
1516 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1517 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1518 by platform-specific techniques, like pthread locks, thread
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1519 creation, thread joining, etc., and by atomic instructions.
1520 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1521 </li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1522</ul>
1523
1524<p>Note that program order does not introduce <i>happens-before</i> edges
1525between a thread and signals executing inside that thread.</p>
1526
1527<p>Every (defined) read operation (load instructions, memcpy, atomic
1528loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1529(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1530stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1531initialized globals are considered to have a write of the initializer which is
1532atomic and happens before any other read or write of the memory in question.
1533For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1534any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1535
1536<ul>
1537 <li>If <var>write<sub>1</sub></var> happens before
1538 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1539 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1540 does not see <var>write<sub>1</sub></var>.
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]1541 <li>If <var>R<sub>byte</sub></var> happens before
1542 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1543 see <var>write<sub>3</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1544</ul>
1545
1546<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1547<ul>
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1548 <li>If <var>R</var> is volatile, the result is target-dependent. (Volatile
1549 is supposed to give guarantees which can support
1550 <code>sig_atomic_t</code> in C/C++, and may be used for accesses to
1551 addresses which do not behave like normal memory. It does not generally
1552 provide cross-thread synchronization.)
1553 <li>Otherwise, if there is no write to the same byte that happens before
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1554 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1555 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1556 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1557 <var>R<sub>byte</sub></var> returns the value written by that
1558 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1559 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1560 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1561 values written. See the <a href="#ordering">Atomic Memory Ordering
1562 Constraints</a> section for additional constraints on how the choice
1563 is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1564 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1565</ul>
1566
1567<p><var>R</var> returns the value composed of the series of bytes it read.
1568This implies that some bytes within the value may be <tt>undef</tt>
1569<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1570defines the semantics of the operation; it doesn't mean that targets will
1571emit more than one instruction to read the series of bytes.</p>
1572
1573<p>Note that in cases where none of the atomic intrinsics are used, this model
1574places only one restriction on IR transformations on top of what is required
1575for single-threaded execution: introducing a store to a byte which might not
Eli Friedman101c81d2011-08-02 01:15:34 +0000[diff] [blame]1576otherwise be stored is not allowed in general. (Specifically, in the case
1577where another thread might write to and read from an address, introducing a
1578store can change a load that may see exactly one write into a load that may
1579see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1580
1581<!-- FIXME: This model assumes all targets where concurrency is relevant have
1582a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1583none of the backends currently in the tree fall into this category; however,
1584there might be targets which care. If there are, we want a paragraph
1585like the following:
1586
1587Targets may specify that stores narrower than a certain width are not
1588available; on such a target, for the purposes of this model, treat any
1589non-atomic write with an alignment or width less than the minimum width
1590as if it writes to the relevant surrounding bytes.
1591-->
1592
1593</div>
1594
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1595<!-- ======================================================================= -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1596<h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1597 <a name="ordering">Atomic Memory Ordering Constraints</a>
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1598</h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1599
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1600<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1601
1602<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]1603<a href="#i_atomicrmw"><code>atomicrmw</code></a>,
1604<a href="#i_fence"><code>fence</code></a>,
1605<a href="#i_load"><code>atomic load</code></a>, and
Eli Friedman8fa281a2011-08-09 23:26:12 +0000[diff] [blame]1606<a href="#i_store"><code>atomic store</code></a>) take an ordering parameter
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1607that determines which other atomic instructions on the same address they
1608<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1609but are somewhat more colloquial. If these descriptions aren't precise enough,
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1610check those specs (see spec references in the
1611<a href="Atomic.html#introduction">atomics guide</a>).
1612<a href="#i_fence"><code>fence</code></a> instructions
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1613treat these orderings somewhat differently since they don't take an address.
1614See that instruction's documentation for details.</p>
1615
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1616<p>For a simpler introduction to the ordering constraints, see the
1617<a href="Atomics.html">LLVM Atomic Instructions and Concurrency Guide</a>.</p>
1618
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1619<dl>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1620<dt><code>unordered</code></dt>
1621<dd>The set of values that can be read is governed by the happens-before
1622partial order. A value cannot be read unless some operation wrote it.
1623This is intended to provide a guarantee strong enough to model Java's
1624non-volatile shared variables. This ordering cannot be specified for
1625read-modify-write operations; it is not strong enough to make them atomic
1626in any interesting way.</dd>
1627<dt><code>monotonic</code></dt>
1628<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1629total order for modifications by <code>monotonic</code> operations on each
1630address. All modification orders must be compatible with the happens-before
1631order. There is no guarantee that the modification orders can be combined to
1632a global total order for the whole program (and this often will not be
1633possible). The read in an atomic read-modify-write operation
1634(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1635<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1636reads the value in the modification order immediately before the value it
1637writes. If one atomic read happens before another atomic read of the same
1638address, the later read must see the same value or a later value in the
1639address's modification order. This disallows reordering of
1640<code>monotonic</code> (or stronger) operations on the same address. If an
1641address is written <code>monotonic</code>ally by one thread, and other threads
1642<code>monotonic</code>ally read that address repeatedly, the other threads must
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1643eventually see the write. This corresponds to the C++0x/C1x
1644<code>memory_order_relaxed</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1645<dt><code>acquire</code></dt>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1646<dd>In addition to the guarantees of <code>monotonic</code>,
Eli Friedmanc264b2f2011-08-24 20:28:39 +0000[diff] [blame]1647a <i>synchronizes-with</i> edge may be formed with a <code>release</code>
1648operation. This is intended to model C++'s <code>memory_order_acquire</code>.</dd>
1649<dt><code>release</code></dt>
1650<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1651writes a value which is subsequently read by an <code>acquire</code> operation,
1652it <i>synchronizes-with</i> that operation. (This isn't a complete
1653description; see the C++0x definition of a release sequence.) This corresponds
1654to the C++0x/C1x <code>memory_order_release</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1655<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1656<code>acquire</code> and <code>release</code> operation on its address.
1657This corresponds to the C++0x/C1x <code>memory_order_acq_rel</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1658<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1659<dd>In addition to the guarantees of <code>acq_rel</code>
1660(<code>acquire</code> for an operation which only reads, <code>release</code>
1661for an operation which only writes), there is a global total order on all
1662sequentially-consistent operations on all addresses, which is consistent with
1663the <i>happens-before</i> partial order and with the modification orders of
1664all the affected addresses. Each sequentially-consistent read sees the last
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1665preceding write to the same address in this global order. This corresponds
1666to the C++0x/C1x <code>memory_order_seq_cst</code> and Java volatile.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1667</dl>
1668
1669<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1670it only <i>synchronizes with</i> or participates in modification and seq_cst
1671total orderings with other operations running in the same thread (for example,
1672in signal handlers).</p>
1673
1674</div>
1675
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1676</div>
1677
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1678<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1679<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1680<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1681
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1682<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1683
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1684<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1685 intermediate representation. Being typed enables a number of optimizations
1686 to be performed on the intermediate representation directly, without having
1687 to do extra analyses on the side before the transformation. A strong type
1688 system makes it easier to read the generated code and enables novel analyses
1689 and transformations that are not feasible to perform on normal three address
1690 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1691
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1692<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1693<h3>
1694 <a name="t_classifications">Type Classifications</a>
1695</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1696
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1697<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1698
1699<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1700
1701<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1702 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1703 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1704 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1705 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1706 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1707 </tr>
1708 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1709 <td><a href="#t_floating">floating point</a></td>
1710 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1711 </tr>
1712 <tr>
1713 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1714 <td><a href="#t_integer">integer</a>,
1715 <a href="#t_floating">floating point</a>,
1716 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1717 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1718 <a href="#t_struct">structure</a>,
1719 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1720 <a href="#t_label">label</a>,
1721 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1722 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1723 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1724 <tr>
1725 <td><a href="#t_primitive">primitive</a></td>
1726 <td><a href="#t_label">label</a>,
1727 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1728 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1729 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1730 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1731 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1732 </tr>
1733 <tr>
1734 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1735 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1736 <a href="#t_function">function</a>,
1737 <a href="#t_pointer">pointer</a>,
1738 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1739 <a href="#t_vector">vector</a>,
1740 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1741 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1742 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1743 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1744</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1745
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1746<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1747 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1748 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1749
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1750</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1751
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1752<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1753<h3>
1754 <a name="t_primitive">Primitive Types</a>
1755</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1756
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1757<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1758
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1759<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1760 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1761
1762<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1763<h4>
1764 <a name="t_integer">Integer Type</a>
1765</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1766
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1767<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1768
1769<h5>Overview:</h5>
1770<p>The integer type is a very simple type that simply specifies an arbitrary
1771 bit width for the integer type desired. Any bit width from 1 bit to
1772 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1773
1774<h5>Syntax:</h5>
1775<pre>
1776 iN
1777</pre>
1778
1779<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1780 value.</p>
1781
1782<h5>Examples:</h5>
1783<table class="layout">
1784 <tr class="layout">
1785 <td class="left"><tt>i1</tt></td>
1786 <td class="left">a single-bit integer.</td>
1787 </tr>
1788 <tr class="layout">
1789 <td class="left"><tt>i32</tt></td>
1790 <td class="left">a 32-bit integer.</td>
1791 </tr>
1792 <tr class="layout">
1793 <td class="left"><tt>i1942652</tt></td>
1794 <td class="left">a really big integer of over 1 million bits.</td>
1795 </tr>
1796</table>
1797
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1798</div>
1799
1800<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1801<h4>
1802 <a name="t_floating">Floating Point Types</a>
1803</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1804
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1805<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1806
1807<table>
1808 <tbody>
1809 <tr><th>Type</th><th>Description</th></tr>
1810 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1811 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1812 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1813 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1814 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1815 </tbody>
1816</table>
1817
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1818</div>
1819
1820<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1821<h4>
1822 <a name="t_x86mmx">X86mmx Type</a>
1823</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1824
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1825<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1826
1827<h5>Overview:</h5>
1828<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>
1829
1830<h5>Syntax:</h5>
1831<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1832 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1833</pre>
1834
1835</div>
1836
1837<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1838<h4>
1839 <a name="t_void">Void Type</a>
1840</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1841
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1842<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1843
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1844<h5>Overview:</h5>
1845<p>The void type does not represent any value and has no size.</p>
1846
1847<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1848<pre>
1849 void
1850</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1851
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1852</div>
1853
1854<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1855<h4>
1856 <a name="t_label">Label Type</a>
1857</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1858
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1859<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1860
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1861<h5>Overview:</h5>
1862<p>The label type represents code labels.</p>
1863
1864<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1865<pre>
1866 label
1867</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1868
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1869</div>
1870
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1871<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1872<h4>
1873 <a name="t_metadata">Metadata Type</a>
1874</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1875
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1876<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1877
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1878<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1879<p>The metadata type represents embedded metadata. No derived types may be
1880 created from metadata except for <a href="#t_function">function</a>
1881 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1882
1883<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1884<pre>
1885 metadata
1886</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1887
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1888</div>
1889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1890</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1891
1892<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1893<h3>
1894 <a name="t_derived">Derived Types</a>
1895</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1896
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1897<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1898
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1899<p>The real power in LLVM comes from the derived types in the system. This is
1900 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1901 useful types. Each of these types contain one or more element types which
1902 may be a primitive type, or another derived type. For example, it is
1903 possible to have a two dimensional array, using an array as the element type
1904 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1905
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1906<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1907<h4>
1908 <a name="t_aggregate">Aggregate Types</a>
1909</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1910
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1911<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1912
1913<p>Aggregate Types are a subset of derived types that can contain multiple
1914 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1915 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1916 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1917
1918</div>
1919
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1920<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1921<h4>
1922 <a name="t_array">Array Type</a>
1923</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1924
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1925<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1926
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1927<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1928<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1929 sequentially in memory. The array type requires a size (number of elements)
1930 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1931
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1932<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1933<pre>
1934 [&lt;# elements&gt; x &lt;elementtype&gt;]
1935</pre>
1936
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1938 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1939
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1940<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1941<table class="layout">
1942 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1943 <td class="left"><tt>[40 x i32]</tt></td>
1944 <td class="left">Array of 40 32-bit integer values.</td>
1945 </tr>
1946 <tr class="layout">
1947 <td class="left"><tt>[41 x i32]</tt></td>
1948 <td class="left">Array of 41 32-bit integer values.</td>
1949 </tr>
1950 <tr class="layout">
1951 <td class="left"><tt>[4 x i8]</tt></td>
1952 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1953 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1954</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1955<p>Here are some examples of multidimensional arrays:</p>
1956<table class="layout">
1957 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1958 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1959 <td class="left">3x4 array of 32-bit integer values.</td>
1960 </tr>
1961 <tr class="layout">
1962 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1963 <td class="left">12x10 array of single precision floating point values.</td>
1964 </tr>
1965 <tr class="layout">
1966 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1967 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1968 </tr>
1969</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1970
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1971<p>There is no restriction on indexing beyond the end of the array implied by
1972 a static type (though there are restrictions on indexing beyond the bounds
1973 of an allocated object in some cases). This means that single-dimension
1974 'variable sized array' addressing can be implemented in LLVM with a zero
1975 length array type. An implementation of 'pascal style arrays' in LLVM could
1976 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1977
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1978</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1979
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1980<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1981<h4>
1982 <a name="t_function">Function Type</a>
1983</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1984
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1985<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1986
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1987<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1988<p>The function type can be thought of as a function signature. It consists of
1989 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]1990 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1991
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1992<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1993<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1994 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1995</pre>
1996
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1997<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]1998 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1999 which indicates that the function takes a variable number of arguments.
2000 Variable argument functions can access their arguments with
2001 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2002 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]2003 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2004
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2005<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2006<table class="layout">
2007 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2008 <td class="left"><tt>i32 (i32)</tt></td>
2009 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2010 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2011 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2012 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]2013 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2014 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2015 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
2016 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2017 </td>
2018 </tr><tr class="layout">
2019 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2020 <td class="left">A vararg function that takes at least one
2021 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2022 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2023 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2024 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2025 </tr><tr class="layout">
2026 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2027 <td class="left">A function taking an <tt>i32</tt>, returning a
2028 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2029 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2030 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2031</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2032
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2033</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2034
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2035<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2036<h4>
2037 <a name="t_struct">Structure Type</a>
2038</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2039
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2040<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2041
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2042<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2043<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2044 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]2045
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]2046<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2047 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2048 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2049 Structures in registers are accessed using the
2050 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2051 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2052
2053<p>Structures may optionally be "packed" structures, which indicate that the
2054 alignment of the struct is one byte, and that there is no padding between
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2055 the elements. In non-packed structs, padding between field types is inserted
2056 as defined by the TargetData string in the module, which is required to match
Chris Lattnere4617b02011-10-11 23:02:17 +0000[diff] [blame]2057 what the underlying code generator expects.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2058
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2059<p>Structures can either be "literal" or "identified". A literal structure is
2060 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) whereas identified
2061 types are always defined at the top level with a name. Literal types are
2062 uniqued by their contents and can never be recursive or opaque since there is
Chris Lattneraa175c32011-08-12 18:12:40 +0000[diff] [blame]2063 no way to write one. Identified types can be recursive, can be opaqued, and are
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2064 never uniqued.
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2065</p>
2066
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2067<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2068<pre>
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2069 %T1 = type { &lt;type list&gt; } <i>; Identified normal struct type</i>
2070 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Identified packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2071</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2073<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2074<table class="layout">
2075 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2076 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2077 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2078 </tr>
2079 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2080 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2081 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2082 second element is a <a href="#t_pointer">pointer</a> to a
2083 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2084 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2085 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2086 <tr class="layout">
2087 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2088 <td class="left">A packed struct known to be 5 bytes in size.</td>
2089 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2090</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2091
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2092</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2093
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2094<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2095<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2096 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2097</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2098
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2099<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2100
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2101<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2102<p>Opaque structure types are used to represent named structure types that do
2103 not have a body specified. This corresponds (for example) to the C notion of
2104 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2105
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2106<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2107<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2108 %X = type opaque
2109 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2110</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2111
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2112<h5>Examples:</h5>
2113<table class="layout">
2114 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2115 <td class="left"><tt>opaque</tt></td>
2116 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2117 </tr>
2118</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2119
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2120</div>
2121
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2122
2123
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2124<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2125<h4>
2126 <a name="t_pointer">Pointer Type</a>
2127</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2128
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2129<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2130
2131<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2132<p>The pointer type is used to specify memory locations.
2133 Pointers are commonly used to reference objects in memory.</p>
2134
2135<p>Pointer types may have an optional address space attribute defining the
2136 numbered address space where the pointed-to object resides. The default
2137 address space is number zero. The semantics of non-zero address
2138 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2139
2140<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2141 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2142
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2143<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2144<pre>
2145 &lt;type&gt; *
2146</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2147
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2148<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2149<table class="layout">
2150 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2151 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2152 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2153 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2154 </tr>
2155 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2156 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2157 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2158 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2159 <tt>i32</tt>.</td>
2160 </tr>
2161 <tr class="layout">
2162 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2163 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2164 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2165 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2166</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2167
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2168</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2169
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2170<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2171<h4>
2172 <a name="t_vector">Vector Type</a>
2173</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2174
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2175<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2176
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2177<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2178<p>A vector type is a simple derived type that represents a vector of elements.
2179 Vector types are used when multiple primitive data are operated in parallel
2180 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2181 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2182 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2183
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2184<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2185<pre>
2186 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2187</pre>
2188
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2189<p>The number of elements is a constant integer value larger than 0; elementtype
2190 may be any integer or floating point type. Vectors of size zero are not
2191 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2192
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2193<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2194<table class="layout">
2195 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2196 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2197 <td class="left">Vector of 4 32-bit integer values.</td>
2198 </tr>
2199 <tr class="layout">
2200 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2201 <td class="left">Vector of 8 32-bit floating-point values.</td>
2202 </tr>
2203 <tr class="layout">
2204 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2205 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2206 </tr>
2207</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2208
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2209</div>
2210
Bill Wendlingaf75f0c2011-07-31 06:47:33 +0000[diff] [blame]2211</div>
2212
NAKAMURA Takumi4b2e07a2011-10-31 13:04:26 +0000[diff] [blame]2213</div>
2214
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2215<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2216<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2217<!-- *********************************************************************** -->
2218
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2219<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2220
2221<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2222 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2223
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2224<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2225<h3>
2226 <a name="simpleconstants">Simple Constants</a>
2227</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2228
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2229<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2230
2231<dl>
2232 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2233 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2234 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2235
2236 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2237 <dd>Standard integers (such as '4') are constants of
2238 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2239 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2240
2241 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2242 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2243 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2244 notation (see below). The assembler requires the exact decimal value of a
2245 floating-point constant. For example, the assembler accepts 1.25 but
2246 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2247 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2248
2249 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2250 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2251 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2252</dl>
2253
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2254<p>The one non-intuitive notation for constants is the hexadecimal form of
2255 floating point constants. For example, the form '<tt>double
2256 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2257 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2258 constants are required (and the only time that they are generated by the
2259 disassembler) is when a floating point constant must be emitted but it cannot
2260 be represented as a decimal floating point number in a reasonable number of
2261 digits. For example, NaN's, infinities, and other special values are
2262 represented in their IEEE hexadecimal format so that assembly and disassembly
2263 do not cause any bits to change in the constants.</p>
2264
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2265<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2266 represented using the 16-digit form shown above (which matches the IEEE754
2267 representation for double); float values must, however, be exactly
2268 representable as IEE754 single precision. Hexadecimal format is always used
2269 for long double, and there are three forms of long double. The 80-bit format
2270 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2271 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2272 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2273 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2274 currently supported target uses this format. Long doubles will only work if
2275 they match the long double format on your target. All hexadecimal formats
2276 are big-endian (sign bit at the left).</p>
2277
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2278<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2279</div>
2280
2281<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2282<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2283<a name="aggregateconstants"></a> <!-- old anchor -->
2284<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2285</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2286
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2287<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2288
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2289<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2290 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2291
2292<dl>
2293 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2294 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2295 type definitions (a comma separated list of elements, surrounded by braces
2296 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2297 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2298 Structure constants must have <a href="#t_struct">structure type</a>, and
2299 the number and types of elements must match those specified by the
2300 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2301
2302 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2303 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2304 definitions (a comma separated list of elements, surrounded by square
2305 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2306 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2307 the number and types of elements must match those specified by the
2308 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2309
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2310 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2311 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2312 definitions (a comma separated list of elements, surrounded by
2313 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2314 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2315 have <a href="#t_vector">vector type</a>, and the number and types of
2316 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2317
2318 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2319 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2320 value to zero of <em>any</em> type, including scalar and
2321 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2322 This is often used to avoid having to print large zero initializers
2323 (e.g. for large arrays) and is always exactly equivalent to using explicit
2324 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2325
2326 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2327 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2328 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2329 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2330 be interpreted as part of the instruction stream, metadata is a place to
2331 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2332</dl>
2333
2334</div>
2335
2336<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2337<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2338 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2339</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2340
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2341<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2342
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2343<p>The addresses of <a href="#globalvars">global variables</a>
2344 and <a href="#functionstructure">functions</a> are always implicitly valid
2345 (link-time) constants. These constants are explicitly referenced when
2346 the <a href="#identifiers">identifier for the global</a> is used and always
2347 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2348 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2349
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2350<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2351@X = global i32 17
2352@Y = global i32 42
2353@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2354</pre>
2355
2356</div>
2357
2358<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2359<h3>
2360 <a name="undefvalues">Undefined Values</a>
2361</h3>
2362
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2363<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2364
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2365<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]2366 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2367 Undefined values may be of any type (other than '<tt>label</tt>'
2368 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2369
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2370<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2371 program is well defined no matter what value is used. This gives the
2372 compiler more freedom to optimize. Here are some examples of (potentially
2373 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2374
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2375
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2376<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2377 %A = add %X, undef
2378 %B = sub %X, undef
2379 %C = xor %X, undef
2380Safe:
2381 %A = undef
2382 %B = undef
2383 %C = undef
2384</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2385
2386<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]2387 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]2388
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2389<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2390 %A = or %X, undef
2391 %B = and %X, undef
2392Safe:
2393 %A = -1
2394 %B = 0
2395Unsafe:
2396 %A = undef
2397 %B = undef
2398</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2399
2400<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2401 For example, if <tt>%X</tt> has a zero bit, then the output of the
2402 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2403 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2404 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2405 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2406 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2407 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2408 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2409
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2410<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2411 %A = select undef, %X, %Y
2412 %B = select undef, 42, %Y
2413 %C = select %X, %Y, undef
2414Safe:
2415 %A = %X (or %Y)
2416 %B = 42 (or %Y)
2417 %C = %Y
2418Unsafe:
2419 %A = undef
2420 %B = undef
2421 %C = undef
2422</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2423
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2424<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2425 branch) conditions can go <em>either way</em>, but they have to come from one
2426 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2427 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2428 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2429 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2430 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2431 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2432
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2433<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2434 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2435
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2436 %B = undef
2437 %C = xor %B, %B
2438
2439 %D = undef
2440 %E = icmp lt %D, 4
2441 %F = icmp gte %D, 4
2442
2443Safe:
2444 %A = undef
2445 %B = undef
2446 %C = undef
2447 %D = undef
2448 %E = undef
2449 %F = undef
2450</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2451
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2452<p>This example points out that two '<tt>undef</tt>' operands are not
2453 necessarily the same. This can be surprising to people (and also matches C
2454 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2455 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2456 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2457 its value over its "live range". This is true because the variable doesn't
2458 actually <em>have a live range</em>. Instead, the value is logically read
2459 from arbitrary registers that happen to be around when needed, so the value
2460 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2461 need to have the same semantics or the core LLVM "replace all uses with"
2462 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2463
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2464<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2465 %A = fdiv undef, %X
2466 %B = fdiv %X, undef
2467Safe:
2468 %A = undef
2469b: unreachable
2470</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2471
2472<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2473 value</em> and <em>undefined behavior</em>. An undefined value (like
2474 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2475 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2476 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2477 defined on SNaN's. However, in the second example, we can make a more
2478 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2479 arbitrary value, we are allowed to assume that it could be zero. Since a
2480 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2481 the operation does not execute at all. This allows us to delete the divide and
2482 all code after it. Because the undefined operation "can't happen", the
2483 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2484
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2485<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2486a: store undef -> %X
2487b: store %X -> undef
2488Safe:
2489a: &lt;deleted&gt;
2490b: unreachable
2491</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2492
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2493<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2494 undefined value can be assumed to not have any effect; we can assume that the
2495 value is overwritten with bits that happen to match what was already there.
2496 However, a store <em>to</em> an undefined location could clobber arbitrary
2497 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2498
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2499</div>
2500
2501<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2502<h3>
2503 <a name="trapvalues">Trap Values</a>
2504</h3>
2505
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2506<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2507
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2508<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2509 instead of representing an unspecified bit pattern, they represent the
2510 fact that an instruction or constant expression which cannot evoke side
2511 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2512 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2513
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2514<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]2515 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2516 <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]2517
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2518<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2519
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2520<ul>
2521<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2522 their operands.</li>
2523
2524<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2525 to their dynamic predecessor basic block.</li>
2526
2527<li>Function arguments depend on the corresponding actual argument values in
2528 the dynamic callers of their functions.</li>
2529
2530<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2531 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2532 control back to them.</li>
2533
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2534<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2535 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2536 or exception-throwing call instructions that dynamically transfer control
2537 back to them.</li>
2538
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2539<li>Non-volatile loads and stores depend on the most recent stores to all of the
2540 referenced memory addresses, following the order in the IR
2541 (including loads and stores implied by intrinsics such as
2542 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2543
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2544<!-- TODO: In the case of multiple threads, this only applies if the store
2545 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2546
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2547<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2548
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2549<li>An instruction with externally visible side effects depends on the most
2550 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2551 the order in the IR. (This includes
2552 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2553
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2554<li>An instruction <i>control-depends</i> on a
2555 <a href="#terminators">terminator instruction</a>
2556 if the terminator instruction has multiple successors and the instruction
2557 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2558 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2559
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2560<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2561 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2562 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2563 successor.</li>
2564
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2565<li>Dependence is transitive.</li>
2566
2567</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2568
2569<p>Whenever a trap value is generated, all values which depend on it evaluate
Lang Hames87d5cb82011-10-13 23:04:49 +0000[diff] [blame]2570 to trap. If they have side effects, they evoke their side effects as if each
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2571 operand with a trap value were undef. If they have externally-visible side
2572 effects, the behavior is undefined.</p>
2573
2574<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2575
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2576<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2577entry:
2578 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2579 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2580 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2581 store i32 0, i32* %trap_yet_again ; undefined behavior
2582
2583 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2584 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2585
Chris Lattnerfbe910e2011-11-27 06:56:53 +0000[diff] [blame]2586 store volatile i32 %trap, i32* @g ; External observation; undefined behavior.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2587
2588 %narrowaddr = bitcast i32* @g to i16*
2589 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2590 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2591 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2592
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2593 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2594 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2595
2596true:
Chris Lattnerfbe910e2011-11-27 06:56:53 +0000[diff] [blame]2597 store volatile i32 0, i32* @g ; This is control-dependent on %cmp, so
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2598 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2599 br label %end
2600
2601end:
2602 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2603 ; Both edges into this PHI are
2604 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2605 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2606
Chris Lattnerfbe910e2011-11-27 06:56:53 +0000[diff] [blame]2607 store volatile i32 0, i32* @g ; This would depend on the store in %true
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2608 ; if %cmp is true, or the store in %entry
2609 ; otherwise, so this is undefined behavior.
2610
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2611 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2612 ; The same branch again, but this time the
2613 ; true block doesn't have side effects.
2614
2615second_true:
2616 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2617 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2618
2619second_end:
Chris Lattnerfbe910e2011-11-27 06:56:53 +0000[diff] [blame]2620 store volatile i32 0, i32* @g ; This time, the instruction always depends
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2621 ; on the store in %end. Also, it is
2622 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2623 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2624 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2625</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2626
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2627</div>
2628
2629<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2630<h3>
2631 <a name="blockaddress">Addresses of Basic Blocks</a>
2632</h3>
2633
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2634<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2635
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2636<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2637
2638<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2639 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2640 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2641
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2642<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2643 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2644 comparisons against null. Pointer equality tests between labels addresses
2645 results in undefined behavior &mdash; though, again, comparison against null
2646 is ok, and no label is equal to the null pointer. This may be passed around
2647 as an opaque pointer sized value as long as the bits are not inspected. This
2648 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2649 long as the original value is reconstituted before the <tt>indirectbr</tt>
2650 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2651
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2652<p>Finally, some targets may provide defined semantics when using the value as
2653 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2654
2655</div>
2656
2657
2658<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2659<h3>
2660 <a name="constantexprs">Constant Expressions</a>
2661</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2662
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2663<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2664
2665<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2666 to be used as constants. Constant expressions may be of
2667 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2668 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2669 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2670
2671<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2672 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2673 <dd>Truncate a constant to another type. The bit size of CST must be larger
2674 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2675
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2676 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2677 <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]2678 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2679
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2680 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2681 <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]2682 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2683
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2684 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2685 <dd>Truncate a floating point constant to another floating point type. The
2686 size of CST must be larger than the size of TYPE. Both types must be
2687 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2688
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2689 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2690 <dd>Floating point extend a constant to another type. The size of CST must be
2691 smaller or equal to the size of TYPE. Both types must be floating
2692 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2693
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2694 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2695 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2696 constant. TYPE must be a scalar or vector integer type. CST must be of
2697 scalar or vector floating point type. Both CST and TYPE must be scalars,
2698 or vectors of the same number of elements. If the value won't fit in the
2699 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2700
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2701 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2702 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2703 constant. TYPE must be a scalar or vector integer type. CST must be of
2704 scalar or vector floating point type. Both CST and TYPE must be scalars,
2705 or vectors of the same number of elements. If the value won't fit in the
2706 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2707
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2708 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2709 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2710 constant. TYPE must be a scalar or vector floating point type. CST must be
2711 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2712 vectors of the same number of elements. If the value won't fit in the
2713 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2714
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2715 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2716 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2717 constant. TYPE must be a scalar or vector floating point type. CST must be
2718 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2719 vectors of the same number of elements. If the value won't fit in the
2720 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2721
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2722 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2723 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2724 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2725 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2726 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2727
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2728 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2729 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2730 type. CST must be of integer type. The CST value is zero extended,
2731 truncated, or unchanged to make it fit in a pointer size. This one is
2732 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2733
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2734 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2735 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2736 are the same as those for the <a href="#i_bitcast">bitcast
2737 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2738
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2739 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2740 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2741 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2742 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2743 instruction, the index list may have zero or more indexes, which are
2744 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2745
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2746 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2747 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2748
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2749 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2750 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2751
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2752 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2753 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2754
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2755 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2756 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2757 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2758
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2759 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2760 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2761 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2762
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2763 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2764 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2765 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2766
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2767 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2768 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2769 constants. The index list is interpreted in a similar manner as indices in
2770 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2771 index value must be specified.</dd>
2772
2773 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2774 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2775 constants. The index list is interpreted in a similar manner as indices in
2776 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2777 index value must be specified.</dd>
2778
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2779 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2780 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2781 be any of the <a href="#binaryops">binary</a>
2782 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2783 on operands are the same as those for the corresponding instruction
2784 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2785</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2786
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2787</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2788
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2789</div>
2790
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2791<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2792<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2793<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2794<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2795<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2796<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2797<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2798</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2799
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2800<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2801
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2802<p>LLVM supports inline assembler expressions (as opposed
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2803 to <a href="#moduleasm">Module-Level Inline Assembly</a>) through the use of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2804 a special value. This value represents the inline assembler as a string
2805 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2806 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2807 expression has side effects, and a flag indicating whether the function
2808 containing the asm needs to align its stack conservatively. An example
2809 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2810
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2811<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2812i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2813</pre>
2814
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2815<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2816 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2817 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2818
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2819<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2820%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]2821</pre>
2822
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2823<p>Inline asms with side effects not visible in the constraint list must be
2824 marked as having side effects. This is done through the use of the
2825 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2826
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2827<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2828call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2829</pre>
2830
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2831<p>In some cases inline asms will contain code that will not work unless the
2832 stack is aligned in some way, such as calls or SSE instructions on x86,
2833 yet will not contain code that does that alignment within the asm.
2834 The compiler should make conservative assumptions about what the asm might
2835 contain and should generate its usual stack alignment code in the prologue
2836 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2837
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2838<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2839call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2840</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2841
2842<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2843 first.</p>
2844
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2845<!--
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2846<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2847 documented here. Constraints on what can be done (e.g. duplication, moving,
2848 etc need to be documented). This is probably best done by reference to
2849 another document that covers inline asm from a holistic perspective.</p>
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2850 -->
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2851
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2852<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2853<h4>
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2854 <a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2855</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2856
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2857<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2858
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2859<p>The call instructions that wrap inline asm nodes may have a
2860 "<tt>!srcloc</tt>" MDNode attached to it that contains a list of constant
2861 integers. If present, the code generator will use the integer as the
2862 location cookie value when report errors through the <tt>LLVMContext</tt>
2863 error reporting mechanisms. This allows a front-end to correlate backend
2864 errors that occur with inline asm back to the source code that produced it.
2865 For example:</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2866
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2867<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2868call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2869...
2870!42 = !{ i32 1234567 }
2871</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2872
2873<p>It is up to the front-end to make sense of the magic numbers it places in the
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame^]2874 IR. If the MDNode contains multiple constants, the code generator will use
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2875 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]2876
2877</div>
2878
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2879</div>
2880
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2881<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2882<h3>
2883 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2884</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2885
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2886<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2887
2888<p>LLVM IR allows metadata to be attached to instructions in the program that
2889 can convey extra information about the code to the optimizers and code
2890 generator. One example application of metadata is source-level debug
2891 information. There are two metadata primitives: strings and nodes. All
2892 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2893 preceding exclamation point ('<tt>!</tt>').</p>
2894
2895<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2896 any character by escaping non-printable characters with "<tt>\xx</tt>" where
2897 "<tt>xx</tt>" is the two digit hex code. For example:
2898 "<tt>!"test\00"</tt>".</p>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2899
2900<p>Metadata nodes are represented with notation similar to structure constants
2901 (a comma separated list of elements, surrounded by braces and preceded by an
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2902 exclamation point). Metadata nodes can have any values as their operand. For
2903 example:</p>
2904
2905<div class="doc_code">
2906<pre>
2907!{ metadata !"test\00", i32 10}
2908</pre>
2909</div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2910
2911<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2912 metadata nodes, which can be looked up in the module symbol table. For
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2913 example:</p>
2914
2915<div class="doc_code">
2916<pre>
2917!foo = metadata !{!4, !3}
2918</pre>
2919</div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2920
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2921<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2922 function is using two metadata arguments:</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2923
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2924<div class="doc_code">
2925<pre>
2926call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2927</pre>
2928</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2929
2930<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2931 attached to the <tt>add</tt> instruction using the <tt>!dbg</tt>
2932 identifier:</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2933
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2934<div class="doc_code">
2935<pre>
2936%indvar.next = add i64 %indvar, 1, !dbg !21
2937</pre>
2938</div>
2939
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]2940<p>More information about specific metadata nodes recognized by the optimizers
2941 and code generator is found below.</p>
2942
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2943<!-- _______________________________________________________________________ -->
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]2944<h4>
2945 <a name="tbaa">'<tt>tbaa</tt>' Metadata</a>
2946</h4>
2947
2948<div>
2949
2950<p>In LLVM IR, memory does not have types, so LLVM's own type system is not
2951 suitable for doing TBAA. Instead, metadata is added to the IR to describe
2952 a type system of a higher level language. This can be used to implement
2953 typical C/C++ TBAA, but it can also be used to implement custom alias
2954 analysis behavior for other languages.</p>
2955
2956<p>The current metadata format is very simple. TBAA metadata nodes have up to
2957 three fields, e.g.:</p>
2958
2959<div class="doc_code">
2960<pre>
2961!0 = metadata !{ metadata !"an example type tree" }
2962!1 = metadata !{ metadata !"int", metadata !0 }
2963!2 = metadata !{ metadata !"float", metadata !0 }
2964!3 = metadata !{ metadata !"const float", metadata !2, i64 1 }
2965</pre>
2966</div>
2967
2968<p>The first field is an identity field. It can be any value, usually
2969 a metadata string, which uniquely identifies the type. The most important
2970 name in the tree is the name of the root node. Two trees with
2971 different root node names are entirely disjoint, even if they
2972 have leaves with common names.</p>
2973
2974<p>The second field identifies the type's parent node in the tree, or
2975 is null or omitted for a root node. A type is considered to alias
2976 all of its descendants and all of its ancestors in the tree. Also,
2977 a type is considered to alias all types in other trees, so that
2978 bitcode produced from multiple front-ends is handled conservatively.</p>
2979
2980<p>If the third field is present, it's an integer which if equal to 1
2981 indicates that the type is "constant" (meaning
2982 <tt>pointsToConstantMemory</tt> should return true; see
2983 <a href="AliasAnalysis.html#OtherItfs">other useful
2984 <tt>AliasAnalysis</tt> methods</a>).</p>
2985
2986</div>
2987
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2988<!-- _______________________________________________________________________ -->
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]2989<h4>
2990 <a name="fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a>
2991</h4>
2992
2993<div>
2994
2995<p><tt>fpaccuracy</tt> metadata may be attached to any instruction of floating
2996 point type. It expresses the maximum relative error of the result of
2997 that instruction, in ULPs. ULP is defined as follows:</p>
2998
Bill Wendling0656e252011-11-09 19:33:56 +0000[diff] [blame]2999<blockquote>
3000
3001<p>If <tt>x</tt> is a real number that lies between two finite consecutive
3002 floating-point numbers <tt>a</tt> and <tt>b</tt>, without being equal to one
3003 of them, then <tt>ulp(x) = |b - a|</tt>, otherwise <tt>ulp(x)</tt> is the
3004 distance between the two non-equal finite floating-point numbers nearest
3005 <tt>x</tt>. Moreover, <tt>ulp(NaN)</tt> is <tt>NaN</tt>.</p>
3006
3007</blockquote>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3008
3009<p>The maximum relative error may be any rational number. The metadata node
3010 shall consist of a pair of unsigned integers respectively representing
3011 the numerator and denominator. For example, 2.5 ULP:</p>
3012
3013<div class="doc_code">
3014<pre>
3015!0 = metadata !{ i32 5, i32 2 }
3016</pre>
3017</div>
3018
3019</div>
3020
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]3021</div>
3022
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3023</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3024
3025<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3026<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3027 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3028</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3029<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3030<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3031<p>LLVM has a number of "magic" global variables that contain data that affect
3032code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3033of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
3034section and all globals that start with "<tt>llvm.</tt>" are reserved for use
3035by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3036
3037<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3038<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3039<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3040</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3041
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3042<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3043
3044<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
3045href="#linkage_appending">appending linkage</a>. This array contains a list of
3046pointers to global variables and functions which may optionally have a pointer
3047cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
3048
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3049<div class="doc_code">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3050<pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3051@X = global i8 4
3052@Y = global i32 123
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3053
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3054@llvm.used = appending global [2 x i8*] [
3055 i8* @X,
3056 i8* bitcast (i32* @Y to i8*)
3057], section "llvm.metadata"
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3058</pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3059</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3060
3061<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3062 compiler, assembler, and linker are required to treat the symbol as if there
3063 is a reference to the global that it cannot see. For example, if a variable
3064 has internal linkage and no references other than that from
3065 the <tt>@llvm.used</tt> list, it cannot be deleted. This is commonly used to
3066 represent references from inline asms and other things the compiler cannot
3067 "see", and corresponds to "<tt>attribute((used))</tt>" in GNU C.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3068
3069<p>On some targets, the code generator must emit a directive to the assembler or
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3070 object file to prevent the assembler and linker from molesting the
3071 symbol.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3072
3073</div>
3074
3075<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3076<h3>
3077 <a name="intg_compiler_used">
3078 The '<tt>llvm.compiler.used</tt>' Global Variable
3079 </a>
3080</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3081
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3082<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3083
3084<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3085 <tt>@llvm.used</tt> directive, except that it only prevents the compiler from
3086 touching the symbol. On targets that support it, this allows an intelligent
3087 linker to optimize references to the symbol without being impeded as it would
3088 be by <tt>@llvm.used</tt>.</p>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3089
3090<p>This is a rare construct that should only be used in rare circumstances, and
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3091 should not be exposed to source languages.</p>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3092
3093</div>
3094
3095<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3096<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3097<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3098</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3099
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3100<div>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3101
3102<div class="doc_code">
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3103<pre>
3104%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]3105@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3106</pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3107</div>
3108
3109<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor
3110 functions and associated priorities. The functions referenced by this array
3111 will be called in ascending order of priority (i.e. lowest first) when the
3112 module is loaded. The order of functions with the same priority is not
3113 defined.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3114
3115</div>
3116
3117<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3118<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3119<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3120</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3121
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3122<div>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3123
3124<div class="doc_code">
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3125<pre>
3126%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]3127@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3128</pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3129</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3130
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3131<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions
3132 and associated priorities. The functions referenced by this array will be
3133 called in descending order of priority (i.e. highest first) when the module
3134 is loaded. The order of functions with the same priority is not defined.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3135
3136</div>
3137
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3138</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3139
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]3140<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3141<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3142<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3143
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3144<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3145
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3146<p>The LLVM instruction set consists of several different classifications of
3147 instructions: <a href="#terminators">terminator
3148 instructions</a>, <a href="#binaryops">binary instructions</a>,
3149 <a href="#bitwiseops">bitwise binary instructions</a>,
3150 <a href="#memoryops">memory instructions</a>, and
3151 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3152
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3153<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3154<h3>
3155 <a name="terminators">Terminator Instructions</a>
3156</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3157
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3158<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3159
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3160<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3161 in a program ends with a "Terminator" instruction, which indicates which
3162 block should be executed after the current block is finished. These
3163 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3164 control flow, not values (the one exception being the
3165 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3166
Chris Lattner6445ecb2011-08-02 20:29:13 +0000[diff] [blame]3167<p>The terminator instructions are:
3168 '<a href="#i_ret"><tt>ret</tt></a>',
3169 '<a href="#i_br"><tt>br</tt></a>',
3170 '<a href="#i_switch"><tt>switch</tt></a>',
3171 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3172 '<a href="#i_invoke"><tt>invoke</tt></a>',
3173 '<a href="#i_unwind"><tt>unwind</tt></a>',
3174 '<a href="#i_resume"><tt>resume</tt></a>', and
3175 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3176
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3177<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3178<h4>
3179 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3180</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3181
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3182<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3183
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3184<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3185<pre>
3186 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]3187 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3188</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3189
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3190<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3191<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3192 a value) from a function back to the caller.</p>
3193
3194<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3195 value and then causes control flow, and one that just causes control flow to
3196 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3197
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3199<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3200 return value. The type of the return value must be a
3201 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3202
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3203<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3204 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3205 value or a return value with a type that does not match its type, or if it
3206 has a void return type and contains a '<tt>ret</tt>' instruction with a
3207 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3208
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3209<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3210<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3211 the calling function's context. If the caller is a
3212 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3213 instruction after the call. If the caller was an
3214 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3215 the beginning of the "normal" destination block. If the instruction returns
3216 a value, that value shall set the call or invoke instruction's return
3217 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3219<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3220<pre>
3221 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3222 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3223 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]3224</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3225
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3226</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3227<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3228<h4>
3229 <a name="i_br">'<tt>br</tt>' Instruction</a>
3230</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3231
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3232<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3233
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3234<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3235<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3236 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3237 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3238</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3239
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3240<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3241<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3242 different basic block in the current function. There are two forms of this
3243 instruction, corresponding to a conditional branch and an unconditional
3244 branch.</p>
3245
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3246<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3247<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3248 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3249 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3250 target.</p>
3251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3252<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3253<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3254 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3255 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3256 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3257
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3258<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3259<pre>
3260Test:
3261 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3262 br i1 %cond, label %IfEqual, label %IfUnequal
3263IfEqual:
3264 <a href="#i_ret">ret</a> i32 1
3265IfUnequal:
3266 <a href="#i_ret">ret</a> i32 0
3267</pre>
3268
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3269</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3270
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3271<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3272<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3273 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3274</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3275
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3276<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3277
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3278<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3279<pre>
3280 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3281</pre>
3282
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3283<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3284<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]3285 several different places. It is a generalization of the '<tt>br</tt>'
3286 instruction, allowing a branch to occur to one of many possible
3287 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3288
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3289<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3290<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3291 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3292 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3293 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3294
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3295<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3296<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3297 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3298 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3299 transferred to the corresponding destination; otherwise, control flow is
3300 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3301
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3302<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3303<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3304 <tt>switch</tt> instruction, this instruction may be code generated in
3305 different ways. For example, it could be generated as a series of chained
3306 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3307
3308<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3309<pre>
3310 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3311 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3312 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3313
3314 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3315 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3316
3317 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3318 switch i32 %val, label %otherwise [ i32 0, label %onzero
3319 i32 1, label %onone
3320 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3321</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3322
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3323</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3324
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3325
3326<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3327<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3328 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3329</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3330
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3331<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3332
3333<h5>Syntax:</h5>
3334<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3335 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]3336</pre>
3337
3338<h5>Overview:</h5>
3339
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3340<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3341 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3342 "<tt>address</tt>". Address must be derived from a <a
3343 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3344
3345<h5>Arguments:</h5>
3346
3347<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3348 rest of the arguments indicate the full set of possible destinations that the
3349 address may point to. Blocks are allowed to occur multiple times in the
3350 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3351
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3352<p>This destination list is required so that dataflow analysis has an accurate
3353 understanding of the CFG.</p>
3354
3355<h5>Semantics:</h5>
3356
3357<p>Control transfers to the block specified in the address argument. All
3358 possible destination blocks must be listed in the label list, otherwise this
3359 instruction has undefined behavior. This implies that jumps to labels
3360 defined in other functions have undefined behavior as well.</p>
3361
3362<h5>Implementation:</h5>
3363
3364<p>This is typically implemented with a jump through a register.</p>
3365
3366<h5>Example:</h5>
3367<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3368 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3369</pre>
3370
3371</div>
3372
3373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3374<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3375<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3376 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3377</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3378
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3379<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3382<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3383 &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]3384 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3385</pre>
3386
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3387<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3388<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3389 function, with the possibility of control flow transfer to either the
3390 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3391 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3392 control flow will return to the "normal" label. If the callee (or any
3393 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3394 instruction, control is interrupted and continued at the dynamically nearest
3395 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3396
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3397<p>The '<tt>exception</tt>' label is a
3398 <i><a href="ExceptionHandling.html#overview">landing pad</a></i> for the
3399 exception. As such, '<tt>exception</tt>' label is required to have the
3400 "<a href="#i_landingpad"><tt>landingpad</tt></a>" instruction, which contains
3401 the information about about the behavior of the program after unwinding
3402 happens, as its first non-PHI instruction. The restrictions on the
3403 "<tt>landingpad</tt>" instruction's tightly couples it to the
3404 "<tt>invoke</tt>" instruction, so that the important information contained
3405 within the "<tt>landingpad</tt>" instruction can't be lost through normal
3406 code motion.</p>
3407
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3408<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3409<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3410
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3411<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3412 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3413 convention</a> the call should use. If none is specified, the call
3414 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3415
3416 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3417 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3418 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3419
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3420 <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]3421 function value being invoked. In most cases, this is a direct function
3422 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3423 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3424
3425 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3426 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3427
3428 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3429 signature argument types and parameter attributes. All arguments must be
3430 of <a href="#t_firstclass">first class</a> type. If the function
3431 signature indicates the function accepts a variable number of arguments,
3432 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3433
3434 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3435 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3436
3437 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3438 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3439
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3440 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3441 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3442 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3443</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3444
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3445<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3446<p>This instruction is designed to operate as a standard
3447 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3448 primary difference is that it establishes an association with a label, which
3449 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3450
3451<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3452 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3453 exception. Additionally, this is important for implementation of
3454 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3455
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3456<p>For the purposes of the SSA form, the definition of the value returned by the
3457 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3458 block to the "normal" label. If the callee unwinds then no return value is
3459 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3460
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3461<p>Note that the code generator does not yet completely support unwind, and
3462that the invoke/unwind semantics are likely to change in future versions.</p>
3463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3464<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3465<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3466 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3467 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3468 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3469 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3470</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3471
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3472</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3473
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3474<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3475
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3476<h4>
3477 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3478</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3480<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3481
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3482<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3483<pre>
3484 unwind
3485</pre>
3486
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3487<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3488<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489 at the first callee in the dynamic call stack which used
3490 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3491 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3492
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3493<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3494<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3495 immediately halt. The dynamic call stack is then searched for the
3496 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3497 Once found, execution continues at the "exceptional" destination block
3498 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3499 instruction in the dynamic call chain, undefined behavior results.</p>
3500
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3501<p>Note that the code generator does not yet completely support unwind, and
3502that the invoke/unwind semantics are likely to change in future versions.</p>
3503
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3504</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3505
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3506 <!-- _______________________________________________________________________ -->
3507
3508<h4>
3509 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3510</h4>
3511
3512<div>
3513
3514<h5>Syntax:</h5>
3515<pre>
3516 resume &lt;type&gt; &lt;value&gt;
3517</pre>
3518
3519<h5>Overview:</h5>
3520<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3521 successors.</p>
3522
3523<h5>Arguments:</h5>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3524<p>The '<tt>resume</tt>' instruction requires one argument, which must have the
Bill Wendlinge4ad50b2011-08-03 18:37:32 +0000[diff] [blame]3525 same type as the result of any '<tt>landingpad</tt>' instruction in the same
3526 function.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3527
3528<h5>Semantics:</h5>
3529<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3530 (in-flight) exception whose unwinding was interrupted with
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3531 a <a href="#i_landingpad"><tt>landingpad</tt></a> instruction.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3532
3533<h5>Example:</h5>
3534<pre>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3535 resume { i8*, i32 } %exn
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3536</pre>
3537
3538</div>
3539
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3540<!-- _______________________________________________________________________ -->
3541
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3542<h4>
3543 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3544</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3545
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3546<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3547
3548<h5>Syntax:</h5>
3549<pre>
3550 unreachable
3551</pre>
3552
3553<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3554<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3555 instruction is used to inform the optimizer that a particular portion of the
3556 code is not reachable. This can be used to indicate that the code after a
3557 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3558
3559<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3560<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3561
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3562</div>
3563
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3564</div>
3565
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3566<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3567<h3>
3568 <a name="binaryops">Binary Operations</a>
3569</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3570
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3571<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3572
3573<p>Binary operators are used to do most of the computation in a program. They
3574 require two operands of the same type, execute an operation on them, and
3575 produce a single value. The operands might represent multiple data, as is
3576 the case with the <a href="#t_vector">vector</a> data type. The result value
3577 has the same type as its operands.</p>
3578
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3579<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3580
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3581<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3582<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3583 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3584</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3585
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3586<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3587
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3588<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3589<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3590 &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]3591 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3592 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3593 &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]3594</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3595
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3596<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3597<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3598
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3599<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600<p>The two arguments to the '<tt>add</tt>' instruction must
3601 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3602 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3603
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3604<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3605<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3606
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3607<p>If the sum has unsigned overflow, the result returned is the mathematical
3608 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]3609
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610<p>Because LLVM integers use a two's complement representation, this instruction
3611 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3612
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3613<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3614 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3615 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3616 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3617 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3618
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3619<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3620<pre>
3621 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3622</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3623
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3624</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3625
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3626<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3627<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3628 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3629</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3630
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3631<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3632
3633<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3634<pre>
3635 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3636</pre>
3637
3638<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3639<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3640
3641<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3642<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3643 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3644 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3645
3646<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3647<p>The value produced is the floating point sum of the two operands.</p>
3648
3649<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3650<pre>
3651 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3652</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3653
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3654</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3655
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3656<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3657<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3658 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3659</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3660
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3661<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3663<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3664<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3665 &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]3666 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3667 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3668 &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]3669</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3671<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3672<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3674
3675<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3676 '<tt>neg</tt>' instruction present in most other intermediate
3677 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3678
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3679<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680<p>The two arguments to the '<tt>sub</tt>' instruction must
3681 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3682 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3683
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3684<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3685<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3686
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3687<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3688 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3689 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3690
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3691<p>Because LLVM integers use a two's complement representation, this instruction
3692 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3693
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3694<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3695 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3696 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3697 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3698 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3699
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3700<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3701<pre>
3702 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3703 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3704</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3705
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3706</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3707
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3708<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3709<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3710 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3711</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3712
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3713<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3714
3715<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3716<pre>
3717 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3718</pre>
3719
3720<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3721<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3722 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3723
3724<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3725 '<tt>fneg</tt>' instruction present in most other intermediate
3726 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3727
3728<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3729<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3730 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3731 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3732
3733<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3734<p>The value produced is the floating point difference of the two operands.</p>
3735
3736<h5>Example:</h5>
3737<pre>
3738 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3739 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3740</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3741
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3742</div>
3743
3744<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3745<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3746 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3747</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3748
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3749<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3750
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3751<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3752<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3753 &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]3754 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3755 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3756 &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]3757</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3758
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3759<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3760<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3761
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3762<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3763<p>The two arguments to the '<tt>mul</tt>' instruction must
3764 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3765 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3766
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3767<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3768<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3769
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770<p>If the result of the multiplication has unsigned overflow, the result
3771 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3772 width of the result.</p>
3773
3774<p>Because LLVM integers use a two's complement representation, and the result
3775 is the same width as the operands, this instruction returns the correct
3776 result for both signed and unsigned integers. If a full product
3777 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3778 be sign-extended or zero-extended as appropriate to the width of the full
3779 product.</p>
3780
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3781<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3782 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3783 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3784 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3785 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3787<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788<pre>
3789 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3790</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3791
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3792</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3793
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3794<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3795<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3796 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3797</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3798
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3799<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3800
3801<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802<pre>
3803 &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]3804</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3805
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3806<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3807<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3808
3809<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3810<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3811 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3812 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3813
3814<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3815<p>The value produced is the floating point product of the two operands.</p>
3816
3817<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3818<pre>
3819 &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]3820</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3821
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3822</div>
3823
3824<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3825<h4>
3826 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3827</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3828
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3829<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3830
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3831<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3832<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3833 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3834 &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]3835</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3836
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3837<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3838<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3839
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3840<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3841<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3842 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3843 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3844
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3845<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3846<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3847
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3848<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3849 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3850
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3851<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3852
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3853<p>If the <tt>exact</tt> keyword is present, the result value of the
3854 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3855 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3856
3857
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3858<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3859<pre>
3860 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3861</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3862
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3863</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3864
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3865<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3866<h4>
3867 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3868</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3869
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3870<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3871
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3872<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3873<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3874 &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]3875 &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]3876</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3877
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3878<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3879<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3880
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3881<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3882<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3883 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3884 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3885
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3886<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3887<p>The value produced is the signed integer quotient of the two operands rounded
3888 towards zero.</p>
3889
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3890<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3891 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3892
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3893<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3894 undefined behavior; this is a rare case, but can occur, for example, by doing
3895 a 32-bit division of -2147483648 by -1.</p>
3896
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3897<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3898 <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]3899 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3900
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3901<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3902<pre>
3903 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3904</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3905
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3906</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3907
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3908<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3909<h4>
3910 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3911</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3912
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3913<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3915<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3916<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3917 &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]3918</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3919
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3920<h5>Overview:</h5>
3921<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3922
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3923<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3924<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3925 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3926 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3927
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3928<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3929<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3930
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3931<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3932<pre>
3933 &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]3934</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3935
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3936</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3937
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3938<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3939<h4>
3940 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3941</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3942
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3943<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3944
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3945<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3946<pre>
3947 &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]3948</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3949
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3950<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3951<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3952 division of its two arguments.</p>
3953
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3954<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3955<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3956 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3957 values. Both arguments must have identical types.</p>
3958
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3959<h5>Semantics:</h5>
3960<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3961 This instruction always performs an unsigned division to get the
3962 remainder.</p>
3963
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3964<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3965 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3966
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3967<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3968
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3969<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3970<pre>
3971 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3972</pre>
3973
3974</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3975
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3976<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3977<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3978 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3979</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3980
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3981<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3982
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3983<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3984<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3985 &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]3986</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3987
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3988<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3989<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3990 division of its two operands. This instruction can also take
3991 <a href="#t_vector">vector</a> versions of the values in which case the
3992 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3993
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3994<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3995<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3996 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3997 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3998
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3999<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4000<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]4001 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
4002 <i>modulo</i> operator (where the result is either zero or has the same sign
4003 as the divisor, <tt>op2</tt>) of a value.
4004 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4005 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
4006 Math Forum</a>. For a table of how this is implemented in various languages,
4007 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
4008 Wikipedia: modulo operation</a>.</p>
4009
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4010<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4011 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
4012
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4013<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4014 Overflow also leads to undefined behavior; this is a rare case, but can
4015 occur, for example, by taking the remainder of a 32-bit division of
4016 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
4017 lets srem be implemented using instructions that return both the result of
4018 the division and the remainder.)</p>
4019
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4020<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4021<pre>
4022 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4023</pre>
4024
4025</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4026
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4027<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4028<h4>
4029 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
4030</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4031
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4032<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4033
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4034<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4035<pre>
4036 &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]4037</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4038
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4039<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4040<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
4041 its two operands.</p>
4042
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4043<h5>Arguments:</h5>
4044<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4046 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4047
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4048<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4049<p>This instruction returns the <i>remainder</i> of a division. The remainder
4050 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4051
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4052<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4053<pre>
4054 &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]4055</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4056
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4057</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]4058
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4059</div>
4060
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4061<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4062<h3>
4063 <a name="bitwiseops">Bitwise Binary Operations</a>
4064</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4065
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4066<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4067
4068<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
4069 program. They are generally very efficient instructions and can commonly be
4070 strength reduced from other instructions. They require two operands of the
4071 same type, execute an operation on them, and produce a single value. The
4072 resulting value is the same type as its operands.</p>
4073
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4074<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4075<h4>
4076 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
4077</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4078
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4079<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4080
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4081<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4082<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4083 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4084 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4085 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4086 &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]4087</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4088
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4089<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4090<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
4091 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4092
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4093<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4094<p>Both arguments to the '<tt>shl</tt>' instruction must be the
4095 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
4096 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4097
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4098<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4099<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
4100 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
4101 is (statically or dynamically) negative or equal to or larger than the number
4102 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4103 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4104 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4105
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4106<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
4107 <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]4108 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4109 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
4110 with the resultant sign bit. As such, NUW/NSW have the same semantics as
4111 they would if the shift were expressed as a mul instruction with the same
4112 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
4113
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4114<h5>Example:</h5>
4115<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4116 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
4117 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
4118 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4119 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4120 &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]4121</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4122
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4123</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4124
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4125<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4126<h4>
4127 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
4128</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4129
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4130<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4131
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4132<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4133<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4134 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4135 &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]4136</pre>
4137
4138<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4139<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
4140 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4141
4142<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4143<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4144 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4145 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4146
4147<h5>Semantics:</h5>
4148<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4149 significant bits of the result will be filled with zero bits after the shift.
4150 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4151 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4152 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4153 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4154
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4155<p>If the <tt>exact</tt> keyword is present, the result value of the
4156 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4157 shifted out are non-zero.</p>
4158
4159
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4160<h5>Example:</h5>
4161<pre>
4162 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4163 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4164 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4165 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4166 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4167 &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]4168</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4169
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4170</div>
4171
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4172<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4173<h4>
4174 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4175</h4>
4176
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4177<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4178
4179<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4180<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4181 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4182 &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]4183</pre>
4184
4185<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4186<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4187 operand shifted to the right a specified number of bits with sign
4188 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4189
4190<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4191<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4192 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4193 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4194
4195<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4196<p>This instruction always performs an arithmetic shift right operation, The
4197 most significant bits of the result will be filled with the sign bit
4198 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4199 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4200 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4201 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4202
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4203<p>If the <tt>exact</tt> keyword is present, the result value of the
4204 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4205 shifted out are non-zero.</p>
4206
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4207<h5>Example:</h5>
4208<pre>
4209 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4210 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4211 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4212 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4213 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4214 &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]4215</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4216
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4217</div>
4218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4219<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4220<h4>
4221 <a name="i_and">'<tt>and</tt>' Instruction</a>
4222</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4223
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4224<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4225
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4226<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4227<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4228 &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]4229</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4230
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4231<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4232<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4233 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4235<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4236<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4237 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4238 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4239
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4240<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4241<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4242
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4243<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4244 <tbody>
4245 <tr>
4246 <td>In0</td>
4247 <td>In1</td>
4248 <td>Out</td>
4249 </tr>
4250 <tr>
4251 <td>0</td>
4252 <td>0</td>
4253 <td>0</td>
4254 </tr>
4255 <tr>
4256 <td>0</td>
4257 <td>1</td>
4258 <td>0</td>
4259 </tr>
4260 <tr>
4261 <td>1</td>
4262 <td>0</td>
4263 <td>0</td>
4264 </tr>
4265 <tr>
4266 <td>1</td>
4267 <td>1</td>
4268 <td>1</td>
4269 </tr>
4270 </tbody>
4271</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4272
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4273<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4274<pre>
4275 &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]4276 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4277 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4278</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4279</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4280<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4281<h4>
4282 <a name="i_or">'<tt>or</tt>' Instruction</a>
4283</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4284
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4285<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4286
4287<h5>Syntax:</h5>
4288<pre>
4289 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4290</pre>
4291
4292<h5>Overview:</h5>
4293<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4294 two operands.</p>
4295
4296<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4297<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4298 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4299 values. Both arguments must have identical types.</p>
4300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4301<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4302<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4303
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4304<table border="1" cellspacing="0" cellpadding="4">
4305 <tbody>
4306 <tr>
4307 <td>In0</td>
4308 <td>In1</td>
4309 <td>Out</td>
4310 </tr>
4311 <tr>
4312 <td>0</td>
4313 <td>0</td>
4314 <td>0</td>
4315 </tr>
4316 <tr>
4317 <td>0</td>
4318 <td>1</td>
4319 <td>1</td>
4320 </tr>
4321 <tr>
4322 <td>1</td>
4323 <td>0</td>
4324 <td>1</td>
4325 </tr>
4326 <tr>
4327 <td>1</td>
4328 <td>1</td>
4329 <td>1</td>
4330 </tr>
4331 </tbody>
4332</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4333
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4334<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4335<pre>
4336 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4337 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4338 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4339</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4340
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4341</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4342
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4343<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4344<h4>
4345 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4346</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4347
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4348<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4349
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4350<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4351<pre>
4352 &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]4353</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4354
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4355<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4356<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4357 its two operands. The <tt>xor</tt> is used to implement the "one's
4358 complement" operation, which is the "~" operator in C.</p>
4359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4360<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4361<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4362 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4363 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4365<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4366<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4367
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4368<table border="1" cellspacing="0" cellpadding="4">
4369 <tbody>
4370 <tr>
4371 <td>In0</td>
4372 <td>In1</td>
4373 <td>Out</td>
4374 </tr>
4375 <tr>
4376 <td>0</td>
4377 <td>0</td>
4378 <td>0</td>
4379 </tr>
4380 <tr>
4381 <td>0</td>
4382 <td>1</td>
4383 <td>1</td>
4384 </tr>
4385 <tr>
4386 <td>1</td>
4387 <td>0</td>
4388 <td>1</td>
4389 </tr>
4390 <tr>
4391 <td>1</td>
4392 <td>1</td>
4393 <td>0</td>
4394 </tr>
4395 </tbody>
4396</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4398<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4399<pre>
4400 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4401 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4402 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4403 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4404</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4405
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4406</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4407
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4408</div>
4409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4410<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4411<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4412 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4413</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4415<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4416
4417<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4418 target-independent manner. These instructions cover the element-access and
4419 vector-specific operations needed to process vectors effectively. While LLVM
4420 does directly support these vector operations, many sophisticated algorithms
4421 will want to use target-specific intrinsics to take full advantage of a
4422 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4423
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4424<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4425<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4426 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4427</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4428
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4429<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4430
4431<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4432<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4433 &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]4434</pre>
4435
4436<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4437<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4438 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4439
4440
4441<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4442<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4443 of <a href="#t_vector">vector</a> type. The second operand is an index
4444 indicating the position from which to extract the element. The index may be
4445 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4446
4447<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4448<p>The result is a scalar of the same type as the element type of
4449 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4450 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4451 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4452
4453<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4454<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4455 &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]4456</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4457
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4458</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4459
4460<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4461<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4462 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4463</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4464
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4465<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4466
4467<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4468<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4469 &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]4470</pre>
4471
4472<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4473<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4474 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4475
4476<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4477<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4478 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4479 whose type must equal the element type of the first operand. The third
4480 operand is an index indicating the position at which to insert the value.
4481 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4482
4483<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4484<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4485 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4486 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4487 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4488
4489<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4490<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4491 &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]4492</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4493
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4494</div>
4495
4496<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4497<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4498 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4499</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4500
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4501<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4502
4503<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4504<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4505 &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]4506</pre>
4507
4508<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4509<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4510 from two input vectors, returning a vector with the same element type as the
4511 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4512
4513<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4514<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4515 with types that match each other. The third argument is a shuffle mask whose
4516 element type is always 'i32'. The result of the instruction is a vector
4517 whose length is the same as the shuffle mask and whose element type is the
4518 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4519
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4520<p>The shuffle mask operand is required to be a constant vector with either
4521 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4522
4523<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4524<p>The elements of the two input vectors are numbered from left to right across
4525 both of the vectors. The shuffle mask operand specifies, for each element of
4526 the result vector, which element of the two input vectors the result element
4527 gets. The element selector may be undef (meaning "don't care") and the
4528 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4529
4530<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4531<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4532 &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]4533 &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]4534 &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]4535 &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]4536 &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]4537 &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]4538 &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]4539 &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]4540</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4541
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4542</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4543
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4544</div>
4545
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4546<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4547<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4548 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4549</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4550
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4551<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4552
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4553<p>LLVM supports several instructions for working with
4554 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4555
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4556<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4557<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4558 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4559</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4560
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4561<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4562
4563<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4564<pre>
4565 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4566</pre>
4567
4568<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4569<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4570 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4571
4572<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4573<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4574 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4575 <a href="#t_array">array</a> type. The operands are constant indices to
4576 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4577 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4578 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4579 <ul>
4580 <li>Since the value being indexed is not a pointer, the first index is
4581 omitted and assumed to be zero.</li>
4582 <li>At least one index must be specified.</li>
4583 <li>Not only struct indices but also array indices must be in
4584 bounds.</li>
4585 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4586
4587<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4588<p>The result is the value at the position in the aggregate specified by the
4589 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4590
4591<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4592<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4593 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4594</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4595
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4596</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4597
4598<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4599<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4600 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4601</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4602
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4603<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4604
4605<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4606<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4607 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, &lt;idx&gt;}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4608</pre>
4609
4610<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4611<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4612 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4613
4614<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4615<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4616 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4617 <a href="#t_array">array</a> type. The second operand is a first-class
4618 value to insert. The following operands are constant indices indicating
4619 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]4620 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621 value to insert must have the same type as the value identified by the
4622 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4623
4624<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4625<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4626 that of <tt>val</tt> except that the value at the position specified by the
4627 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4628
4629<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4630<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4631 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4632 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4633 %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]4634</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4635
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4636</div>
4637
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4638</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4639
4640<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4641<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4642 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4643</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4644
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4645<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4646
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4647<p>A key design point of an SSA-based representation is how it represents
4648 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4649 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4650 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4651
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4652<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4653<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4654 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4655</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4656
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4657<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4659<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4660<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4661 &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]4662</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4664<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4665<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4666 currently executing function, to be automatically released when this function
4667 returns to its caller. The object is always allocated in the generic address
4668 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4669
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4670<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4671<p>The '<tt>alloca</tt>' instruction
4672 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4673 runtime stack, returning a pointer of the appropriate type to the program.
4674 If "NumElements" is specified, it is the number of elements allocated,
4675 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4676 specified, the value result of the allocation is guaranteed to be aligned to
4677 at least that boundary. If not specified, or if zero, the target can choose
4678 to align the allocation on any convenient boundary compatible with the
4679 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4680
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4681<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4682
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4683<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4684<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4685 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4686 memory is automatically released when the function returns. The
4687 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4688 variables that must have an address available. When the function returns
4689 (either with the <tt><a href="#i_ret">ret</a></tt>
4690 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4691 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4692
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4693<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4694<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4695 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4696 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4697 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4698 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4699</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4700
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4701</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4702
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4703<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4704<h4>
4705 <a name="i_load">'<tt>load</tt>' Instruction</a>
4706</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4707
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4708<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4709
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4710<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4711<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4712 &lt;result&gt; = load [volatile] &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4713 &lt;result&gt; = load atomic [volatile] &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt;
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4714 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4715</pre>
4716
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4717<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4718<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4719
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4720<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4721<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4722 from which to load. The pointer must point to
4723 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4724 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4725 number or order of execution of this <tt>load</tt> with other <a
4726 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4727
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4728<p>If the <code>load</code> is marked as <code>atomic</code>, it takes an extra
4729 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4730 argument. The <code>release</code> and <code>acq_rel</code> orderings are
4731 not valid on <code>load</code> instructions. Atomic loads produce <a
4732 href="#memorymodel">defined</a> results when they may see multiple atomic
4733 stores. The type of the pointee must be an integer type whose bit width
4734 is a power of two greater than or equal to eight and less than or equal
4735 to a target-specific size limit. <code>align</code> must be explicitly
4736 specified on atomic loads, and the load has undefined behavior if the
4737 alignment is not set to a value which is at least the size in bytes of
4738 the pointee. <code>!nontemporal</code> does not have any defined semantics
4739 for atomic loads.</p>
4740
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4741<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4742 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]4743 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4744 alignment for the target. It is the responsibility of the code emitter to
4745 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4746 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4747 produce less efficient code. An alignment of 1 is always safe.</p>
4748
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4749<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4750 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4751 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4752 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4753 and code generator that this load is not expected to be reused in the cache.
4754 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4755 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4756
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4757<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4758<p>The location of memory pointed to is loaded. If the value being loaded is of
4759 scalar type then the number of bytes read does not exceed the minimum number
4760 of bytes needed to hold all bits of the type. For example, loading an
4761 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4762 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4763 is undefined if the value was not originally written using a store of the
4764 same type.</p>
4765
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4766<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4767<pre>
4768 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4769 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4770 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4771</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4772
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4773</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4774
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4775<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4776<h4>
4777 <a name="i_store">'<tt>store</tt>' Instruction</a>
4778</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4779
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4780<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4781
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4782<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4783<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4784 store [volatile] &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4785 store atomic [volatile] &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt; <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4786</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4787
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4788<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4789<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4790
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4791<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4792<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4793 and an address at which to store it. The type of the
4794 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4795 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4796 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4797 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4798 order of execution of this <tt>store</tt> with other <a
4799 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4800
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4801<p>If the <code>store</code> is marked as <code>atomic</code>, it takes an extra
4802 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4803 argument. The <code>acquire</code> and <code>acq_rel</code> orderings aren't
4804 valid on <code>store</code> instructions. Atomic loads produce <a
4805 href="#memorymodel">defined</a> results when they may see multiple atomic
4806 stores. The type of the pointee must be an integer type whose bit width
4807 is a power of two greater than or equal to eight and less than or equal
4808 to a target-specific size limit. <code>align</code> must be explicitly
4809 specified on atomic stores, and the store has undefined behavior if the
4810 alignment is not set to a value which is at least the size in bytes of
4811 the pointee. <code>!nontemporal</code> does not have any defined semantics
4812 for atomic stores.</p>
4813
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4814<p>The optional constant "align" argument specifies the alignment of the
4815 operation (that is, the alignment of the memory address). A value of 0 or an
4816 omitted "align" argument means that the operation has the preferential
4817 alignment for the target. It is the responsibility of the code emitter to
4818 ensure that the alignment information is correct. Overestimating the
4819 alignment results in an undefined behavior. Underestimating the alignment may
4820 produce less efficient code. An alignment of 1 is always safe.</p>
4821
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4822<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4823 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4824 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4825 instruction tells the optimizer and code generator that this load is
4826 not expected to be reused in the cache. The code generator may
4827 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4828 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4829
4830
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4831<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4832<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4833 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4834 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4835 does not exceed the minimum number of bytes needed to hold all bits of the
4836 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4837 writing a value of a type like <tt>i20</tt> with a size that is not an
4838 integral number of bytes, it is unspecified what happens to the extra bits
4839 that do not belong to the type, but they will typically be overwritten.</p>
4840
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4841<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4842<pre>
4843 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4844 store i32 3, i32* %ptr <i>; yields {void}</i>
4845 %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]4846</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4847
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4848</div>
4849
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4850<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4851<h4>
4852<a name="i_fence">'<tt>fence</tt>' Instruction</a>
4853</h4>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4854
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4855<div>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4856
4857<h5>Syntax:</h5>
4858<pre>
4859 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4860</pre>
4861
4862<h5>Overview:</h5>
4863<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4864between operations.</p>
4865
4866<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4867href="#ordering">ordering</a> argument which defines what
4868<i>synchronizes-with</i> edges they add. They can only be given
4869<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4870<code>seq_cst</code> orderings.</p>
4871
4872<h5>Semantics:</h5>
4873<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4874semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4875<code>acquire</code> ordering semantics if and only if there exist atomic
4876operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4877<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4878<var>X</var> modifies <var>M</var> (either directly or through some side effect
4879of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4880<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4881<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4882than an explicit <code>fence</code>, one (but not both) of the atomic operations
4883<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4884<code>acquire</code> (resp.) ordering constraint and still
4885<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4886<i>happens-before</i> edge.</p>
4887
4888<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4889having both <code>acquire</code> and <code>release</code> semantics specified
4890above, participates in the global program order of other <code>seq_cst</code>
4891operations and/or fences.</p>
4892
4893<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4894specifies that the fence only synchronizes with other fences in the same
4895thread. (This is useful for interacting with signal handlers.)</p>
4896
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4897<h5>Example:</h5>
4898<pre>
4899 fence acquire <i>; yields {void}</i>
4900 fence singlethread seq_cst <i>; yields {void}</i>
4901</pre>
4902
4903</div>
4904
4905<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4906<h4>
4907<a name="i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a>
4908</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4909
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4910<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4911
4912<h5>Syntax:</h5>
4913<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4914 cmpxchg [volatile] &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;cmp&gt;, &lt;ty&gt; &lt;new&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4915</pre>
4916
4917<h5>Overview:</h5>
4918<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4919It loads a value in memory and compares it to a given value. If they are
4920equal, it stores a new value into the memory.</p>
4921
4922<h5>Arguments:</h5>
4923<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4924address to operate on, a value to compare to the value currently be at that
4925address, and a new value to place at that address if the compared values are
4926equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4927bit width is a power of two greater than or equal to eight and less than
4928or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4929'<var>&lt;new&gt;</var>' must have the same type, and the type of
4930'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4931<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4932optimizer is not allowed to modify the number or order of execution
4933of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4934operations</a>.</p>
4935
4936<!-- FIXME: Extend allowed types. -->
4937
4938<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4939<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4940
4941<p>The optional "<code>singlethread</code>" argument declares that the
4942<code>cmpxchg</code> is only atomic with respect to code (usually signal
4943handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4944cmpxchg is atomic with respect to all other code in the system.</p>
4945
4946<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4947the size in memory of the operand.
4948
4949<h5>Semantics:</h5>
4950<p>The contents of memory at the location specified by the
4951'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4952'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4953'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4954is returned.
4955
4956<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4957purpose of identifying <a href="#release_sequence">release sequences</a>. A
4958failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4959parameter determined by dropping any <code>release</code> part of the
4960<code>cmpxchg</code>'s ordering.</p>
4961
4962<!--
4963FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4964optimization work on ARM.)
4965
4966FIXME: Is a weaker ordering constraint on failure helpful in practice?
4967-->
4968
4969<h5>Example:</h5>
4970<pre>
4971entry:
4972 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4973 <a href="#i_br">br</a> label %loop
4974
4975loop:
4976 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4977 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4978 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4979 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4980 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4981
4982done:
4983 ...
4984</pre>
4985
4986</div>
4987
4988<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4989<h4>
4990<a name="i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a>
4991</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4992
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4993<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4994
4995<h5>Syntax:</h5>
4996<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4997 atomicrmw [volatile] &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4998</pre>
4999
5000<h5>Overview:</h5>
5001<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
5002
5003<h5>Arguments:</h5>
5004<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
5005operation to apply, an address whose value to modify, an argument to the
5006operation. The operation must be one of the following keywords:</p>
5007<ul>
5008 <li>xchg</li>
5009 <li>add</li>
5010 <li>sub</li>
5011 <li>and</li>
5012 <li>nand</li>
5013 <li>or</li>
5014 <li>xor</li>
5015 <li>max</li>
5016 <li>min</li>
5017 <li>umax</li>
5018 <li>umin</li>
5019</ul>
5020
5021<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
5022bit width is a power of two greater than or equal to eight and less than
5023or equal to a target-specific size limit. The type of the
5024'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
5025If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
5026optimizer is not allowed to modify the number or order of execution of this
5027<code>atomicrmw</code> with other <a href="#volatile">volatile
5028 operations</a>.</p>
5029
5030<!-- FIXME: Extend allowed types. -->
5031
5032<h5>Semantics:</h5>
5033<p>The contents of memory at the location specified by the
5034'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
5035back. The original value at the location is returned. The modification is
5036specified by the <var>operation</var> argument:</p>
5037
5038<ul>
5039 <li>xchg: <code>*ptr = val</code></li>
5040 <li>add: <code>*ptr = *ptr + val</code></li>
5041 <li>sub: <code>*ptr = *ptr - val</code></li>
5042 <li>and: <code>*ptr = *ptr &amp; val</code></li>
5043 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
5044 <li>or: <code>*ptr = *ptr | val</code></li>
5045 <li>xor: <code>*ptr = *ptr ^ val</code></li>
5046 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
5047 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
5048 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
5049 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
5050</ul>
5051
5052<h5>Example:</h5>
5053<pre>
5054 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
5055</pre>
5056
5057</div>
5058
5059<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5060<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5061 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5062</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5063
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5064<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5065
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5066<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5067<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5068 &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]5069 &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]5070</pre>
5071
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5072<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5073<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5074 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
5075 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5076
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5077<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5078<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]5079 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5080 elements of the aggregate object are indexed. The interpretation of each
5081 index is dependent on the type being indexed into. The first index always
5082 indexes the pointer value given as the first argument, the second index
5083 indexes a value of the type pointed to (not necessarily the value directly
5084 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5085 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]5086 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5087 can never be pointers, since that would require loading the pointer before
5088 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5089
5090<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]5091 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5092 integer <b>constants</b> are allowed. When indexing into an array, pointer
5093 or vector, integers of any width are allowed, and they are not required to be
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5094 constant. These integers are treated as signed values where relevant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5095
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5096<p>For example, let's consider a C code fragment and how it gets compiled to
5097 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5098
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5099<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5100struct RT {
5101 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]5102 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5103 char C;
5104};
5105struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]5106 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5107 double Y;
5108 struct RT Z;
5109};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5110
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]5111int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5112 return &amp;s[1].Z.B[5][13];
5113}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5114</pre>
5115
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5116<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5117
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5118<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]5119%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
5120%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5121
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]5122define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5123entry:
5124 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
5125 ret i32* %reg
5126}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5127</pre>
5128
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5129<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5130<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]5131 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
5132 }</tt>' type, a structure. The second index indexes into the third element
5133 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
5134 i8 }</tt>' type, another structure. The third index indexes into the second
5135 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
5136 array. The two dimensions of the array are subscripted into, yielding an
5137 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
5138 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5139
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5140<p>Note that it is perfectly legal to index partially through a structure,
5141 returning a pointer to an inner element. Because of this, the LLVM code for
5142 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5143
5144<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]5145 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5146 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]5147 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
5148 %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]5149 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
5150 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
5151 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5152 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5153</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]5154
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5155<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]5156 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
5157 base pointer is not an <i>in bounds</i> address of an allocated object,
5158 or if any of the addresses that would be formed by successive addition of
5159 the offsets implied by the indices to the base address with infinitely
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5160 precise signed arithmetic are not an <i>in bounds</i> address of that
5161 allocated object. The <i>in bounds</i> addresses for an allocated object
5162 are all the addresses that point into the object, plus the address one
5163 byte past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5164
5165<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5166 the base address with silently-wrapping two's complement arithmetic. If the
5167 offsets have a different width from the pointer, they are sign-extended or
5168 truncated to the width of the pointer. The result value of the
5169 <tt>getelementptr</tt> may be outside the object pointed to by the base
5170 pointer. The result value may not necessarily be used to access memory
5171 though, even if it happens to point into allocated storage. See the
5172 <a href="#pointeraliasing">Pointer Aliasing Rules</a> section for more
5173 information.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5174
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5175<p>The getelementptr instruction is often confusing. For some more insight into
5176 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]5177
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5178<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5179<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5180 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5181 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5182 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5183 %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]5184 <i>; yields i8*:eptr</i>
5185 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]5186 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]5187 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5188</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5189
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5190</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5191
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5192</div>
5193
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5194<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5195<h3>
5196 <a name="convertops">Conversion Operations</a>
5197</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5198
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5199<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5200
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5201<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5202 which all take a single operand and a type. They perform various bit
5203 conversions on the operand.</p>
5204
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5205<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5206<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5207 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5208</h4>
5209
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5210<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5211
5212<h5>Syntax:</h5>
5213<pre>
5214 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5215</pre>
5216
5217<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5218<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5219 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5220
5221<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5222<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5223 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5224 of the same number of integers.
5225 The bit size of the <tt>value</tt> must be larger than
5226 the bit size of the destination type, <tt>ty2</tt>.
5227 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5228
5229<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5230<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5231 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5232 source size must be larger than the destination size, <tt>trunc</tt> cannot
5233 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5234
5235<h5>Example:</h5>
5236<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5237 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5238 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5239 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5240 %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]5241</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5242
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5243</div>
5244
5245<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5246<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5247 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5248</h4>
5249
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5250<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5251
5252<h5>Syntax:</h5>
5253<pre>
5254 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5255</pre>
5256
5257<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5258<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5259 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5260
5261
5262<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5263<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5264 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5265 of the same number of integers.
5266 The bit size of the <tt>value</tt> must be smaller than
5267 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5268 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5269
5270<h5>Semantics:</h5>
5271<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]5272 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5273
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5274<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]5275
5276<h5>Example:</h5>
5277<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5278 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5279 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5280 %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]5281</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5282
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5283</div>
5284
5285<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5286<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5287 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5288</h4>
5289
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5290<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5291
5292<h5>Syntax:</h5>
5293<pre>
5294 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5295</pre>
5296
5297<h5>Overview:</h5>
5298<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5299
5300<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5301<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5302 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5303 of the same number of integers.
5304 The bit size of the <tt>value</tt> must be smaller than
5305 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5306 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5307
5308<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5309<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5310 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5311 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5312
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5313<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]5314
5315<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5316<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5317 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5318 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5319 %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]5320</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5321
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5322</div>
5323
5324<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5325<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5326 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5327</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5328
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5329<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5330
5331<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5332<pre>
5333 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5334</pre>
5335
5336<h5>Overview:</h5>
5337<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5338 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5339
5340<h5>Arguments:</h5>
5341<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5342 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5343 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]5344 <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]5345 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5346
5347<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5348<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5349 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5350 <a href="#t_floating">floating point</a> type. If the value cannot fit
5351 within the destination type, <tt>ty2</tt>, then the results are
5352 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5353
5354<h5>Example:</h5>
5355<pre>
5356 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5357 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5358</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5359
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5360</div>
5361
5362<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5363<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5364 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5365</h4>
5366
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5367<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5368
5369<h5>Syntax:</h5>
5370<pre>
5371 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5372</pre>
5373
5374<h5>Overview:</h5>
5375<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]5376 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5377
5378<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5379<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5380 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5381 a <a href="#t_floating">floating point</a> type to cast it to. The source
5382 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5383
5384<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5385<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5386 <a href="#t_floating">floating point</a> type to a larger
5387 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5388 used to make a <i>no-op cast</i> because it always changes bits. Use
5389 <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]5390
5391<h5>Example:</h5>
5392<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5393 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5394 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5395</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5396
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5397</div>
5398
5399<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5400<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5401 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5402</h4>
5403
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5404<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5405
5406<h5>Syntax:</h5>
5407<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5408 &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]5409</pre>
5410
5411<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5412<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5413 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5414
5415<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5416<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5417 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5418 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5419 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5420 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5421
5422<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5423<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5424 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5425 towards zero) unsigned integer value. If the value cannot fit
5426 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5427
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5428<h5>Example:</h5>
5429<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5430 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5431 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5432 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5433</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5434
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5435</div>
5436
5437<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5438<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5439 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5440</h4>
5441
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5442<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5443
5444<h5>Syntax:</h5>
5445<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5446 &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]5447</pre>
5448
5449<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5450<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5451 <a href="#t_floating">floating point</a> <tt>value</tt> to
5452 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5453
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5454<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5455<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5456 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5457 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5458 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5459 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5460
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5461<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5462<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5463 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5464 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5465 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5466
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5467<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5468<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5469 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5470 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5471 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5472</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5473
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5474</div>
5475
5476<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5477<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5478 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5479</h4>
5480
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5481<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5482
5483<h5>Syntax:</h5>
5484<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5485 &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]5486</pre>
5487
5488<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5489<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5490 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5491
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5492<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5493<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]5494 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5495 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5496 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5497 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5498
5499<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5500<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5501 integer quantity and converts it to the corresponding floating point
5502 value. If the value cannot fit in the floating point value, the results are
5503 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5504
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5505<h5>Example:</h5>
5506<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5507 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5508 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5509</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5510
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5511</div>
5512
5513<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5514<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5515 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5516</h4>
5517
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5518<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5519
5520<h5>Syntax:</h5>
5521<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5522 &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]5523</pre>
5524
5525<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5526<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5527 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5528
5529<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5530<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]5531 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5532 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5533 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5534 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5535
5536<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5537<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5538 quantity and converts it to the corresponding floating point value. If the
5539 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5540
5541<h5>Example:</h5>
5542<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5543 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5544 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5545</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5546
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5547</div>
5548
5549<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5550<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5551 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5552</h4>
5553
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5554<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5555
5556<h5>Syntax:</h5>
5557<pre>
5558 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5559</pre>
5560
5561<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5562<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5563 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5564
5565<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5566<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5567 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5568 <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]5569
5570<h5>Semantics:</h5>
5571<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5572 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5573 truncating or zero extending that value to the size of the integer type. If
5574 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5575 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5576 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5577 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5578
5579<h5>Example:</h5>
5580<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5581 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5582 %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]5583</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5584
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5585</div>
5586
5587<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5588<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5589 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5590</h4>
5591
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5592<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5593
5594<h5>Syntax:</h5>
5595<pre>
5596 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5597</pre>
5598
5599<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5600<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5601 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5602
5603<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5604<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5605 value to cast, and a type to cast it to, which must be a
5606 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5607
5608<h5>Semantics:</h5>
5609<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5610 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5611 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5612 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5613 than the size of a pointer then a zero extension is done. If they are the
5614 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5615
5616<h5>Example:</h5>
5617<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5618 %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]5619 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5620 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5621</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5622
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5623</div>
5624
5625<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5626<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5627 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5628</h4>
5629
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5630<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5631
5632<h5>Syntax:</h5>
5633<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5634 &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]5635</pre>
5636
5637<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5638<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5639 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5640
5641<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5642<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5643 non-aggregate first class value, and a type to cast it to, which must also be
5644 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5645 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5646 identical. If the source type is a pointer, the destination type must also be
5647 a pointer. This instruction supports bitwise conversion of vectors to
5648 integers and to vectors of other types (as long as they have the same
5649 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5650
5651<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5652<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5653 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5654 this conversion. The conversion is done as if the <tt>value</tt> had been
5655 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5656 be converted to other pointer types with this instruction. To convert
5657 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5658 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5659
5660<h5>Example:</h5>
5661<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5662 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5663 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5664 %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]5665</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5666
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5667</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5668
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5669</div>
5670
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5671<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5672<h3>
5673 <a name="otherops">Other Operations</a>
5674</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5675
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5676<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5677
5678<p>The instructions in this category are the "miscellaneous" instructions, which
5679 defy better classification.</p>
5680
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5681<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5682<h4>
5683 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5684</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5685
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5686<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5687
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5688<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5689<pre>
5690 &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]5691</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5692
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5693<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5694<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5695 boolean values based on comparison of its two integer, integer vector, or
5696 pointer operands.</p>
5697
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5698<h5>Arguments:</h5>
5699<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5700 the condition code indicating the kind of comparison to perform. It is not a
5701 value, just a keyword. The possible condition code are:</p>
5702
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5703<ol>
5704 <li><tt>eq</tt>: equal</li>
5705 <li><tt>ne</tt>: not equal </li>
5706 <li><tt>ugt</tt>: unsigned greater than</li>
5707 <li><tt>uge</tt>: unsigned greater or equal</li>
5708 <li><tt>ult</tt>: unsigned less than</li>
5709 <li><tt>ule</tt>: unsigned less or equal</li>
5710 <li><tt>sgt</tt>: signed greater than</li>
5711 <li><tt>sge</tt>: signed greater or equal</li>
5712 <li><tt>slt</tt>: signed less than</li>
5713 <li><tt>sle</tt>: signed less or equal</li>
5714</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5715
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5716<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5717 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5718 typed. They must also be identical types.</p>
5719
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5720<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5721<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5722 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5723 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]5724 result, as follows:</p>
5725
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5726<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5727 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5728 <tt>false</tt> otherwise. No sign interpretation is necessary or
5729 performed.</li>
5730
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5731 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5732 <tt>false</tt> otherwise. No sign interpretation is necessary or
5733 performed.</li>
5734
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5735 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5736 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5737
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5738 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5739 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5740 to <tt>op2</tt>.</li>
5741
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5742 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5743 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5744
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5745 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5746 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5747
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5748 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5750
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5751 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5752 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5753 to <tt>op2</tt>.</li>
5754
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5755 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5756 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5757
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5758 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5759 <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]5760</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5761
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5762<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5763 values are compared as if they were integers.</p>
5764
5765<p>If the operands are integer vectors, then they are compared element by
5766 element. The result is an <tt>i1</tt> vector with the same number of elements
5767 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5768
5769<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5770<pre>
5771 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5772 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5773 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5774 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5775 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5776 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5777</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5778
5779<p>Note that the code generator does not yet support vector types with
5780 the <tt>icmp</tt> instruction.</p>
5781
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5782</div>
5783
5784<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5785<h4>
5786 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5787</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5788
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5789<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5790
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5791<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5792<pre>
5793 &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]5794</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5795
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5796<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5797<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5798 values based on comparison of its operands.</p>
5799
5800<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]5801(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5802
5803<p>If the operands are floating point vectors, then the result type is a vector
5804 of boolean with the same number of elements as the operands being
5805 compared.</p>
5806
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5807<h5>Arguments:</h5>
5808<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5809 the condition code indicating the kind of comparison to perform. It is not a
5810 value, just a keyword. The possible condition code are:</p>
5811
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5812<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5813 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5814 <li><tt>oeq</tt>: ordered and equal</li>
5815 <li><tt>ogt</tt>: ordered and greater than </li>
5816 <li><tt>oge</tt>: ordered and greater than or equal</li>
5817 <li><tt>olt</tt>: ordered and less than </li>
5818 <li><tt>ole</tt>: ordered and less than or equal</li>
5819 <li><tt>one</tt>: ordered and not equal</li>
5820 <li><tt>ord</tt>: ordered (no nans)</li>
5821 <li><tt>ueq</tt>: unordered or equal</li>
5822 <li><tt>ugt</tt>: unordered or greater than </li>
5823 <li><tt>uge</tt>: unordered or greater than or equal</li>
5824 <li><tt>ult</tt>: unordered or less than </li>
5825 <li><tt>ule</tt>: unordered or less than or equal</li>
5826 <li><tt>une</tt>: unordered or not equal</li>
5827 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5828 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5829</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5830
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5831<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5832 <i>unordered</i> means that either operand may be a QNAN.</p>
5833
5834<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5835 a <a href="#t_floating">floating point</a> type or
5836 a <a href="#t_vector">vector</a> of floating point type. They must have
5837 identical types.</p>
5838
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5839<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5840<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5841 according to the condition code given as <tt>cond</tt>. If the operands are
5842 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5843 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5844 follows:</p>
5845
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5846<ol>
5847 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5848
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5849 <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]5850 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5851
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5852 <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]5853 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5854
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5855 <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]5856 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5857
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5858 <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]5859 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5860
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5861 <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]5862 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5863
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5864 <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]5865 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5866
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5867 <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]5868
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5869 <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]5870 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5871
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5872 <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]5873 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5874
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5875 <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]5876 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5877
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5878 <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]5879 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5880
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5881 <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]5882 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5883
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5884 <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]5885 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5886
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5887 <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]5888
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5889 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5890</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5891
5892<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5893<pre>
5894 &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]5895 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5896 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5897 &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]5898</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5899
5900<p>Note that the code generator does not yet support vector types with
5901 the <tt>fcmp</tt> instruction.</p>
5902
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5903</div>
5904
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5905<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5906<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5907 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5908</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5909
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5910<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5911
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5912<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5913<pre>
5914 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5915</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5916
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5917<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5918<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5919 SSA graph representing the function.</p>
5920
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5921<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5922<p>The type of the incoming values is specified with the first type field. After
5923 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5924 one pair for each predecessor basic block of the current block. Only values
5925 of <a href="#t_firstclass">first class</a> type may be used as the value
5926 arguments to the PHI node. Only labels may be used as the label
5927 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5928
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5929<p>There must be no non-phi instructions between the start of a basic block and
5930 the PHI instructions: i.e. PHI instructions must be first in a basic
5931 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5932
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5933<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5934 occur on the edge from the corresponding predecessor block to the current
5935 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5936 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5937
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5938<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5939<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5940 specified by the pair corresponding to the predecessor basic block that
5941 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5942
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5943<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5944<pre>
5945Loop: ; Infinite loop that counts from 0 on up...
5946 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5947 %nextindvar = add i32 %indvar, 1
5948 br label %Loop
5949</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5950
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5951</div>
5952
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5953<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5954<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5955 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5956</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5957
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5958<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5959
5960<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5961<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5962 &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>
5963
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5964 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5965</pre>
5966
5967<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5968<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5969 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5970
5971
5972<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5973<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5974 values indicating the condition, and two values of the
5975 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5976 vectors and the condition is a scalar, then entire vectors are selected, not
5977 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5978
5979<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5980<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5981 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5982
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5983<p>If the condition is a vector of i1, then the value arguments must be vectors
5984 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5985
5986<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5987<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5988 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5989</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5990
5991<p>Note that the code generator does not yet support conditions
5992 with vector type.</p>
5993
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5994</div>
5995
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5996<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5997<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5998 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5999</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6000
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6001<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6002
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6003<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6004<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]6005 &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]6006</pre>
6007
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6008<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6009<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6010
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6011<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6012<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6013
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]6014<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6015 <li>The optional "tail" marker indicates that the callee function does not
6016 access any allocas or varargs in the caller. Note that calls may be
6017 marked "tail" even if they do not occur before
6018 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
6019 present, the function call is eligible for tail call optimization,
6020 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]6021 optimized into a jump</a>. The code generator may optimize calls marked
6022 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
6023 sibling call optimization</a> when the caller and callee have
6024 matching signatures, or 2) forced tail call optimization when the
6025 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6026 <ul>
6027 <li>Caller and callee both have the calling
6028 convention <tt>fastcc</tt>.</li>
6029 <li>The call is in tail position (ret immediately follows call and ret
6030 uses value of call or is void).</li>
6031 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]6032 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6033 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
6034 constraints are met.</a></li>
6035 </ul>
6036 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]6037
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6038 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
6039 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6040 defaults to using C calling conventions. The calling convention of the
6041 call must match the calling convention of the target function, or else the
6042 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]6043
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6044 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
6045 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
6046 '<tt>inreg</tt>' attributes are valid here.</li>
6047
6048 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
6049 type of the return value. Functions that return no value are marked
6050 <tt><a href="#t_void">void</a></tt>.</li>
6051
6052 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
6053 being invoked. The argument types must match the types implied by this
6054 signature. This type can be omitted if the function is not varargs and if
6055 the function type does not return a pointer to a function.</li>
6056
6057 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
6058 be invoked. In most cases, this is a direct function invocation, but
6059 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
6060 to function value.</li>
6061
6062 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]6063 signature argument types and parameter attributes. All arguments must be
6064 of <a href="#t_firstclass">first class</a> type. If the function
6065 signature indicates the function accepts a variable number of arguments,
6066 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6067
6068 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
6069 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
6070 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]6071</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6073<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6074<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
6075 a specified function, with its incoming arguments bound to the specified
6076 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
6077 function, control flow continues with the instruction after the function
6078 call, and the return value of the function is bound to the result
6079 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6080
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6081<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6082<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]6083 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6084 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]6085 %X = tail call i32 @foo() <i>; yields i32</i>
6086 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
6087 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]6088
6089 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]6090 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]6091 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
6092 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]6093 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]6094 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6095</pre>
6096
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]6097<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]6098standard C99 library as being the C99 library functions, and may perform
6099optimizations or generate code for them under that assumption. This is
6100something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6101freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]6102
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6103</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6104
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6105<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6106<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]6107 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6108</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6109
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6110<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6111
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6112<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6113<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6114 &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]6115</pre>
6116
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6117<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6118<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6119 the "variable argument" area of a function call. It is used to implement the
6120 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6121
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6122<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6123<p>This instruction takes a <tt>va_list*</tt> value and the type of the
6124 argument. It returns a value of the specified argument type and increments
6125 the <tt>va_list</tt> to point to the next argument. The actual type
6126 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6127
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6128<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6129<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
6130 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
6131 to the next argument. For more information, see the variable argument
6132 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6133
6134<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]6135 take a variable number of arguments, for example, the <tt>vfprintf</tt>
6136 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6137
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6138<p><tt>va_arg</tt> is an LLVM instruction instead of
6139 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
6140 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6141
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6142<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6143<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
6144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6145<p>Note that the code generator does not yet fully support va_arg on many
6146 targets. Also, it does not currently support va_arg with aggregate types on
6147 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]6148
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6149</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6150
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6151<!-- _______________________________________________________________________ -->
6152<h4>
6153 <a name="i_landingpad">'<tt>landingpad</tt>' Instruction</a>
6154</h4>
6155
6156<div>
6157
6158<h5>Syntax:</h5>
6159<pre>
Bill Wendlingbf13ee12011-08-08 08:06:05 +0000[diff] [blame]6160 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; &lt;clause&gt;+
6161 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; cleanup &lt;clause&gt;*
6162
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6163 &lt;clause&gt; := catch &lt;type&gt; &lt;value&gt;
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6164 &lt;clause&gt; := filter &lt;array constant type&gt; &lt;array constant&gt;
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6165</pre>
6166
6167<h5>Overview:</h5>
6168<p>The '<tt>landingpad</tt>' instruction is used by
6169 <a href="ExceptionHandling.html#overview">LLVM's exception handling
6170 system</a> to specify that a basic block is a landing pad &mdash; one where
6171 the exception lands, and corresponds to the code found in the
6172 <i><tt>catch</tt></i> portion of a <i><tt>try/catch</tt></i> sequence. It
6173 defines values supplied by the personality function (<tt>pers_fn</tt>) upon
6174 re-entry to the function. The <tt>resultval</tt> has the
6175 type <tt>somety</tt>.</p>
6176
6177<h5>Arguments:</h5>
6178<p>This instruction takes a <tt>pers_fn</tt> value. This is the personality
6179 function associated with the unwinding mechanism. The optional
6180 <tt>cleanup</tt> flag indicates that the landing pad block is a cleanup.</p>
6181
6182<p>A <tt>clause</tt> begins with the clause type &mdash; <tt>catch</tt>
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6183 or <tt>filter</tt> &mdash; and contains the global variable representing the
6184 "type" that may be caught or filtered respectively. Unlike the
6185 <tt>catch</tt> clause, the <tt>filter</tt> clause takes an array constant as
6186 its argument. Use "<tt>[0 x i8**] undef</tt>" for a filter which cannot
6187 throw. The '<tt>landingpad</tt>' instruction must contain <em>at least</em>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6188 one <tt>clause</tt> or the <tt>cleanup</tt> flag.</p>
6189
6190<h5>Semantics:</h5>
6191<p>The '<tt>landingpad</tt>' instruction defines the values which are set by the
6192 personality function (<tt>pers_fn</tt>) upon re-entry to the function, and
6193 therefore the "result type" of the <tt>landingpad</tt> instruction. As with
6194 calling conventions, how the personality function results are represented in
6195 LLVM IR is target specific.</p>
6196
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6197<p>The clauses are applied in order from top to bottom. If two
6198 <tt>landingpad</tt> instructions are merged together through inlining, the
Bill Wendling2905c322011-08-08 07:58:58 +0000[diff] [blame]6199 clauses from the calling function are appended to the list of clauses.</p>
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6200
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6201<p>The <tt>landingpad</tt> instruction has several restrictions:</p>
6202
6203<ul>
6204 <li>A landing pad block is a basic block which is the unwind destination of an
6205 '<tt>invoke</tt>' instruction.</li>
6206 <li>A landing pad block must have a '<tt>landingpad</tt>' instruction as its
6207 first non-PHI instruction.</li>
6208 <li>There can be only one '<tt>landingpad</tt>' instruction within the landing
6209 pad block.</li>
6210 <li>A basic block that is not a landing pad block may not include a
6211 '<tt>landingpad</tt>' instruction.</li>
6212 <li>All '<tt>landingpad</tt>' instructions in a function must have the same
6213 personality function.</li>
6214</ul>
6215
6216<h5>Example:</h5>
6217<pre>
6218 ;; A landing pad which can catch an integer.
6219 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6220 catch i8** @_ZTIi
6221 ;; A landing pad that is a cleanup.
6222 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6223 cleanup
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6224 ;; A landing pad which can catch an integer and can only throw a double.
6225 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6226 catch i8** @_ZTIi
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6227 filter [1 x i8**] [@_ZTId]
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6228</pre>
6229
6230</div>
6231
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6232</div>
6233
6234</div>
6235
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6236<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6237<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]6238<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6239
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6240<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6241
6242<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6243 well known names and semantics and are required to follow certain
6244 restrictions. Overall, these intrinsics represent an extension mechanism for
6245 the LLVM language that does not require changing all of the transformations
6246 in LLVM when adding to the language (or the bitcode reader/writer, the
6247 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6248
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]6249<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6250 prefix is reserved in LLVM for intrinsic names; thus, function names may not
6251 begin with this prefix. Intrinsic functions must always be external
6252 functions: you cannot define the body of intrinsic functions. Intrinsic
6253 functions may only be used in call or invoke instructions: it is illegal to
6254 take the address of an intrinsic function. Additionally, because intrinsic
6255 functions are part of the LLVM language, it is required if any are added that
6256 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6257
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6258<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6259 family of functions that perform the same operation but on different data
6260 types. Because LLVM can represent over 8 million different integer types,
6261 overloading is used commonly to allow an intrinsic function to operate on any
6262 integer type. One or more of the argument types or the result type can be
6263 overloaded to accept any integer type. Argument types may also be defined as
6264 exactly matching a previous argument's type or the result type. This allows
6265 an intrinsic function which accepts multiple arguments, but needs all of them
6266 to be of the same type, to only be overloaded with respect to a single
6267 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6268
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6269<p>Overloaded intrinsics will have the names of its overloaded argument types
6270 encoded into its function name, each preceded by a period. Only those types
6271 which are overloaded result in a name suffix. Arguments whose type is matched
6272 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6273 can take an integer of any width and returns an integer of exactly the same
6274 integer width. This leads to a family of functions such as
6275 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6276 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6277 suffix is required. Because the argument's type is matched against the return
6278 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6279
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6280<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6281 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6282
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6283<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6284<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6285 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6286</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6287
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6288<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6289
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6290<p>Variable argument support is defined in LLVM with
6291 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6292 intrinsic functions. These functions are related to the similarly named
6293 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6294
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6295<p>All of these functions operate on arguments that use a target-specific value
6296 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6297 not define what this type is, so all transformations should be prepared to
6298 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6299
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6300<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]6301 instruction and the variable argument handling intrinsic functions are
6302 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6303
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6304<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6305define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6306 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6307 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6308 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6309 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6310
6311 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6312 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6313
6314 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6315 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6316 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6317 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6318 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6319
6320 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6321 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6322 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6323}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6324
6325declare void @llvm.va_start(i8*)
6326declare void @llvm.va_copy(i8*, i8*)
6327declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6328</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6329
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6330<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6331<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6332 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6333</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6334
6335
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6336<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6337
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6338<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6339<pre>
6340 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6341</pre>
6342
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6343<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6344<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6345 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]6346
6347<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6348<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]6349
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6350<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6351<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]6352 macro available in C. In a target-dependent way, it initializes
6353 the <tt>va_list</tt> element to which the argument points, so that the next
6354 call to <tt>va_arg</tt> will produce the first variable argument passed to
6355 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6356 need to know the last argument of the function as the compiler can figure
6357 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6358
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6359</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6360
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6361<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6362<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6363 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6364</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6365
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6366<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6367
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6368<h5>Syntax:</h5>
6369<pre>
6370 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6371</pre>
6372
6373<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6374<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6375 which has been initialized previously
6376 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6377 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6378
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6379<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6380<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]6381
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6382<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6383<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]6384 macro available in C. In a target-dependent way, it destroys
6385 the <tt>va_list</tt> element to which the argument points. Calls
6386 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6387 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6388 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6389
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6390</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6391
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6392<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6393<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6394 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6395</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6397<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6398
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6399<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6400<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6401 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6402</pre>
6403
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6404<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6405<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6406 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6407
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6408<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6409<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]6410 The second argument is a pointer to a <tt>va_list</tt> element to copy
6411 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6412
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6413<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6414<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]6415 macro available in C. In a target-dependent way, it copies the
6416 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6417 element. This intrinsic is necessary because
6418 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6419 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6420
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6421</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6422
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6423</div>
6424
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6425<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6426<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6427 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6428</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6429
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6430<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6431
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6432<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6433Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6434intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6435roots on the stack</a>, as well as garbage collector implementations that
6436require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6437barriers. Front-ends for type-safe garbage collected languages should generate
6438these intrinsics to make use of the LLVM garbage collectors. For more details,
6439see <a href="GarbageCollection.html">Accurate Garbage Collection with
6440LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6441
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6442<p>The garbage collection intrinsics only operate on objects in the generic
6443 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6444
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6445<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6446<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6447 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6448</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6449
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6450<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6451
6452<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6453<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6454 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6455</pre>
6456
6457<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6458<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]6459 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6460
6461<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6462<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6463 root pointer. The second pointer (which must be either a constant or a
6464 global value address) contains the meta-data to be associated with the
6465 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6466
6467<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6468<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]6469 location. At compile-time, the code generator generates information to allow
6470 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6471 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6472 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6473
6474</div>
6475
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6476<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6477<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6478 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6479</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6480
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6481<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6482
6483<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6484<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6485 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6486</pre>
6487
6488<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6489<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6490 locations, allowing garbage collector implementations that require read
6491 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6492
6493<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6494<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]6495 allocated from the garbage collector. The first object is a pointer to the
6496 start of the referenced object, if needed by the language runtime (otherwise
6497 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6498
6499<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6500<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6501 instruction, but may be replaced with substantially more complex code by the
6502 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6503 may only be used in a function which <a href="#gc">specifies a GC
6504 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6505
6506</div>
6507
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6508<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6509<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6510 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6511</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6512
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6513<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6514
6515<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6516<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6517 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6518</pre>
6519
6520<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6521<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6522 locations, allowing garbage collector implementations that require write
6523 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6524
6525<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6526<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]6527 object to store it to, and the third is the address of the field of Obj to
6528 store to. If the runtime does not require a pointer to the object, Obj may
6529 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6530
6531<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6532<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6533 instruction, but may be replaced with substantially more complex code by the
6534 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6535 may only be used in a function which <a href="#gc">specifies a GC
6536 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6537
6538</div>
6539
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6540</div>
6541
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6542<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6543<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6544 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6545</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6546
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6547<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6548
6549<p>These intrinsics are provided by LLVM to expose special features that may
6550 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6551
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6552<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6553<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6554 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6555</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6556
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6557<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6558
6559<h5>Syntax:</h5>
6560<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6561 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6562</pre>
6563
6564<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6565<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6566 target-specific value indicating the return address of the current function
6567 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6568
6569<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6570<p>The argument to this intrinsic indicates which function to return the address
6571 for. Zero indicates the calling function, one indicates its caller, etc.
6572 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6573
6574<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6575<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6576 indicating the return address of the specified call frame, or zero if it
6577 cannot be identified. The value returned by this intrinsic is likely to be
6578 incorrect or 0 for arguments other than zero, so it should only be used for
6579 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6580
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6581<p>Note that calling this intrinsic does not prevent function inlining or other
6582 aggressive transformations, so the value returned may not be that of the
6583 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6584
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6585</div>
6586
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6587<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6588<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6589 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6590</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6591
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6592<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6593
6594<h5>Syntax:</h5>
6595<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6596 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6597</pre>
6598
6599<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6600<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6601 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6602
6603<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6604<p>The argument to this intrinsic indicates which function to return the frame
6605 pointer for. Zero indicates the calling function, one indicates its caller,
6606 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6607
6608<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6609<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6610 indicating the frame address of the specified call frame, or zero if it
6611 cannot be identified. The value returned by this intrinsic is likely to be
6612 incorrect or 0 for arguments other than zero, so it should only be used for
6613 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6614
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6615<p>Note that calling this intrinsic does not prevent function inlining or other
6616 aggressive transformations, so the value returned may not be that of the
6617 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6618
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6619</div>
6620
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6621<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6622<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6623 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6624</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6625
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6626<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6627
6628<h5>Syntax:</h5>
6629<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6630 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6631</pre>
6632
6633<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6634<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6635 of the function stack, for use
6636 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6637 useful for implementing language features like scoped automatic variable
6638 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6639
6640<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6641<p>This intrinsic returns a opaque pointer value that can be passed
6642 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6643 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6644 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6645 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6646 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6647 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6648
6649</div>
6650
6651<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6652<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6653 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6654</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6655
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6656<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6657
6658<h5>Syntax:</h5>
6659<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6660 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6661</pre>
6662
6663<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6664<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6665 the function stack to the state it was in when the
6666 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6667 executed. This is useful for implementing language features like scoped
6668 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6669
6670<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6671<p>See the description
6672 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6673
6674</div>
6675
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6676<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6677<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6678 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6679</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6680
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6681<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6682
6683<h5>Syntax:</h5>
6684<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6685 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]6686</pre>
6687
6688<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6689<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6690 insert a prefetch instruction if supported; otherwise, it is a noop.
6691 Prefetches have no effect on the behavior of the program but can change its
6692 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6693
6694<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6695<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6696 specifier determining if the fetch should be for a read (0) or write (1),
6697 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6698 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6699 specifies whether the prefetch is performed on the data (1) or instruction (0)
6700 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6701 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6702
6703<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6704<p>This intrinsic does not modify the behavior of the program. In particular,
6705 prefetches cannot trap and do not produce a value. On targets that support
6706 this intrinsic, the prefetch can provide hints to the processor cache for
6707 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6708
6709</div>
6710
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6711<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6712<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6713 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6714</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6715
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6716<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6717
6718<h5>Syntax:</h5>
6719<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6720 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6721</pre>
6722
6723<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6724<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6725 Counter (PC) in a region of code to simulators and other tools. The method
6726 is target specific, but it is expected that the marker will use exported
6727 symbols to transmit the PC of the marker. The marker makes no guarantees
6728 that it will remain with any specific instruction after optimizations. It is
6729 possible that the presence of a marker will inhibit optimizations. The
6730 intended use is to be inserted after optimizations to allow correlations of
6731 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6732
6733<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6734<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6735
6736<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6737<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6738 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6739
6740</div>
6741
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6742<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6743<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6744 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6745</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6746
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6747<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6748
6749<h5>Syntax:</h5>
6750<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6751 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6752</pre>
6753
6754<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6755<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6756 counter register (or similar low latency, high accuracy clocks) on those
6757 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6758 should map to RPCC. As the backing counters overflow quickly (on the order
6759 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6760
6761<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6762<p>When directly supported, reading the cycle counter should not modify any
6763 memory. Implementations are allowed to either return a application specific
6764 value or a system wide value. On backends without support, this is lowered
6765 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6766
6767</div>
6768
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6769</div>
6770
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6771<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6772<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6773 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6774</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6775
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6776<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6777
6778<p>LLVM provides intrinsics for a few important standard C library functions.
6779 These intrinsics allow source-language front-ends to pass information about
6780 the alignment of the pointer arguments to the code generator, providing
6781 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6782
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6783<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6784<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6785 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6786</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6787
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6788<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6789
6790<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6791<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]6792 integer bit width and for different address spaces. Not all targets support
6793 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6794
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6795<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6796 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]6797 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6798 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]6799 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6800</pre>
6801
6802<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6803<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6804 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6805
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6806<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6807 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6808 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6809
6810<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6812<p>The first argument is a pointer to the destination, the second is a pointer
6813 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6814 number of bytes to copy, the fourth argument is the alignment of the
6815 source and destination locations, and the fifth is a boolean indicating a
6816 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6817
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6818<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]6819 then the caller guarantees that both the source and destination pointers are
6820 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6821
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6822<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6823 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6824 The detailed access behavior is not very cleanly specified and it is unwise
6825 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6826
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6827<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6829<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6830 source location to the destination location, which are not allowed to
6831 overlap. It copies "len" bytes of memory over. If the argument is known to
6832 be aligned to some boundary, this can be specified as the fourth argument,
6833 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6834
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6835</div>
6836
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6837<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6838<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6839 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6840</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6841
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6842<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6843
6844<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6845<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]6846 width and for different address space. Not all targets support all bit
6847 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6848
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6849<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6850 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]6851 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6852 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]6853 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6854</pre>
6855
6856<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6857<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6858 source location to the destination location. It is similar to the
6859 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6860 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6861
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6862<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6863 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6864 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6865
6866<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6867
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6868<p>The first argument is a pointer to the destination, the second is a pointer
6869 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6870 number of bytes to copy, the fourth argument is the alignment of the
6871 source and destination locations, and the fifth is a boolean indicating a
6872 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6873
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6874<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]6875 then the caller guarantees that the source and destination pointers are
6876 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6877
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6878<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6879 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6880 The detailed access behavior is not very cleanly specified and it is unwise
6881 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6882
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6883<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6884
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6885<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6886 source location to the destination location, which may overlap. It copies
6887 "len" bytes of memory over. If the argument is known to be aligned to some
6888 boundary, this can be specified as the fourth argument, otherwise it should
6889 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6890
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6891</div>
6892
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6893<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6894<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6895 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6896</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6897
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6898<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6899
6900<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6901<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]6902 width and for different address spaces. However, not all targets support all
6903 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6904
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6905<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6906 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6907 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6908 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6909 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6910</pre>
6911
6912<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6913<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6914 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6915
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6916<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6917 intrinsic does not return a value and takes extra alignment/volatile
6918 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6919
6920<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6921<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]6922 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6923 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6924 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6925
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6926<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]6927 then the caller guarantees that the destination pointer is aligned to that
6928 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6929
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6930<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6931 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6932 The detailed access behavior is not very cleanly specified and it is unwise
6933 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6934
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6935<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6936<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6937 at the destination location. If the argument is known to be aligned to some
6938 boundary, this can be specified as the fourth argument, otherwise it should
6939 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6940
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6941</div>
6942
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6943<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6944<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6945 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6946</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6947
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6948<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6949
6950<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6951<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6952 floating point or vector of floating point type. Not all targets support all
6953 types however.</p>
6954
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6955<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6956 declare float @llvm.sqrt.f32(float %Val)
6957 declare double @llvm.sqrt.f64(double %Val)
6958 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6959 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6960 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6961</pre>
6962
6963<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6964<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6965 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6966 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6967 behavior for negative numbers other than -0.0 (which allows for better
6968 optimization, because there is no need to worry about errno being
6969 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]6970
6971<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6972<p>The argument and return value are floating point numbers of the same
6973 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6974
6975<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6976<p>This function returns the sqrt of the specified operand if it is a
6977 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6978
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6979</div>
6980
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6981<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6982<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6983 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6984</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6985
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6986<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6987
6988<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6989<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6990 floating point or vector of floating point type. Not all targets support all
6991 types however.</p>
6992
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6993<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6994 declare float @llvm.powi.f32(float %Val, i32 %power)
6995 declare double @llvm.powi.f64(double %Val, i32 %power)
6996 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6997 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6998 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6999</pre>
7000
7001<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7002<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
7003 specified (positive or negative) power. The order of evaluation of
7004 multiplications is not defined. When a vector of floating point type is
7005 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7006
7007<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7008<p>The second argument is an integer power, and the first is a value to raise to
7009 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7010
7011<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7012<p>This function returns the first value raised to the second power with an
7013 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7014
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7015</div>
7016
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7017<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7018<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7019 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7020</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7021
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7022<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7023
7024<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7025<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
7026 floating point or vector of floating point type. Not all targets support all
7027 types however.</p>
7028
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7029<pre>
7030 declare float @llvm.sin.f32(float %Val)
7031 declare double @llvm.sin.f64(double %Val)
7032 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
7033 declare fp128 @llvm.sin.f128(fp128 %Val)
7034 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
7035</pre>
7036
7037<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7038<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7039
7040<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7041<p>The argument and return value are floating point numbers of the same
7042 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7043
7044<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7045<p>This function returns the sine of the specified operand, returning the same
7046 values as the libm <tt>sin</tt> functions would, and handles error conditions
7047 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7048
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7049</div>
7050
7051<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7052<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7053 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7054</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7055
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7056<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7057
7058<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7059<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
7060 floating point or vector of floating point type. Not all targets support all
7061 types however.</p>
7062
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7063<pre>
7064 declare float @llvm.cos.f32(float %Val)
7065 declare double @llvm.cos.f64(double %Val)
7066 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
7067 declare fp128 @llvm.cos.f128(fp128 %Val)
7068 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
7069</pre>
7070
7071<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7072<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7073
7074<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7075<p>The argument and return value are floating point numbers of the same
7076 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7077
7078<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7079<p>This function returns the cosine of the specified operand, returning the same
7080 values as the libm <tt>cos</tt> functions would, and handles error conditions
7081 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7082
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7083</div>
7084
7085<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7086<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7087 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7088</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7089
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7090<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7091
7092<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7093<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
7094 floating point or vector of floating point type. Not all targets support all
7095 types however.</p>
7096
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7097<pre>
7098 declare float @llvm.pow.f32(float %Val, float %Power)
7099 declare double @llvm.pow.f64(double %Val, double %Power)
7100 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
7101 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
7102 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
7103</pre>
7104
7105<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7106<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
7107 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7108
7109<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7110<p>The second argument is a floating point power, and the first is a value to
7111 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7112
7113<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7114<p>This function returns the first value raised to the second power, returning
7115 the same values as the libm <tt>pow</tt> functions would, and handles error
7116 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7117
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7118</div>
7119
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7120<!-- _______________________________________________________________________ -->
7121<h4>
7122 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
7123</h4>
7124
7125<div>
7126
7127<h5>Syntax:</h5>
7128<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
7129 floating point or vector of floating point type. Not all targets support all
7130 types however.</p>
7131
7132<pre>
7133 declare float @llvm.exp.f32(float %Val)
7134 declare double @llvm.exp.f64(double %Val)
7135 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
7136 declare fp128 @llvm.exp.f128(fp128 %Val)
7137 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
7138</pre>
7139
7140<h5>Overview:</h5>
7141<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
7142
7143<h5>Arguments:</h5>
7144<p>The argument and return value are floating point numbers of the same
7145 type.</p>
7146
7147<h5>Semantics:</h5>
7148<p>This function returns the same values as the libm <tt>exp</tt> functions
7149 would, and handles error conditions in the same way.</p>
7150
7151</div>
7152
7153<!-- _______________________________________________________________________ -->
7154<h4>
7155 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
7156</h4>
7157
7158<div>
7159
7160<h5>Syntax:</h5>
7161<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
7162 floating point or vector of floating point type. Not all targets support all
7163 types however.</p>
7164
7165<pre>
7166 declare float @llvm.log.f32(float %Val)
7167 declare double @llvm.log.f64(double %Val)
7168 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
7169 declare fp128 @llvm.log.f128(fp128 %Val)
7170 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
7171</pre>
7172
7173<h5>Overview:</h5>
7174<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
7175
7176<h5>Arguments:</h5>
7177<p>The argument and return value are floating point numbers of the same
7178 type.</p>
7179
7180<h5>Semantics:</h5>
7181<p>This function returns the same values as the libm <tt>log</tt> functions
7182 would, and handles error conditions in the same way.</p>
7183
Nick Lewycky1c929be2011-10-31 01:32:21 +0000[diff] [blame]7184</div>
7185
7186<!-- _______________________________________________________________________ -->
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7187<h4>
7188 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
7189</h4>
7190
7191<div>
7192
7193<h5>Syntax:</h5>
7194<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
7195 floating point or vector of floating point type. Not all targets support all
7196 types however.</p>
7197
7198<pre>
7199 declare float @llvm.fma.f32(float %a, float %b, float %c)
7200 declare double @llvm.fma.f64(double %a, double %b, double %c)
7201 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
7202 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
7203 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
7204</pre>
7205
7206<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]7207<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7208 operation.</p>
7209
7210<h5>Arguments:</h5>
7211<p>The argument and return value are floating point numbers of the same
7212 type.</p>
7213
7214<h5>Semantics:</h5>
7215<p>This function returns the same values as the libm <tt>fma</tt> functions
7216 would.</p>
7217
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7218</div>
7219
NAKAMURA Takumi4b2e07a2011-10-31 13:04:26 +0000[diff] [blame]7220</div>
7221
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7222<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7223<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7224 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7225</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7226
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7227<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7228
7229<p>LLVM provides intrinsics for a few important bit manipulation operations.
7230 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7231
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7232<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7233<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7234 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7235</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7236
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7237<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7238
7239<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7240<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7241 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
7242
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7243<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7244 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
7245 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
7246 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7247</pre>
7248
7249<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
7251 values with an even number of bytes (positive multiple of 16 bits). These
7252 are useful for performing operations on data that is not in the target's
7253 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7254
7255<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7256<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
7257 and low byte of the input i16 swapped. Similarly,
7258 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
7259 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7260 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7261 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7262 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7263 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7264
7265</div>
7266
7267<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7268<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]7269 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7270</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7271
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7272<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7273
7274<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7275<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]7276 width, or on any vector with integer elements. Not all targets support all
7277 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7278
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7279<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7280 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7281 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7282 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7283 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7284 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7285 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]7286</pre>
7287
7288<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7289<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7290 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7291
7292<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7293<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]7294 integer type, or a vector with integer elements.
7295 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7296
7297<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7298<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7299 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7300
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7301</div>
7302
7303<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7304<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7305 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7306</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7307
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7308<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7309
7310<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7311<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]7312 integer bit width, or any vector whose elements are integers. Not all
7313 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7314
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7315<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7316 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7317 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7318 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7319 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7320 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7321 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]7322</pre>
7323
7324<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7325<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7326 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7327
7328<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7329<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]7330 integer type, or any vector type with integer element type.
7331 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7332
7333<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7334<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7335 zeros in a variable, or within each element of the vector if the operation
7336 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]7337 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7338
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7339</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7340
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7341<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7342<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7343 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7344</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7345
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7346<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7347
7348<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7349<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]7350 integer bit width, or any vector of integer elements. Not all targets
7351 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7352
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7353<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7354 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7355 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7356 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7357 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7358 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7359 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]7360</pre>
7361
7362<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7363<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7364 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7365
7366<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7367<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]7368 integer type, or a vectory with integer element type.. The return type
7369 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7370
7371<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7372<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7373 zeros in a variable, or within each element of a vector.
7374 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7375 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7376
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7377</div>
7378
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7379</div>
7380
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7381<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7382<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7383 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7384</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7385
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7386<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7387
7388<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7389
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7390<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7391<h4>
7392 <a name="int_sadd_overflow">
7393 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7394 </a>
7395</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7397<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7398
7399<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7400<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]7401 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7402
7403<pre>
7404 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7405 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7406 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7407</pre>
7408
7409<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7410<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7411 a signed addition of the two arguments, and indicate whether an overflow
7412 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7413
7414<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7415<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]7416 be of integer types of any bit width, but they must have the same bit
7417 width. The second element of the result structure must be of
7418 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7419 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7420
7421<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7422<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7423 a signed addition of the two variables. They return a structure &mdash; the
7424 first element of which is the signed summation, and the second element of
7425 which is a bit specifying if the signed summation resulted in an
7426 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7427
7428<h5>Examples:</h5>
7429<pre>
7430 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7431 %sum = extractvalue {i32, i1} %res, 0
7432 %obit = extractvalue {i32, i1} %res, 1
7433 br i1 %obit, label %overflow, label %normal
7434</pre>
7435
7436</div>
7437
7438<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7439<h4>
7440 <a name="int_uadd_overflow">
7441 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7442 </a>
7443</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7444
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7445<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7446
7447<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7448<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]7449 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7450
7451<pre>
7452 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7453 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7454 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7455</pre>
7456
7457<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7458<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7459 an unsigned addition of the two arguments, and indicate whether a carry
7460 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7461
7462<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7463<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]7464 be of integer types of any bit width, but they must have the same bit
7465 width. The second element of the result structure must be of
7466 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7467 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7468
7469<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7470<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7471 an unsigned addition of the two arguments. They return a structure &mdash;
7472 the first element of which is the sum, and the second element of which is a
7473 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7474
7475<h5>Examples:</h5>
7476<pre>
7477 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7478 %sum = extractvalue {i32, i1} %res, 0
7479 %obit = extractvalue {i32, i1} %res, 1
7480 br i1 %obit, label %carry, label %normal
7481</pre>
7482
7483</div>
7484
7485<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7486<h4>
7487 <a name="int_ssub_overflow">
7488 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7489 </a>
7490</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7491
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7492<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7493
7494<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7495<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]7496 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7497
7498<pre>
7499 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7500 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7501 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7502</pre>
7503
7504<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7505<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7506 a signed subtraction of the two arguments, and indicate whether an overflow
7507 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7508
7509<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7510<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]7511 be of integer types of any bit width, but they must have the same bit
7512 width. The second element of the result structure must be of
7513 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7514 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7515
7516<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7517<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7518 a signed subtraction of the two arguments. They return a structure &mdash;
7519 the first element of which is the subtraction, and the second element of
7520 which is a bit specifying if the signed subtraction resulted in an
7521 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7522
7523<h5>Examples:</h5>
7524<pre>
7525 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7526 %sum = extractvalue {i32, i1} %res, 0
7527 %obit = extractvalue {i32, i1} %res, 1
7528 br i1 %obit, label %overflow, label %normal
7529</pre>
7530
7531</div>
7532
7533<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7534<h4>
7535 <a name="int_usub_overflow">
7536 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7537 </a>
7538</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7539
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7540<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7541
7542<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7543<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]7544 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7545
7546<pre>
7547 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7548 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7549 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7550</pre>
7551
7552<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7553<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7554 an unsigned subtraction of the two arguments, and indicate whether an
7555 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7556
7557<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7558<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]7559 be of integer types of any bit width, but they must have the same bit
7560 width. The second element of the result structure must be of
7561 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7562 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7563
7564<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7565<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7566 an unsigned subtraction of the two arguments. They return a structure &mdash;
7567 the first element of which is the subtraction, and the second element of
7568 which is a bit specifying if the unsigned subtraction resulted in an
7569 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7570
7571<h5>Examples:</h5>
7572<pre>
7573 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7574 %sum = extractvalue {i32, i1} %res, 0
7575 %obit = extractvalue {i32, i1} %res, 1
7576 br i1 %obit, label %overflow, label %normal
7577</pre>
7578
7579</div>
7580
7581<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7582<h4>
7583 <a name="int_smul_overflow">
7584 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7585 </a>
7586</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7587
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7588<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7589
7590<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7591<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]7592 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7593
7594<pre>
7595 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7596 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7597 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7598</pre>
7599
7600<h5>Overview:</h5>
7601
7602<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7603 a signed multiplication of the two arguments, and indicate whether an
7604 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7605
7606<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7607<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]7608 be of integer types of any bit width, but they must have the same bit
7609 width. The second element of the result structure must be of
7610 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7611 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7612
7613<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7614<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7615 a signed multiplication of the two arguments. They return a structure &mdash;
7616 the first element of which is the multiplication, and the second element of
7617 which is a bit specifying if the signed multiplication resulted in an
7618 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7619
7620<h5>Examples:</h5>
7621<pre>
7622 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7623 %sum = extractvalue {i32, i1} %res, 0
7624 %obit = extractvalue {i32, i1} %res, 1
7625 br i1 %obit, label %overflow, label %normal
7626</pre>
7627
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7628</div>
7629
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7630<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7631<h4>
7632 <a name="int_umul_overflow">
7633 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7634 </a>
7635</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7636
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7637<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7638
7639<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7640<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]7641 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7642
7643<pre>
7644 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7645 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7646 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7647</pre>
7648
7649<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7650<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7651 a unsigned multiplication of the two arguments, and indicate whether an
7652 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7653
7654<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7655<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]7656 be of integer types of any bit width, but they must have the same bit
7657 width. The second element of the result structure must be of
7658 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7659 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7660
7661<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7662<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7663 an unsigned multiplication of the two arguments. They return a structure
7664 &mdash; the first element of which is the multiplication, and the second
7665 element of which is a bit specifying if the unsigned multiplication resulted
7666 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7667
7668<h5>Examples:</h5>
7669<pre>
7670 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7671 %sum = extractvalue {i32, i1} %res, 0
7672 %obit = extractvalue {i32, i1} %res, 1
7673 br i1 %obit, label %overflow, label %normal
7674</pre>
7675
7676</div>
7677
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7678</div>
7679
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7680<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7681<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7682 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7683</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7684
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7685<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7686
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7687<p>Half precision floating point is a storage-only format. This means that it is
7688 a dense encoding (in memory) but does not support computation in the
7689 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7690
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7691<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7692 value as an i16, then convert it to float with <a
7693 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7694 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7695 double etc). To store the value back to memory, it is first converted to
7696 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7697 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7698 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7699
7700<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7701<h4>
7702 <a name="int_convert_to_fp16">
7703 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7704 </a>
7705</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7706
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7707<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7708
7709<h5>Syntax:</h5>
7710<pre>
7711 declare i16 @llvm.convert.to.fp16(f32 %a)
7712</pre>
7713
7714<h5>Overview:</h5>
7715<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7716 a conversion from single precision floating point format to half precision
7717 floating point format.</p>
7718
7719<h5>Arguments:</h5>
7720<p>The intrinsic function contains single argument - the value to be
7721 converted.</p>
7722
7723<h5>Semantics:</h5>
7724<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7725 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7726 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7727 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7728
7729<h5>Examples:</h5>
7730<pre>
7731 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7732 store i16 %res, i16* @x, align 2
7733</pre>
7734
7735</div>
7736
7737<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7738<h4>
7739 <a name="int_convert_from_fp16">
7740 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7741 </a>
7742</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7743
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7744<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7745
7746<h5>Syntax:</h5>
7747<pre>
7748 declare f32 @llvm.convert.from.fp16(i16 %a)
7749</pre>
7750
7751<h5>Overview:</h5>
7752<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7753 a conversion from half precision floating point format to single precision
7754 floating point format.</p>
7755
7756<h5>Arguments:</h5>
7757<p>The intrinsic function contains single argument - the value to be
7758 converted.</p>
7759
7760<h5>Semantics:</h5>
7761<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7762 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7763 precision floating point format. The input half-float value is represented by
7764 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7765
7766<h5>Examples:</h5>
7767<pre>
7768 %a = load i16* @x, align 2
7769 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7770</pre>
7771
7772</div>
7773
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7774</div>
7775
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7776<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7777<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7778 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7779</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7780
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7781<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7782
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7783<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7784 prefix), are described in
7785 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7786 Level Debugging</a> document.</p>
7787
7788</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7789
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7790<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7791<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7792 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7793</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7794
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7795<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7796
7797<p>The LLVM exception handling intrinsics (which all start with
7798 <tt>llvm.eh.</tt> prefix), are described in
7799 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7800 Handling</a> document.</p>
7801
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7802</div>
7803
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7804<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7805<h3>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7806 <a name="int_trampoline">Trampoline Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7807</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7808
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7809<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7810
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7811<p>These intrinsics make it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7812 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7813 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7814 function pointer lacking the nest parameter - the caller does not need to
7815 provide a value for it. Instead, the value to use is stored in advance in a
7816 "trampoline", a block of memory usually allocated on the stack, which also
7817 contains code to splice the nest value into the argument list. This is used
7818 to implement the GCC nested function address extension.</p>
7819
7820<p>For example, if the function is
7821 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7822 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7823 follows:</p>
7824
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7825<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7826 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7827 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7828 call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8*, i32, i32)* @f to i8*), i8* %nval)
7829 %p = call i8* @llvm.adjust.trampoline(i8* %tramp1)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7830 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7831</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7832
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7833<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7834 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7835
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7836<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7837<h4>
7838 <a name="int_it">
7839 '<tt>llvm.init.trampoline</tt>' Intrinsic
7840 </a>
7841</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7842
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7843<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7844
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7845<h5>Syntax:</h5>
7846<pre>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7847 declare void @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]7848</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7849
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7850<h5>Overview:</h5>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7851<p>This fills the memory pointed to by <tt>tramp</tt> with executable code,
7852 turning it into a trampoline.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7853
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7854<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7855<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7856 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7857 sufficiently aligned block of memory; this memory is written to by the
7858 intrinsic. Note that the size and the alignment are target-specific - LLVM
7859 currently provides no portable way of determining them, so a front-end that
7860 generates this intrinsic needs to have some target-specific knowledge.
7861 The <tt>func</tt> argument must hold a function bitcast to
7862 an <tt>i8*</tt>.</p>
7863
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7864<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7865<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7866 dependent code, turning it into a function. Then <tt>tramp</tt> needs to be
7867 passed to <a href="#int_at">llvm.adjust.trampoline</a> to get a pointer
7868 which can be <a href="#int_trampoline">bitcast (to a new function) and
7869 called</a>. The new function's signature is the same as that of
7870 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
7871 removed. At most one such <tt>nest</tt> argument is allowed, and it must be of
7872 pointer type. Calling the new function is equivalent to calling <tt>func</tt>
7873 with the same argument list, but with <tt>nval</tt> used for the missing
7874 <tt>nest</tt> argument. If, after calling <tt>llvm.init.trampoline</tt>, the
7875 memory pointed to by <tt>tramp</tt> is modified, then the effect of any later call
7876 to the returned function pointer is undefined.</p>
7877</div>
7878
7879<!-- _______________________________________________________________________ -->
7880<h4>
7881 <a name="int_at">
7882 '<tt>llvm.adjust.trampoline</tt>' Intrinsic
7883 </a>
7884</h4>
7885
7886<div>
7887
7888<h5>Syntax:</h5>
7889<pre>
7890 declare i8* @llvm.adjust.trampoline(i8* &lt;tramp&gt;)
7891</pre>
7892
7893<h5>Overview:</h5>
7894<p>This performs any required machine-specific adjustment to the address of a
7895 trampoline (passed as <tt>tramp</tt>).</p>
7896
7897<h5>Arguments:</h5>
7898<p><tt>tramp</tt> must point to a block of memory which already has trampoline code
7899 filled in by a previous call to <a href="#int_it"><tt>llvm.init.trampoline</tt>
7900 </a>.</p>
7901
7902<h5>Semantics:</h5>
7903<p>On some architectures the address of the code to be executed needs to be
7904 different to the address where the trampoline is actually stored. This
7905 intrinsic returns the executable address corresponding to <tt>tramp</tt>
7906 after performing the required machine specific adjustments.
7907 The pointer returned can then be <a href="#int_trampoline"> bitcast and
7908 executed</a>.
7909</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7910
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7911</div>
7912
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7913</div>
7914
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7915<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7916<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7917 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7918</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7919
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7920<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7921
7922<p>This class of intrinsics exists to information about the lifetime of memory
7923 objects and ranges where variables are immutable.</p>
7924
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7925<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7926<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7927 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7928</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7929
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7930<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7931
7932<h5>Syntax:</h5>
7933<pre>
7934 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7935</pre>
7936
7937<h5>Overview:</h5>
7938<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7939 object's lifetime.</p>
7940
7941<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7942<p>The first argument is a constant integer representing the size of the
7943 object, or -1 if it is variable sized. The second argument is a pointer to
7944 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7945
7946<h5>Semantics:</h5>
7947<p>This intrinsic indicates that before this point in the code, the value of the
7948 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]7949 never be used and has an undefined value. A load from the pointer that
7950 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7951 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7952
7953</div>
7954
7955<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7956<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7957 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7958</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7959
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7960<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7961
7962<h5>Syntax:</h5>
7963<pre>
7964 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7965</pre>
7966
7967<h5>Overview:</h5>
7968<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7969 object's lifetime.</p>
7970
7971<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7972<p>The first argument is a constant integer representing the size of the
7973 object, or -1 if it is variable sized. The second argument is a pointer to
7974 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7975
7976<h5>Semantics:</h5>
7977<p>This intrinsic indicates that after this point in the code, the value of the
7978 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7979 never be used and has an undefined value. Any stores into the memory object
7980 following this intrinsic may be removed as dead.
7981
7982</div>
7983
7984<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7985<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7986 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7987</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7988
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7989<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7990
7991<h5>Syntax:</h5>
7992<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]7993 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7994</pre>
7995
7996<h5>Overview:</h5>
7997<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7998 a memory object will not change.</p>
7999
8000<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8001<p>The first argument is a constant integer representing the size of the
8002 object, or -1 if it is variable sized. The second argument is a pointer to
8003 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8004
8005<h5>Semantics:</h5>
8006<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8007 the return value, the referenced memory location is constant and
8008 unchanging.</p>
8009
8010</div>
8011
8012<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8013<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8014 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8015</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8016
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8017<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8018
8019<h5>Syntax:</h5>
8020<pre>
8021 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8022</pre>
8023
8024<h5>Overview:</h5>
8025<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8026 a memory object are mutable.</p>
8027
8028<h5>Arguments:</h5>
8029<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8030 The second argument is a constant integer representing the size of the
8031 object, or -1 if it is variable sized and the third argument is a pointer
8032 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8033
8034<h5>Semantics:</h5>
8035<p>This intrinsic indicates that the memory is mutable again.</p>
8036
8037</div>
8038
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8039</div>
8040
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8041<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8042<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8043 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8044</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8045
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8046<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8047
8048<p>This class of intrinsics is designed to be generic and has no specific
8049 purpose.</p>
8050
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8051<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8052<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8053 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8054</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8055
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8056<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8057
8058<h5>Syntax:</h5>
8059<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8060 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]8061</pre>
8062
8063<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8064<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8065
8066<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8067<p>The first argument is a pointer to a value, the second is a pointer to a
8068 global string, the third is a pointer to a global string which is the source
8069 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8070
8071<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8072<p>This intrinsic allows annotation of local variables with arbitrary strings.
8073 This can be useful for special purpose optimizations that want to look for
John Criswelle865c032011-08-19 16:57:55 +0000[diff] [blame]8074 these annotations. These have no other defined use; they are ignored by code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8075 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8076
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8077</div>
8078
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8079<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8080<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8081 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8082</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8083
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8084<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8085
8086<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8087<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8088 any integer bit width.</p>
8089
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8090<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8091 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8092 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8093 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8094 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8095 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]8096</pre>
8097
8098<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8099<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8100
8101<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8102<p>The first argument is an integer value (result of some expression), the
8103 second is a pointer to a global string, the third is a pointer to a global
8104 string which is the source file name, and the last argument is the line
8105 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8106
8107<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8108<p>This intrinsic allows annotations to be put on arbitrary expressions with
8109 arbitrary strings. This can be useful for special purpose optimizations that
John Criswelle865c032011-08-19 16:57:55 +0000[diff] [blame]8110 want to look for these annotations. These have no other defined use; they
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8111 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8112
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8113</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8114
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8115<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8116<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8117 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8118</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8119
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8120<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8121
8122<h5>Syntax:</h5>
8123<pre>
8124 declare void @llvm.trap()
8125</pre>
8126
8127<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8128<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8129
8130<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8131<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8132
8133<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8134<p>This intrinsics is lowered to the target dependent trap instruction. If the
8135 target does not have a trap instruction, this intrinsic will be lowered to
8136 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8137
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8138</div>
8139
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8140<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8141<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8142 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8143</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8144
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8145<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8146
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8147<h5>Syntax:</h5>
8148<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8149 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8150</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8151
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8152<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8153<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8154 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8155 ensure that it is placed on the stack before local variables.</p>
8156
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8157<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8158<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8159 arguments. The first argument is the value loaded from the stack
8160 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8161 that has enough space to hold the value of the guard.</p>
8162
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8163<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8164<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8165 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8166 stack. This is to ensure that if a local variable on the stack is
8167 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8168 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8169 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8170 function.</p>
8171
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8172</div>
8173
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8174<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8175<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8176 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8177</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8178
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8179<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8180
8181<h5>Syntax:</h5>
8182<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8183 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8184 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8185</pre>
8186
8187<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8188<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8189 the optimizers to determine at compile time whether a) an operation (like
8190 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8191 runtime check for overflow isn't necessary. An object in this context means
8192 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8193
8194<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8195<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8196 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8197 is a boolean 0 or 1. This argument determines whether you want the
8198 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]8199 1, variables are not allowed.</p>
8200
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8201<h5>Semantics:</h5>
8202<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8203 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8204 depending on the <tt>type</tt> argument, if the size cannot be determined at
8205 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8206
8207</div>
8208
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8209</div>
8210
8211</div>
8212
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8213<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8214<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8215<address>
8216 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8217 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8218 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8219 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]8220
8221 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8222 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8223 Last modified: $Date$
8224</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8225
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8226</body>
8227</html>