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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 0b0669a0568331122e545c93c6580786cf0cafdd / . / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]58 <li><a href="#typesystem">Type System</a>
59 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]61 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]62 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]63 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]64 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]65 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_void">Void Type</a></li>
67 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]68 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 </ol>
70 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]71 <li><a href="#t_derived">Derived Types</a>
72 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]73 <li><a href="#t_aggregate">Aggregate Types</a>
74 <ol>
75 <li><a href="#t_array">Array Type</a></li>
76 <li><a href="#t_struct">Structure Type</a></li>
77 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]78 <li><a href="#t_vector">Vector Type</a></li>
79 </ol>
80 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#t_function">Function Type</a></li>
82 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]83 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]86 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]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>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]127 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]130 <li><a href="#binaryops">Binary Operations</a>
131 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]136 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]137 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]138 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
139 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
140 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]141 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
142 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
143 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]146 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
147 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]148 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
149 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
150 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]152 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]153 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]156 <li><a href="#vectorops">Vector Operations</a>
157 <ol>
158 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
159 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
160 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]161 </ol>
162 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]163 <li><a href="#aggregateops">Aggregate Operations</a>
164 <ol>
165 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
166 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
167 </ol>
168 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]169 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]170 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
174 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]175 </ol>
176 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]177 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]178 <ol>
179 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
180 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]184 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
186 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
187 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]188 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
189 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]190 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]191 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]192 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]193 <li><a href="#otherops">Other Operations</a>
194 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]195 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
196 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]198 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]199 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]200 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]203 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]204 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]205 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]206 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]207 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
208 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]209 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
211 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]214 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
215 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]216 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
218 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]221 <li><a href="#int_codegen">Code Generator Intrinsics</a>
222 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
225 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
226 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
227 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
228 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]229 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]230 </ol>
231 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]232 <li><a href="#int_libc">Standard C Library Intrinsics</a>
233 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]234 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]239 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]242 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]244 </ol>
245 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]246 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]247 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]248 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]249 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]252 </ol>
253 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]254 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
255 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]256 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
260 <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]261 <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]262 </ol>
263 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]264 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
265 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]266 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
267 <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]268 </ol>
269 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]270 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]271 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]272 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]273 <ol>
274 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]275 </ol>
276 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]277 <li><a href="#int_atomics">Atomic intrinsics</a>
278 <ol>
279 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
280 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
281 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
282 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
283 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
284 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
285 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
286 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
287 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
288 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
289 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
290 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
291 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
292 </ol>
293 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]294 <li><a href="#int_memorymarkers">Memory Use Markers</a>
295 <ol>
296 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
297 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
298 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
299 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
300 </ol>
301 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]303 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]306 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]308 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.trap</tt>' Intrinsic</a></li>
310 <li><a href="#int_stackprotector">
311 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]312 <li><a href="#int_objectsize">
313 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]314 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]315 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]316 </ol>
317 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]318</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]319
320<div class="doc_author">
321 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
322 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]323</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]326<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]328
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]329<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]330
331<p>This document is a reference manual for the LLVM assembly language. LLVM is
332 a Static Single Assignment (SSA) based representation that provides type
333 safety, low-level operations, flexibility, and the capability of representing
334 'all' high-level languages cleanly. It is the common code representation
335 used throughout all phases of the LLVM compilation strategy.</p>
336
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]337</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]338
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]339<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]340<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]341<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]343<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]344
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]345<p>The LLVM code representation is designed to be used in three different forms:
346 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
347 for fast loading by a Just-In-Time compiler), and as a human readable
348 assembly language representation. This allows LLVM to provide a powerful
349 intermediate representation for efficient compiler transformations and
350 analysis, while providing a natural means to debug and visualize the
351 transformations. The three different forms of LLVM are all equivalent. This
352 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]354<p>The LLVM representation aims to be light-weight and low-level while being
355 expressive, typed, and extensible at the same time. It aims to be a
356 "universal IR" of sorts, by being at a low enough level that high-level ideas
357 may be cleanly mapped to it (similar to how microprocessors are "universal
358 IR's", allowing many source languages to be mapped to them). By providing
359 type information, LLVM can be used as the target of optimizations: for
360 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]361 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]362 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]364<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]365<h4>
366 <a name="wellformed">Well-Formedness</a>
367</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]369<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]371<p>It is important to note that this document describes 'well formed' LLVM
372 assembly language. There is a difference between what the parser accepts and
373 what is considered 'well formed'. For example, the following instruction is
374 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]376<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]378</pre>
379
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]380<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
381 LLVM infrastructure provides a verification pass that may be used to verify
382 that an LLVM module is well formed. This pass is automatically run by the
383 parser after parsing input assembly and by the optimizer before it outputs
384 bitcode. The violations pointed out by the verifier pass indicate bugs in
385 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]386
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]388
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]389</div>
390
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]391<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]393<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]394<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]395<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]397<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]398
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]399<p>LLVM identifiers come in two basic types: global and local. Global
400 identifiers (functions, global variables) begin with the <tt>'@'</tt>
401 character. Local identifiers (register names, types) begin with
402 the <tt>'%'</tt> character. Additionally, there are three different formats
403 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]404
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]405<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]406 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]407 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
408 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
409 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
410 other characters in their names can be surrounded with quotes. Special
411 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
412 ASCII code for the character in hexadecimal. In this way, any character
413 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]414
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]415 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]416 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]418 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]419 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]422<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]423 don't need to worry about name clashes with reserved words, and the set of
424 reserved words may be expanded in the future without penalty. Additionally,
425 unnamed identifiers allow a compiler to quickly come up with a temporary
426 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]428<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]429 languages. There are keywords for different opcodes
430 ('<tt><a href="#i_add">add</a></tt>',
431 '<tt><a href="#i_bitcast">bitcast</a></tt>',
432 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
433 ('<tt><a href="#t_void">void</a></tt>',
434 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
435 reserved words cannot conflict with variable names, because none of them
436 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437
438<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]439 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]441<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]443<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]444%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445</pre>
446
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]447<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]453<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]456%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
457%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]458%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459</pre>
460
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]461<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
462 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]475 demonstrating instructions, we will follow an instruction with a comment that
476 defines the type and name of value produced. Comments are shown in italic
477 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]482<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]484<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]485<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]486<h3>
487 <a name="modulestructure">Module Structure</a>
488</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]489
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]492<p>LLVM programs are composed of "Module"s, each of which is a translation unit
493 of the input programs. Each module consists of functions, global variables,
494 and symbol table entries. Modules may be combined together with the LLVM
495 linker, which merges function (and global variable) definitions, resolves
496 forward declarations, and merges symbol table entries. Here is an example of
497 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]498
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]499<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]500<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]501<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]502
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]503<i>; External declaration of the puts function</i>&nbsp;
504<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>&nbsp;
508 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
509 %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]510
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
512 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
513 <a href="#i_ret">ret</a> i32 0&nbsp;
514}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]515
516<i>; Named metadata</i>
517!1 = metadata !{i32 41}
518!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]519</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]521<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]527<p>In general, a module is made up of a list of global values, where both
528 functions and global variables are global values. Global values are
529 represented by a pointer to a memory location (in this case, a pointer to an
530 array of char, and a pointer to a function), and have one of the
531 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]536<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]538</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]539
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]540<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]541
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]547 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
548 by objects in the current module. In particular, linking code into a
549 module with an private global value may cause the private to be renamed as
550 necessary to avoid collisions. Because the symbol is private to the
551 module, all references can be updated. This doesn't show up in any symbol
552 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]555 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
556 assembler and evaluated by the linker. Unlike normal strong symbols, they
557 are removed by the linker from the final linked image (executable or
558 dynamic library).</dd>
559
560 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
561 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
562 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
563 linker. The symbols are removed by the linker from the final linked image
564 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]565
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]566 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
568 of the object is not taken. For instance, functions that had an inline
569 definition, but the compiler decided not to inline it. Note,
570 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
571 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
572 visibility. The symbols are removed by the linker from the final linked
573 image (executable or dynamic library).</dd>
574
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]576 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]577 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
578 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]579
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]581 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]582 into the object file corresponding to the LLVM module. They exist to
583 allow inlining and other optimizations to take place given knowledge of
584 the definition of the global, which is known to be somewhere outside the
585 module. Globals with <tt>available_externally</tt> linkage are allowed to
586 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
587 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]588
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]590 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]591 the same name when linkage occurs. This can be used to implement
592 some forms of inline functions, templates, or other code which must be
593 generated in each translation unit that uses it, but where the body may
594 be overridden with a more definitive definition later. Unreferenced
595 <tt>linkonce</tt> globals are allowed to be discarded. Note that
596 <tt>linkonce</tt> linkage does not actually allow the optimizer to
597 inline the body of this function into callers because it doesn't know if
598 this definition of the function is the definitive definition within the
599 program or whether it will be overridden by a stronger definition.
600 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
601 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]602
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]603 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]604 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
605 <tt>linkonce</tt> linkage, except that unreferenced globals with
606 <tt>weak</tt> linkage may not be discarded. This is used for globals that
607 are declared "weak" in C source code.</dd>
608
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
611 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
612 global scope.
613 Symbols with "<tt>common</tt>" linkage are merged in the same way as
614 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]615 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]616 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]617 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
618 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]619
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]620
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]621 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]622 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]623 pointer to array type. When two global variables with appending linkage
624 are linked together, the two global arrays are appended together. This is
625 the LLVM, typesafe, equivalent of having the system linker append together
626 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]627
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]629 <dd>The semantics of this linkage follow the ELF object file model: the symbol
630 is weak until linked, if not linked, the symbol becomes null instead of
631 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]632
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
634 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]635 <dd>Some languages allow differing globals to be merged, such as two functions
636 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]637 that only equivalent globals are ever merged (the "one definition rule"
638 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]639 and <tt>weak_odr</tt> linkage types to indicate that the global will only
640 be merged with equivalent globals. These linkage types are otherwise the
641 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]642
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]644 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]645 visible, meaning that it participates in linkage and can be used to
646 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]647</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]648
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]649<p>The next two types of linkage are targeted for Microsoft Windows platform
650 only. They are designed to support importing (exporting) symbols from (to)
651 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]653<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]654 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]655 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656 or variable via a global pointer to a pointer that is set up by the DLL
657 exporting the symbol. On Microsoft Windows targets, the pointer name is
658 formed by combining <code>__imp_</code> and the function or variable
659 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]660
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]661 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]662 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]663 pointer to a pointer in a DLL, so that it can be referenced with the
664 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
665 name is formed by combining <code>__imp_</code> and the function or
666 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]667</dl>
668
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]669<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
670 another module defined a "<tt>.LC0</tt>" variable and was linked with this
671 one, one of the two would be renamed, preventing a collision. Since
672 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
673 declarations), they are accessible outside of the current module.</p>
674
675<p>It is illegal for a function <i>declaration</i> to have any linkage type
676 other than "externally visible", <tt>dllimport</tt>
677 or <tt>extern_weak</tt>.</p>
678
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]679<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]680 or <tt>weak_odr</tt> linkages.</p>
681
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]682</div>
683
684<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]685<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]687</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]688
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]689<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]690
691<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]692 and <a href="#i_invoke">invokes</a> can all have an optional calling
693 convention specified for the call. The calling convention of any pair of
694 dynamic caller/callee must match, or the behavior of the program is
695 undefined. The following calling conventions are supported by LLVM, and more
696 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]697
698<dl>
699 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]700 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]701 specified) matches the target C calling conventions. This calling
702 convention supports varargs function calls and tolerates some mismatch in
703 the declared prototype and implemented declaration of the function (as
704 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]708 (e.g. by passing things in registers). This calling convention allows the
709 target to use whatever tricks it wants to produce fast code for the
710 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]711 (Application Binary Interface).
712 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]713 when this or the GHC convention is used.</a> This calling convention
714 does not support varargs and requires the prototype of all callees to
715 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]716
717 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]718 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]719 as possible under the assumption that the call is not commonly executed.
720 As such, these calls often preserve all registers so that the call does
721 not break any live ranges in the caller side. This calling convention
722 does not support varargs and requires the prototype of all callees to
723 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]724
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]725 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
726 <dd>This calling convention has been implemented specifically for use by the
727 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
728 It passes everything in registers, going to extremes to achieve this by
729 disabling callee save registers. This calling convention should not be
730 used lightly but only for specific situations such as an alternative to
731 the <em>register pinning</em> performance technique often used when
732 implementing functional programming languages.At the moment only X86
733 supports this convention and it has the following limitations:
734 <ul>
735 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
736 floating point types are supported.</li>
737 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
738 6 floating point parameters.</li>
739 </ul>
740 This calling convention supports
741 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
742 requires both the caller and callee are using it.
743 </dd>
744
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]745 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]746 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]747 target-specific calling conventions to be used. Target specific calling
748 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]749</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]750
751<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]752 support Pascal conventions or any other well-known target-independent
753 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]754
755</div>
756
757<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]758<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]759 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]760</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]761
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]762<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]763
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]764<p>All Global Variables and Functions have one of the following visibility
765 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]766
767<dl>
768 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]769 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]770 that the declaration is visible to other modules and, in shared libraries,
771 means that the declared entity may be overridden. On Darwin, default
772 visibility means that the declaration is visible to other modules. Default
773 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]774
775 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]776 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]777 object if they are in the same shared object. Usually, hidden visibility
778 indicates that the symbol will not be placed into the dynamic symbol
779 table, so no other module (executable or shared library) can reference it
780 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]781
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]782 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]783 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]784 the dynamic symbol table, but that references within the defining module
785 will bind to the local symbol. That is, the symbol cannot be overridden by
786 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]787</dl>
788
789</div>
790
791<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]792<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]793 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]794</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]795
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]796<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]797
798<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]799 it easier to read the IR and make the IR more condensed (particularly when
800 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]801
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]802<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]803%mytype = type { %mytype*, i32 }
804</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]805
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]806<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]807 "<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]808 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]809
810<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]811 and that you can therefore specify multiple names for the same type. This
812 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
813 uses structural typing, the name is not part of the type. When printing out
814 LLVM IR, the printer will pick <em>one name</em> to render all types of a
815 particular shape. This means that if you have code where two different
816 source types end up having the same LLVM type, that the dumper will sometimes
817 print the "wrong" or unexpected type. This is an important design point and
818 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]819
820</div>
821
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]822<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]823<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]824 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]825</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]826
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]827<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]828
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]829<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]830 instead of run-time. Global variables may optionally be initialized, may
831 have an explicit section to be placed in, and may have an optional explicit
832 alignment specified. A variable may be defined as "thread_local", which
833 means that it will not be shared by threads (each thread will have a
834 separated copy of the variable). A variable may be defined as a global
835 "constant," which indicates that the contents of the variable
836 will <b>never</b> be modified (enabling better optimization, allowing the
837 global data to be placed in the read-only section of an executable, etc).
838 Note that variables that need runtime initialization cannot be marked
839 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]840
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]841<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
842 constant, even if the final definition of the global is not. This capability
843 can be used to enable slightly better optimization of the program, but
844 requires the language definition to guarantee that optimizations based on the
845 'constantness' are valid for the translation units that do not include the
846 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]847
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]848<p>As SSA values, global variables define pointer values that are in scope
849 (i.e. they dominate) all basic blocks in the program. Global variables
850 always define a pointer to their "content" type because they describe a
851 region of memory, and all memory objects in LLVM are accessed through
852 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]853
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]854<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
855 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]856 like this can be merged with other constants if they have the same
857 initializer. Note that a constant with significant address <em>can</em>
858 be merged with a <tt>unnamed_addr</tt> constant, the result being a
859 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]860
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]861<p>A global variable may be declared to reside in a target-specific numbered
862 address space. For targets that support them, address spaces may affect how
863 optimizations are performed and/or what target instructions are used to
864 access the variable. The default address space is zero. The address space
865 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]866
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]867<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]868 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]869
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]870<p>An explicit alignment may be specified for a global, which must be a power
871 of 2. If not present, or if the alignment is set to zero, the alignment of
872 the global is set by the target to whatever it feels convenient. If an
873 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]874 alignment. Targets and optimizers are not allowed to over-align the global
875 if the global has an assigned section. In this case, the extra alignment
876 could be observable: for example, code could assume that the globals are
877 densely packed in their section and try to iterate over them as an array,
878 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]879
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]880<p>For example, the following defines a global in a numbered address space with
881 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]882
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]883<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]884@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]885</pre>
886
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]887</div>
888
889
890<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]891<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]892 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]893</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]894
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]895<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]896
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]897<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]898 optional <a href="#linkage">linkage type</a>, an optional
899 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]900 <a href="#callingconv">calling convention</a>,
901 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]902 <a href="#paramattrs">parameter attribute</a> for the return type, a function
903 name, a (possibly empty) argument list (each with optional
904 <a href="#paramattrs">parameter attributes</a>), optional
905 <a href="#fnattrs">function attributes</a>, an optional section, an optional
906 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
907 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]908
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]909<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
910 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]911 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]912 <a href="#callingconv">calling convention</a>,
913 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]914 <a href="#paramattrs">parameter attribute</a> for the return type, a function
915 name, a possibly empty list of arguments, an optional alignment, and an
916 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]917
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]918<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]919 (Control Flow Graph) for the function. Each basic block may optionally start
920 with a label (giving the basic block a symbol table entry), contains a list
921 of instructions, and ends with a <a href="#terminators">terminator</a>
922 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]924<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]925 executed on entrance to the function, and it is not allowed to have
926 predecessor basic blocks (i.e. there can not be any branches to the entry
927 block of a function). Because the block can have no predecessors, it also
928 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]930<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]931 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]932
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]933<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]934 the alignment is set to zero, the alignment of the function is set by the
935 target to whatever it feels convenient. If an explicit alignment is
936 specified, the function is forced to have at least that much alignment. All
937 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]938
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]939<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
940 be significant and two identical functions can be merged</p>.
941
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]943<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]944define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]945 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
946 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
947 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
948 [<a href="#gc">gc</a>] { ... }
949</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]950
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]951</div>
952
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]953<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]954<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]955 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]956</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]957
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]958<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]959
960<p>Aliases act as "second name" for the aliasee value (which can be either
961 function, global variable, another alias or bitcast of global value). Aliases
962 may have an optional <a href="#linkage">linkage type</a>, and an
963 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]964
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]965<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]966<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]967@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]968</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]969
970</div>
971
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]972<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]973<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]974 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]975</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]976
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]977<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]978
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]979<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]980 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]981 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]982
983<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]984<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]985; Some unnamed metadata nodes, which are referenced by the named metadata.
986!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]987!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]988!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]989; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]990!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]991</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]992
993</div>
994
995<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]996<h3>
997 <a name="paramattrs">Parameter Attributes</a>
998</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]999
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1000<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1001
1002<p>The return type and each parameter of a function type may have a set of
1003 <i>parameter attributes</i> associated with them. Parameter attributes are
1004 used to communicate additional information about the result or parameters of
1005 a function. Parameter attributes are considered to be part of the function,
1006 not of the function type, so functions with different parameter attributes
1007 can have the same function type.</p>
1008
1009<p>Parameter attributes are simple keywords that follow the type specified. If
1010 multiple parameter attributes are needed, they are space separated. For
1011 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1012
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1013<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1014declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1015declare i32 @atoi(i8 zeroext)
1016declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1017</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1018
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1019<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1020 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1022<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1023
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1024<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1025 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1026 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1027 should be zero-extended to the extent required by the target's ABI (which
1028 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1029 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1030
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1033 should be sign-extended to the extent required by the target's ABI (which
1034 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1035 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates that this parameter or return value should be treated in a
1039 special target-dependent fashion during while emitting code for a function
1040 call or return (usually, by putting it in a register as opposed to memory,
1041 though some targets use it to distinguish between two different kinds of
1042 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1043
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1045 <dd><p>This indicates that the pointer parameter should really be passed by
1046 value to the function. The attribute implies that a hidden copy of the
1047 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1048 is made between the caller and the callee, so the callee is unable to
1049 modify the value in the callee. This attribute is only valid on LLVM
1050 pointer arguments. It is generally used to pass structs and arrays by
1051 value, but is also valid on pointers to scalars. The copy is considered
1052 to belong to the caller not the callee (for example,
1053 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1054 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1055 values.</p>
1056
1057 <p>The byval attribute also supports specifying an alignment with
1058 the align attribute. It indicates the alignment of the stack slot to
1059 form and the known alignment of the pointer specified to the call site. If
1060 the alignment is not specified, then the code generator makes a
1061 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1062
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1063 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1064 <dd>This indicates that the pointer parameter specifies the address of a
1065 structure that is the return value of the function in the source program.
1066 This pointer must be guaranteed by the caller to be valid: loads and
1067 stores to the structure may be assumed by the callee to not to trap. This
1068 may only be applied to the first parameter. This is not a valid attribute
1069 for return values. </dd>
1070
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1071 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1072 <dd>This indicates that pointer values
1073 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1074 value do not alias pointer values which are not <i>based</i> on it,
1075 ignoring certain "irrelevant" dependencies.
1076 For a call to the parent function, dependencies between memory
1077 references from before or after the call and from those during the call
1078 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1079 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1080 The caller shares the responsibility with the callee for ensuring that
1081 these requirements are met.
1082 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1083 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1084<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1085 Note that this definition of <tt>noalias</tt> is intentionally
1086 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1087 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1088<br>
1089 For function return values, C99's <tt>restrict</tt> is not meaningful,
1090 while LLVM's <tt>noalias</tt> is.
1091 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1092
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1093 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1094 <dd>This indicates that the callee does not make any copies of the pointer
1095 that outlive the callee itself. This is not a valid attribute for return
1096 values.</dd>
1097
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the pointer parameter can be excised using the
1100 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1101 attribute for return values.</dd>
1102</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1103
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1104</div>
1105
1106<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1107<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1108 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1109</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1110
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1111<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1112
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1113<p>Each function may specify a garbage collector name, which is simply a
1114 string:</p>
1115
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1116<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1117define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1118</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1119
1120<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1121 collector which will cause the compiler to alter its output in order to
1122 support the named garbage collection algorithm.</p>
1123
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1124</div>
1125
1126<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1127<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1128 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1129</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1130
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1131<div>
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 set to communicate additional information about a
1134 function. Function attributes are considered to be part of the function, not
1135 of the function type, so functions with different parameter attributes can
1136 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are simple keywords that follow the type specified. If
1139 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1140
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1141<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1142define void @f() noinline { ... }
1143define void @f() alwaysinline { ... }
1144define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1145define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1146</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1147
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1148<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1149 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1150 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1151 the backend should forcibly align the stack pointer. Specify the
1152 desired alignment, which must be a power of two, in parentheses.
1153
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the inliner should attempt to inline this
1156 function into callers whenever possible, ignoring any active inlining size
1157 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1158
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1159 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1160 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1161 meaning the function can be patched and/or hooked even while it is
1162 loaded into memory. On x86, the function prologue will be preceded
1163 by six bytes of padding and will begin with a two-byte instruction.
1164 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1165 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1166
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1167 <dt><tt><b>nonlazybind</b></tt></dt>
1168 <dd>This attribute suppresses lazy symbol binding for the function. This
1169 may make calls to the function faster, at the cost of extra program
1170 startup time if the function is not called during program startup.</dd>
1171
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1172 <dt><tt><b>inlinehint</b></tt></dt>
1173 <dd>This attribute indicates that the source code contained a hint that inlining
1174 this function is desirable (such as the "inline" keyword in C/C++). It
1175 is just a hint; it imposes no requirements on the inliner.</dd>
1176
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1177 <dt><tt><b>naked</b></tt></dt>
1178 <dd>This attribute disables prologue / epilogue emission for the function.
1179 This can have very system-specific consequences.</dd>
1180
1181 <dt><tt><b>noimplicitfloat</b></tt></dt>
1182 <dd>This attributes disables implicit floating point instructions.</dd>
1183
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1184 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1185 <dd>This attribute indicates that the inliner should never inline this
1186 function in any situation. This attribute may not be used together with
1187 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1188
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1189 <dt><tt><b>noredzone</b></tt></dt>
1190 <dd>This attribute indicates that the code generator should not use a red
1191 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1192
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1194 <dd>This function attribute indicates that the function never returns
1195 normally. This produces undefined behavior at runtime if the function
1196 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1197
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns with an
1200 unwind or exceptional control flow. If the function does unwind, its
1201 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1202
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1203 <dt><tt><b>optsize</b></tt></dt>
1204 <dd>This attribute suggests that optimization passes and code generator passes
1205 make choices that keep the code size of this function low, and otherwise
1206 do optimizations specifically to reduce code size.</dd>
1207
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1208 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1209 <dd>This attribute indicates that the function computes its result (or decides
1210 to unwind an exception) based strictly on its arguments, without
1211 dereferencing any pointer arguments or otherwise accessing any mutable
1212 state (e.g. memory, control registers, etc) visible to caller functions.
1213 It does not write through any pointer arguments
1214 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1215 changes any state visible to callers. This means that it cannot unwind
1216 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1217 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1218
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1219 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1220 <dd>This attribute indicates that the function does not write through any
1221 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1222 arguments) or otherwise modify any state (e.g. memory, control registers,
1223 etc) visible to caller functions. It may dereference pointer arguments
1224 and read state that may be set in the caller. A readonly function always
1225 returns the same value (or unwinds an exception identically) when called
1226 with the same set of arguments and global state. It cannot unwind an
1227 exception by calling the <tt>C++</tt> exception throwing methods, but may
1228 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1229
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1230 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1231 <dd>This attribute indicates that the function should emit a stack smashing
1232 protector. It is in the form of a "canary"&mdash;a random value placed on
1233 the stack before the local variables that's checked upon return from the
1234 function to see if it has been overwritten. A heuristic is used to
1235 determine if a function needs stack protectors or not.<br>
1236<br>
1237 If a function that has an <tt>ssp</tt> attribute is inlined into a
1238 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1239 function will have an <tt>ssp</tt> attribute.</dd>
1240
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1241 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1242 <dd>This attribute indicates that the function should <em>always</em> emit a
1243 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1244 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1245<br>
1246 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1247 function that doesn't have an <tt>sspreq</tt> attribute or which has
1248 an <tt>ssp</tt> attribute, then the resulting function will have
1249 an <tt>sspreq</tt> attribute.</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
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1310 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1311 <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]1312 <i>preferred</i> alignments. All sizes are in bits. Specifying
1313 the <i>pref</i> alignment is optional. If omitted, the
1314 preceding <tt>:</tt> should be omitted too.</dd>
1315
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1316 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1317 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1318 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1319
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1320 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1321 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1322 <i>size</i>.</dd>
1323
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1325 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1326 <i>size</i>. Only values of <i>size</i> that are supported by the target
1327 will work. 32 (float) and 64 (double) are supported on all targets;
1328 80 or 128 (different flavors of long double) are also supported on some
1329 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1330
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1331 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1332 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1333 <i>size</i>.</dd>
1334
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1335 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1336 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1337 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1338
1339 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1340 <dd>This specifies a set of native integer widths for the target CPU
1341 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1342 "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]1343 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1344 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1345</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1346
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1347<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1348 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1349 specifications in the <tt>datalayout</tt> keyword. The default specifications
1350 are given in this list:</p>
1351
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1352<ul>
1353 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1354 <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]1355 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1356 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1357 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1358 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1359 <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]1360 alignment of 64-bits</li>
1361 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1362 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1363 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1364 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1365 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1366 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1367</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1368
1369<p>When LLVM is determining the alignment for a given type, it uses the
1370 following rules:</p>
1371
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1372<ol>
1373 <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]1374 specification is used.</li>
1375
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1376 <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]1377 smallest integer type that is larger than the bitwidth of the sought type
1378 is used. If none of the specifications are larger than the bitwidth then
1379 the the largest integer type is used. For example, given the default
1380 specifications above, the i7 type will use the alignment of i8 (next
1381 largest) while both i65 and i256 will use the alignment of i64 (largest
1382 specified).</li>
1383
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1384 <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]1385 largest vector type that is smaller than the sought vector type will be
1386 used as a fall back. This happens because &lt;128 x double&gt; can be
1387 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1388</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1389
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1390</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1391
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1392<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1393<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1394 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1395</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1397<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1398
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1399<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1400with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1401is undefined. Pointer values are associated with address ranges
1402according to the following rules:</p>
1403
1404<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1405 <li>A pointer value is associated with the addresses associated with
1406 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1407 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1408 range of the variable's storage.</li>
1409 <li>The result value of an allocation instruction is associated with
1410 the address range of the allocated storage.</li>
1411 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1412 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1413 <li>An integer constant other than zero or a pointer value returned
1414 from a function not defined within LLVM may be associated with address
1415 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1416 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1417 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1418</ul>
1419
1420<p>A pointer value is <i>based</i> on another pointer value according
1421 to the following rules:</p>
1422
1423<ul>
1424 <li>A pointer value formed from a
1425 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1426 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1427 <li>The result value of a
1428 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1429 of the <tt>bitcast</tt>.</li>
1430 <li>A pointer value formed by an
1431 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1432 pointer values that contribute (directly or indirectly) to the
1433 computation of the pointer's value.</li>
1434 <li>The "<i>based</i> on" relationship is transitive.</li>
1435</ul>
1436
1437<p>Note that this definition of <i>"based"</i> is intentionally
1438 similar to the definition of <i>"based"</i> in C99, though it is
1439 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1440
1441<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1442<tt><a href="#i_load">load</a></tt> merely indicates the size and
1443alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1444interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1445<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1446and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1447
1448<p>Consequently, type-based alias analysis, aka TBAA, aka
1449<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1450LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1451additional information which specialized optimization passes may use
1452to implement type-based alias analysis.</p>
1453
1454</div>
1455
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1456<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1457<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1458 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1459</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1460
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1461<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1462
1463<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1464href="#i_store"><tt>store</tt></a>s, and <a
1465href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1466The optimizers must not change the number of volatile operations or change their
1467order of execution relative to other volatile operations. The optimizers
1468<i>may</i> change the order of volatile operations relative to non-volatile
1469operations. This is not Java's "volatile" and has no cross-thread
1470synchronization behavior.</p>
1471
1472</div>
1473
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1474</div>
1475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1476<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1477<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1478<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1480<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1481
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1482<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1483 intermediate representation. Being typed enables a number of optimizations
1484 to be performed on the intermediate representation directly, without having
1485 to do extra analyses on the side before the transformation. A strong type
1486 system makes it easier to read the generated code and enables novel analyses
1487 and transformations that are not feasible to perform on normal three address
1488 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1489
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1490<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1491<h3>
1492 <a name="t_classifications">Type Classifications</a>
1493</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1494
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1495<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1496
1497<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1498
1499<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1500 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1501 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1502 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1503 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1504 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1505 </tr>
1506 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1507 <td><a href="#t_floating">floating point</a></td>
1508 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1509 </tr>
1510 <tr>
1511 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1512 <td><a href="#t_integer">integer</a>,
1513 <a href="#t_floating">floating point</a>,
1514 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1515 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1516 <a href="#t_struct">structure</a>,
1517 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1518 <a href="#t_label">label</a>,
1519 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1520 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1521 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1522 <tr>
1523 <td><a href="#t_primitive">primitive</a></td>
1524 <td><a href="#t_label">label</a>,
1525 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1526 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1527 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1528 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1529 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1530 </tr>
1531 <tr>
1532 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1533 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1534 <a href="#t_function">function</a>,
1535 <a href="#t_pointer">pointer</a>,
1536 <a href="#t_struct">structure</a>,
1537 <a href="#t_pstruct">packed structure</a>,
1538 <a href="#t_vector">vector</a>,
1539 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1540 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1541 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1542 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1543</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1544
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1545<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1546 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1547 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1548
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1549</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1550
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1551<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1552<h3>
1553 <a name="t_primitive">Primitive Types</a>
1554</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1555
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1556<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1557
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1558<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1559 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1560
1561<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1562<h4>
1563 <a name="t_integer">Integer Type</a>
1564</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1565
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1566<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1567
1568<h5>Overview:</h5>
1569<p>The integer type is a very simple type that simply specifies an arbitrary
1570 bit width for the integer type desired. Any bit width from 1 bit to
1571 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1572
1573<h5>Syntax:</h5>
1574<pre>
1575 iN
1576</pre>
1577
1578<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1579 value.</p>
1580
1581<h5>Examples:</h5>
1582<table class="layout">
1583 <tr class="layout">
1584 <td class="left"><tt>i1</tt></td>
1585 <td class="left">a single-bit integer.</td>
1586 </tr>
1587 <tr class="layout">
1588 <td class="left"><tt>i32</tt></td>
1589 <td class="left">a 32-bit integer.</td>
1590 </tr>
1591 <tr class="layout">
1592 <td class="left"><tt>i1942652</tt></td>
1593 <td class="left">a really big integer of over 1 million bits.</td>
1594 </tr>
1595</table>
1596
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1597</div>
1598
1599<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1600<h4>
1601 <a name="t_floating">Floating Point Types</a>
1602</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1603
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1604<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1605
1606<table>
1607 <tbody>
1608 <tr><th>Type</th><th>Description</th></tr>
1609 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1610 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1611 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1612 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1613 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1614 </tbody>
1615</table>
1616
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1617</div>
1618
1619<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1620<h4>
1621 <a name="t_x86mmx">X86mmx Type</a>
1622</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1623
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1624<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1625
1626<h5>Overview:</h5>
1627<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>
1628
1629<h5>Syntax:</h5>
1630<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1631 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1632</pre>
1633
1634</div>
1635
1636<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1637<h4>
1638 <a name="t_void">Void Type</a>
1639</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1640
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1641<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1642
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1643<h5>Overview:</h5>
1644<p>The void type does not represent any value and has no size.</p>
1645
1646<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1647<pre>
1648 void
1649</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1650
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1651</div>
1652
1653<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1654<h4>
1655 <a name="t_label">Label Type</a>
1656</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1657
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1658<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1659
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1660<h5>Overview:</h5>
1661<p>The label type represents code labels.</p>
1662
1663<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1664<pre>
1665 label
1666</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1667
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1668</div>
1669
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1670<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1671<h4>
1672 <a name="t_metadata">Metadata Type</a>
1673</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1674
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1675<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1676
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1677<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1678<p>The metadata type represents embedded metadata. No derived types may be
1679 created from metadata except for <a href="#t_function">function</a>
1680 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1681
1682<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1683<pre>
1684 metadata
1685</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1686
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1687</div>
1688
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1689</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1690
1691<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1692<h3>
1693 <a name="t_derived">Derived Types</a>
1694</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1695
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1696<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1697
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1698<p>The real power in LLVM comes from the derived types in the system. This is
1699 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1700 useful types. Each of these types contain one or more element types which
1701 may be a primitive type, or another derived type. For example, it is
1702 possible to have a two dimensional array, using an array as the element type
1703 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1704
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1705
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1706<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1707<h4>
1708 <a name="t_aggregate">Aggregate Types</a>
1709</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1710
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1711<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1712
1713<p>Aggregate Types are a subset of derived types that can contain multiple
1714 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1715 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1716 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1717
1718</div>
1719
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1720<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1721<h4>
1722 <a name="t_array">Array Type</a>
1723</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1724
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1725<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1727<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1728<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1729 sequentially in memory. The array type requires a size (number of elements)
1730 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1731
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1732<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1733<pre>
1734 [&lt;# elements&gt; x &lt;elementtype&gt;]
1735</pre>
1736
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1737<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1738 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1739
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1740<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1741<table class="layout">
1742 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1743 <td class="left"><tt>[40 x i32]</tt></td>
1744 <td class="left">Array of 40 32-bit integer values.</td>
1745 </tr>
1746 <tr class="layout">
1747 <td class="left"><tt>[41 x i32]</tt></td>
1748 <td class="left">Array of 41 32-bit integer values.</td>
1749 </tr>
1750 <tr class="layout">
1751 <td class="left"><tt>[4 x i8]</tt></td>
1752 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1753 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1754</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1755<p>Here are some examples of multidimensional arrays:</p>
1756<table class="layout">
1757 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1758 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1759 <td class="left">3x4 array of 32-bit integer values.</td>
1760 </tr>
1761 <tr class="layout">
1762 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1763 <td class="left">12x10 array of single precision floating point values.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1767 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1768 </tr>
1769</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1770
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1771<p>There is no restriction on indexing beyond the end of the array implied by
1772 a static type (though there are restrictions on indexing beyond the bounds
1773 of an allocated object in some cases). This means that single-dimension
1774 'variable sized array' addressing can be implemented in LLVM with a zero
1775 length array type. An implementation of 'pascal style arrays' in LLVM could
1776 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1777
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1778</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1780<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1781<h4>
1782 <a name="t_function">Function Type</a>
1783</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1784
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1785<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1787<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1788<p>The function type can be thought of as a function signature. It consists of
1789 a return type and a list of formal parameter types. The return type of a
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1790 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1791
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1792<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1793<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1794 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1795</pre>
1796
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1797<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1798 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1799 which indicates that the function takes a variable number of arguments.
1800 Variable argument functions can access their arguments with
1801 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1802 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1803 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1804
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1805<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1806<table class="layout">
1807 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1808 <td class="left"><tt>i32 (i32)</tt></td>
1809 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1810 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1811 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1812 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1813 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1814 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1815 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1816 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1817 </td>
1818 </tr><tr class="layout">
1819 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1820 <td class="left">A vararg function that takes at least one
1821 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1822 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1823 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1824 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1825 </tr><tr class="layout">
1826 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1827 <td class="left">A function taking an <tt>i32</tt>, returning a
1828 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1829 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1830 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1831</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1832
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1833</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1834
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1835<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1836<h4>
1837 <a name="t_struct">Structure Type</a>
1838</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1839
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1840<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1841
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1842<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1843<p>The structure type is used to represent a collection of data members together
1844 in memory. The packing of the field types is defined to match the ABI of the
1845 underlying processor. The elements of a structure may be any type that has a
1846 size.</p>
1847
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1848<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1849 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1850 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1851 Structures in registers are accessed using the
1852 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1853 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1854<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1855<pre>
1856 { &lt;type list&gt; }
1857</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1859<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1860<table class="layout">
1861 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1862 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1863 <td class="left">A triple of three <tt>i32</tt> values</td>
1864 </tr><tr class="layout">
1865 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1866 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1867 second element is a <a href="#t_pointer">pointer</a> to a
1868 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1869 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1870 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1871</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1872
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1873</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1874
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1875<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1876<h4>
1877 <a name="t_pstruct">Packed Structure Type</a>
1878</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1879
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1880<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1881
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1882<h5>Overview:</h5>
1883<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1884 together in memory. There is no padding between fields. Further, the
1885 alignment of a packed structure is 1 byte. The elements of a packed
1886 structure may be any type that has a size.</p>
1887
1888<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1889 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1890 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1891
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1892<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1893<pre>
1894 &lt; { &lt;type list&gt; } &gt;
1895</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1896
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1897<h5>Examples:</h5>
1898<table class="layout">
1899 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1900 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1901 <td class="left">A triple of three <tt>i32</tt> values</td>
1902 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1903 <td class="left">
1904<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1905 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1906 second element is a <a href="#t_pointer">pointer</a> to a
1907 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1908 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1909 </tr>
1910</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1911
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1912</div>
1913
1914<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1915<h4>
1916 <a name="t_pointer">Pointer Type</a>
1917</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1918
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1919<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1920
1921<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1922<p>The pointer type is used to specify memory locations.
1923 Pointers are commonly used to reference objects in memory.</p>
1924
1925<p>Pointer types may have an optional address space attribute defining the
1926 numbered address space where the pointed-to object resides. The default
1927 address space is number zero. The semantics of non-zero address
1928 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1929
1930<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1931 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1932
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1933<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1934<pre>
1935 &lt;type&gt; *
1936</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1938<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1939<table class="layout">
1940 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1941 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1942 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1943 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1944 </tr>
1945 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]1946 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1947 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1948 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1949 <tt>i32</tt>.</td>
1950 </tr>
1951 <tr class="layout">
1952 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1953 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1954 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1955 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1956</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1957
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1958</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1959
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1960<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1961<h4>
1962 <a name="t_vector">Vector Type</a>
1963</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1964
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1965<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1966
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1967<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1968<p>A vector type is a simple derived type that represents a vector of elements.
1969 Vector types are used when multiple primitive data are operated in parallel
1970 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1971 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1972 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1973
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1974<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1975<pre>
1976 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1977</pre>
1978
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]1979<p>The number of elements is a constant integer value larger than 0; elementtype
1980 may be any integer or floating point type. Vectors of size zero are not
1981 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1982
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1983<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1984<table class="layout">
1985 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1986 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1987 <td class="left">Vector of 4 32-bit integer values.</td>
1988 </tr>
1989 <tr class="layout">
1990 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1991 <td class="left">Vector of 8 32-bit floating-point values.</td>
1992 </tr>
1993 <tr class="layout">
1994 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1995 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1996 </tr>
1997</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1998
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1999</div>
2000
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2001<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2002<h4>
2003 <a name="t_opaque">Opaque Type</a>
2004</h4>
2005
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2006<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2007
2008<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2009<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2010 corresponds (for example) to the C notion of a forward declared structure
2011 type. In LLVM, opaque types can eventually be resolved to any type (not just
2012 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2013
2014<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2015<pre>
2016 opaque
2017</pre>
2018
2019<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2020<table class="layout">
2021 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2022 <td class="left"><tt>opaque</tt></td>
2023 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2024 </tr>
2025</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2026
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2027</div>
2028
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2029</div>
2030
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2031<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2032<h3>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2033 <a name="t_uprefs">Type Up-references</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2034</h3>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2035
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2036<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2037
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2038<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2039<p>An "up reference" allows you to refer to a lexically enclosing type without
2040 requiring it to have a name. For instance, a structure declaration may
2041 contain a pointer to any of the types it is lexically a member of. Example
2042 of up references (with their equivalent as named type declarations)
2043 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2044
2045<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]2046 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2047 { \2 }* %y = type { %y }*
2048 \1* %z = type %z*
2049</pre>
2050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2051<p>An up reference is needed by the asmprinter for printing out cyclic types
2052 when there is no declared name for a type in the cycle. Because the
2053 asmprinter does not want to print out an infinite type string, it needs a
2054 syntax to handle recursive types that have no names (all names are optional
2055 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2056
2057<h5>Syntax:</h5>
2058<pre>
2059 \&lt;level&gt;
2060</pre>
2061
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2062<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2063
2064<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2065<table class="layout">
2066 <tr class="layout">
2067 <td class="left"><tt>\1*</tt></td>
2068 <td class="left">Self-referential pointer.</td>
2069 </tr>
2070 <tr class="layout">
2071 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2072 <td class="left">Recursive structure where the upref refers to the out-most
2073 structure.</td>
2074 </tr>
2075</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2076
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2077</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2078
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2079</div>
2080
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2081<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2082<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2083<!-- *********************************************************************** -->
2084
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2085<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2086
2087<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2088 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2089
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2090<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2091<h3>
2092 <a name="simpleconstants">Simple Constants</a>
2093</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2094
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2095<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2096
2097<dl>
2098 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2099 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2100 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2101
2102 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2103 <dd>Standard integers (such as '4') are constants of
2104 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2105 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2106
2107 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2108 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2109 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2110 notation (see below). The assembler requires the exact decimal value of a
2111 floating-point constant. For example, the assembler accepts 1.25 but
2112 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2113 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2114
2115 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2116 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2117 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2118</dl>
2119
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2120<p>The one non-intuitive notation for constants is the hexadecimal form of
2121 floating point constants. For example, the form '<tt>double
2122 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2123 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2124 constants are required (and the only time that they are generated by the
2125 disassembler) is when a floating point constant must be emitted but it cannot
2126 be represented as a decimal floating point number in a reasonable number of
2127 digits. For example, NaN's, infinities, and other special values are
2128 represented in their IEEE hexadecimal format so that assembly and disassembly
2129 do not cause any bits to change in the constants.</p>
2130
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2131<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2132 represented using the 16-digit form shown above (which matches the IEEE754
2133 representation for double); float values must, however, be exactly
2134 representable as IEE754 single precision. Hexadecimal format is always used
2135 for long double, and there are three forms of long double. The 80-bit format
2136 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2137 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2138 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2139 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2140 currently supported target uses this format. Long doubles will only work if
2141 they match the long double format on your target. All hexadecimal formats
2142 are big-endian (sign bit at the left).</p>
2143
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2144<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2145</div>
2146
2147<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2148<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2149<a name="aggregateconstants"></a> <!-- old anchor -->
2150<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2151</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2152
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2153<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2154
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2155<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2156 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2157
2158<dl>
2159 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2160 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2161 type definitions (a comma separated list of elements, surrounded by braces
2162 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2163 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2164 Structure constants must have <a href="#t_struct">structure type</a>, and
2165 the number and types of elements must match those specified by the
2166 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2167
2168 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2169 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2170 definitions (a comma separated list of elements, surrounded by square
2171 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2172 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2173 the number and types of elements must match those specified by the
2174 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2175
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2176 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2177 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2178 definitions (a comma separated list of elements, surrounded by
2179 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2180 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2181 have <a href="#t_vector">vector type</a>, and the number and types of
2182 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2183
2184 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2185 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2186 value to zero of <em>any</em> type, including scalar and
2187 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2188 This is often used to avoid having to print large zero initializers
2189 (e.g. for large arrays) and is always exactly equivalent to using explicit
2190 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2191
2192 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2193 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2194 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2195 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2196 be interpreted as part of the instruction stream, metadata is a place to
2197 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2198</dl>
2199
2200</div>
2201
2202<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2203<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2204 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2205</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2206
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2207<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2208
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2209<p>The addresses of <a href="#globalvars">global variables</a>
2210 and <a href="#functionstructure">functions</a> are always implicitly valid
2211 (link-time) constants. These constants are explicitly referenced when
2212 the <a href="#identifiers">identifier for the global</a> is used and always
2213 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2214 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2215
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2216<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2217@X = global i32 17
2218@Y = global i32 42
2219@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2220</pre>
2221
2222</div>
2223
2224<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2225<h3>
2226 <a name="undefvalues">Undefined Values</a>
2227</h3>
2228
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2229<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2230
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2231<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]2232 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2233 Undefined values may be of any type (other than '<tt>label</tt>'
2234 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2235
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2236<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2237 program is well defined no matter what value is used. This gives the
2238 compiler more freedom to optimize. Here are some examples of (potentially
2239 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2240
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2241
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2242<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2243 %A = add %X, undef
2244 %B = sub %X, undef
2245 %C = xor %X, undef
2246Safe:
2247 %A = undef
2248 %B = undef
2249 %C = undef
2250</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2251
2252<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]2253 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]2254
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2255<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2256 %A = or %X, undef
2257 %B = and %X, undef
2258Safe:
2259 %A = -1
2260 %B = 0
2261Unsafe:
2262 %A = undef
2263 %B = undef
2264</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2265
2266<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2267 For example, if <tt>%X</tt> has a zero bit, then the output of the
2268 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2269 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2270 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2271 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2272 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2273 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2274 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2275
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2276<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2277 %A = select undef, %X, %Y
2278 %B = select undef, 42, %Y
2279 %C = select %X, %Y, undef
2280Safe:
2281 %A = %X (or %Y)
2282 %B = 42 (or %Y)
2283 %C = %Y
2284Unsafe:
2285 %A = undef
2286 %B = undef
2287 %C = undef
2288</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2289
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2290<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2291 branch) conditions can go <em>either way</em>, but they have to come from one
2292 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2293 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2294 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2295 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2296 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2297 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2298
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2299<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2300 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2301
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2302 %B = undef
2303 %C = xor %B, %B
2304
2305 %D = undef
2306 %E = icmp lt %D, 4
2307 %F = icmp gte %D, 4
2308
2309Safe:
2310 %A = undef
2311 %B = undef
2312 %C = undef
2313 %D = undef
2314 %E = undef
2315 %F = undef
2316</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2317
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2318<p>This example points out that two '<tt>undef</tt>' operands are not
2319 necessarily the same. This can be surprising to people (and also matches C
2320 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2321 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2322 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2323 its value over its "live range". This is true because the variable doesn't
2324 actually <em>have a live range</em>. Instead, the value is logically read
2325 from arbitrary registers that happen to be around when needed, so the value
2326 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2327 need to have the same semantics or the core LLVM "replace all uses with"
2328 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2329
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2330<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2331 %A = fdiv undef, %X
2332 %B = fdiv %X, undef
2333Safe:
2334 %A = undef
2335b: unreachable
2336</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2337
2338<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2339 value</em> and <em>undefined behavior</em>. An undefined value (like
2340 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2341 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2342 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2343 defined on SNaN's. However, in the second example, we can make a more
2344 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2345 arbitrary value, we are allowed to assume that it could be zero. Since a
2346 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2347 the operation does not execute at all. This allows us to delete the divide and
2348 all code after it. Because the undefined operation "can't happen", the
2349 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2350
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2351<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2352a: store undef -> %X
2353b: store %X -> undef
2354Safe:
2355a: &lt;deleted&gt;
2356b: unreachable
2357</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2358
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2359<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2360 undefined value can be assumed to not have any effect; we can assume that the
2361 value is overwritten with bits that happen to match what was already there.
2362 However, a store <em>to</em> an undefined location could clobber arbitrary
2363 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2364
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2365</div>
2366
2367<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2368<h3>
2369 <a name="trapvalues">Trap Values</a>
2370</h3>
2371
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2372<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2373
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2374<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2375 instead of representing an unspecified bit pattern, they represent the
2376 fact that an instruction or constant expression which cannot evoke side
2377 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2378 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2379
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2380<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]2381 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2382 <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]2383
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2384<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2385
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2386<ul>
2387<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2388 their operands.</li>
2389
2390<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2391 to their dynamic predecessor basic block.</li>
2392
2393<li>Function arguments depend on the corresponding actual argument values in
2394 the dynamic callers of their functions.</li>
2395
2396<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2397 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2398 control back to them.</li>
2399
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2400<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2401 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2402 or exception-throwing call instructions that dynamically transfer control
2403 back to them.</li>
2404
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2405<li>Non-volatile loads and stores depend on the most recent stores to all of the
2406 referenced memory addresses, following the order in the IR
2407 (including loads and stores implied by intrinsics such as
2408 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2409
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2410<!-- TODO: In the case of multiple threads, this only applies if the store
2411 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2412
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2413<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2414
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2415<li>An instruction with externally visible side effects depends on the most
2416 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2417 the order in the IR. (This includes
2418 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2419
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2420<li>An instruction <i>control-depends</i> on a
2421 <a href="#terminators">terminator instruction</a>
2422 if the terminator instruction has multiple successors and the instruction
2423 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2424 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2425
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2426<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2427 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2428 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2429 successor.</li>
2430
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2431<li>Dependence is transitive.</li>
2432
2433</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2434
2435<p>Whenever a trap value is generated, all values which depend on it evaluate
2436 to trap. If they have side effects, the evoke their side effects as if each
2437 operand with a trap value were undef. If they have externally-visible side
2438 effects, the behavior is undefined.</p>
2439
2440<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2441
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2442<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2443entry:
2444 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2445 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2446 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2447 store i32 0, i32* %trap_yet_again ; undefined behavior
2448
2449 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2450 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2451
2452 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2453
2454 %narrowaddr = bitcast i32* @g to i16*
2455 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2456 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2457 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2458
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2459 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2460 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2461
2462true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2463 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2464 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2465 br label %end
2466
2467end:
2468 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2469 ; Both edges into this PHI are
2470 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2471 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2472
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2473 volatile store i32 0, i32* @g ; This would depend on the store in %true
2474 ; if %cmp is true, or the store in %entry
2475 ; otherwise, so this is undefined behavior.
2476
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2477 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2478 ; The same branch again, but this time the
2479 ; true block doesn't have side effects.
2480
2481second_true:
2482 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2483 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2484
2485second_end:
2486 volatile store i32 0, i32* @g ; This time, the instruction always depends
2487 ; on the store in %end. Also, it is
2488 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2489 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2490 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2491</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2492
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2493</div>
2494
2495<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2496<h3>
2497 <a name="blockaddress">Addresses of Basic Blocks</a>
2498</h3>
2499
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2500<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2501
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2502<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2503
2504<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2505 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2506 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2507
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2508<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2509 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2510 comparisons against null. Pointer equality tests between labels addresses
2511 results in undefined behavior &mdash; though, again, comparison against null
2512 is ok, and no label is equal to the null pointer. This may be passed around
2513 as an opaque pointer sized value as long as the bits are not inspected. This
2514 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2515 long as the original value is reconstituted before the <tt>indirectbr</tt>
2516 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2517
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2518<p>Finally, some targets may provide defined semantics when using the value as
2519 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2520
2521</div>
2522
2523
2524<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2525<h3>
2526 <a name="constantexprs">Constant Expressions</a>
2527</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2528
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2529<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2530
2531<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2532 to be used as constants. Constant expressions may be of
2533 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2534 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2535 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2536
2537<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2538 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2539 <dd>Truncate a constant to another type. The bit size of CST must be larger
2540 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2541
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2542 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2543 <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]2544 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2545
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2546 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2547 <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]2548 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2549
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2550 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2551 <dd>Truncate a floating point constant to another floating point type. The
2552 size of CST must be larger than the size of TYPE. Both types must be
2553 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2554
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2555 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2556 <dd>Floating point extend a constant to another type. The size of CST must be
2557 smaller or equal to the size of TYPE. Both types must be floating
2558 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2559
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2560 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2561 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2562 constant. TYPE must be a scalar or vector integer type. CST must be of
2563 scalar or vector floating point type. Both CST and TYPE must be scalars,
2564 or vectors of the same number of elements. If the value won't fit in the
2565 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2566
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2567 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2568 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2569 constant. TYPE must be a scalar or vector integer type. CST must be of
2570 scalar or vector floating point type. Both CST and TYPE must be scalars,
2571 or vectors of the same number of elements. If the value won't fit in the
2572 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2573
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2574 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2575 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2576 constant. TYPE must be a scalar or vector floating point type. CST must be
2577 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2578 vectors of the same number of elements. If the value won't fit in the
2579 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2580
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2581 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2582 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2583 constant. TYPE must be a scalar or vector floating point type. CST must be
2584 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2585 vectors of the same number of elements. If the value won't fit in the
2586 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2587
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2588 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2589 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2590 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2591 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2592 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2593
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2594 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2595 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2596 type. CST must be of integer type. The CST value is zero extended,
2597 truncated, or unchanged to make it fit in a pointer size. This one is
2598 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2599
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2600 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2601 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2602 are the same as those for the <a href="#i_bitcast">bitcast
2603 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2604
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2605 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2606 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2607 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2608 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2609 instruction, the index list may have zero or more indexes, which are
2610 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2611
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2612 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2613 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2614
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2615 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2616 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2617
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2618 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2619 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2620
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2621 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2622 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2623 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2624
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2625 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2626 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2627 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2628
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2629 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2630 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2631 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2632
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2633 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2634 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2635 constants. The index list is interpreted in a similar manner as indices in
2636 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2637 index value must be specified.</dd>
2638
2639 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2640 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2641 constants. The index list is interpreted in a similar manner as indices in
2642 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2643 index value must be specified.</dd>
2644
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2645 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2646 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2647 be any of the <a href="#binaryops">binary</a>
2648 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2649 on operands are the same as those for the corresponding instruction
2650 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2651</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2652
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2653</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2654
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2655</div>
2656
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2657<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2658<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2659<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2660<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2661<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2662<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2663<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2664</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2665
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2666<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2667
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2668<p>LLVM supports inline assembler expressions (as opposed
2669 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2670 a special value. This value represents the inline assembler as a string
2671 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2672 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2673 expression has side effects, and a flag indicating whether the function
2674 containing the asm needs to align its stack conservatively. An example
2675 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2676
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2677<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2678i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2679</pre>
2680
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2681<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2682 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2683 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2684
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2685<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2686%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]2687</pre>
2688
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2689<p>Inline asms with side effects not visible in the constraint list must be
2690 marked as having side effects. This is done through the use of the
2691 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2692
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2693<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2694call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2695</pre>
2696
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2697<p>In some cases inline asms will contain code that will not work unless the
2698 stack is aligned in some way, such as calls or SSE instructions on x86,
2699 yet will not contain code that does that alignment within the asm.
2700 The compiler should make conservative assumptions about what the asm might
2701 contain and should generate its usual stack alignment code in the prologue
2702 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2703
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2704<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2705call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2706</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2707
2708<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2709 first.</p>
2710
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2711<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2712 documented here. Constraints on what can be done (e.g. duplication, moving,
2713 etc need to be documented). This is probably best done by reference to
2714 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2715
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2716<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2717<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2718</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2719
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2720<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2721
2722<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2723 attached to it that contains a list of constant integers. If present, the
2724 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2725 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2726 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2727 source code that produced it. For example:</p>
2728
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2729<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2730call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2731...
2732!42 = !{ i32 1234567 }
2733</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2734
2735<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2736 IR. If the MDNode contains multiple constants, the code generator will use
2737 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]2738
2739</div>
2740
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2741</div>
2742
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2743<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2744<h3>
2745 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2746</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2747
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2748<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2749
2750<p>LLVM IR allows metadata to be attached to instructions in the program that
2751 can convey extra information about the code to the optimizers and code
2752 generator. One example application of metadata is source-level debug
2753 information. There are two metadata primitives: strings and nodes. All
2754 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2755 preceding exclamation point ('<tt>!</tt>').</p>
2756
2757<p>A metadata string is a string surrounded by double quotes. It can contain
2758 any character by escaping non-printable characters with "\xx" where "xx" is
2759 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2760
2761<p>Metadata nodes are represented with notation similar to structure constants
2762 (a comma separated list of elements, surrounded by braces and preceded by an
2763 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2764 10}</tt>". Metadata nodes can have any values as their operand.</p>
2765
2766<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2767 metadata nodes, which can be looked up in the module symbol table. For
2768 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2769
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2770<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2771 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2772
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2773<div class="doc_code">
2774<pre>
2775call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2776</pre>
2777</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2778
2779<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2780 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2781
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2782<div class="doc_code">
2783<pre>
2784%indvar.next = add i64 %indvar, 1, !dbg !21
2785</pre>
2786</div>
2787
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2788</div>
2789
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2790</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2791
2792<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2793<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2794 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2795</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2796<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2797<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2798<p>LLVM has a number of "magic" global variables that contain data that affect
2799code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2800of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2801section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2802by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2803
2804<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2805<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2806<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2807</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2808
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2809<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2810
2811<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2812href="#linkage_appending">appending linkage</a>. This array contains a list of
2813pointers to global variables and functions which may optionally have a pointer
2814cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2815
2816<pre>
2817 @X = global i8 4
2818 @Y = global i32 123
2819
2820 @llvm.used = appending global [2 x i8*] [
2821 i8* @X,
2822 i8* bitcast (i32* @Y to i8*)
2823 ], section "llvm.metadata"
2824</pre>
2825
2826<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2827compiler, assembler, and linker are required to treat the symbol as if there is
2828a reference to the global that it cannot see. For example, if a variable has
2829internal linkage and no references other than that from the <tt>@llvm.used</tt>
2830list, it cannot be deleted. This is commonly used to represent references from
2831inline asms and other things the compiler cannot "see", and corresponds to
2832"attribute((used))" in GNU C.</p>
2833
2834<p>On some targets, the code generator must emit a directive to the assembler or
2835object file to prevent the assembler and linker from molesting the symbol.</p>
2836
2837</div>
2838
2839<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2840<h3>
2841 <a name="intg_compiler_used">
2842 The '<tt>llvm.compiler.used</tt>' Global Variable
2843 </a>
2844</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2845
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2846<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2847
2848<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2849<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2850touching the symbol. On targets that support it, this allows an intelligent
2851linker to optimize references to the symbol without being impeded as it would be
2852by <tt>@llvm.used</tt>.</p>
2853
2854<p>This is a rare construct that should only be used in rare circumstances, and
2855should not be exposed to source languages.</p>
2856
2857</div>
2858
2859<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2860<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2861<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2862</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2863
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2864<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2865<pre>
2866%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2867@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2868</pre>
2869<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2870</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2871
2872</div>
2873
2874<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2875<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2876<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2877</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2878
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2879<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2880<pre>
2881%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2882@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2883</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2884
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2885<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2886</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2887
2888</div>
2889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2890</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2891
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2892<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2893<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2894<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2895
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2896<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2897
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2898<p>The LLVM instruction set consists of several different classifications of
2899 instructions: <a href="#terminators">terminator
2900 instructions</a>, <a href="#binaryops">binary instructions</a>,
2901 <a href="#bitwiseops">bitwise binary instructions</a>,
2902 <a href="#memoryops">memory instructions</a>, and
2903 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2904
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2905<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2906<h3>
2907 <a name="terminators">Terminator Instructions</a>
2908</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2909
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2910<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2911
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2912<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2913 in a program ends with a "Terminator" instruction, which indicates which
2914 block should be executed after the current block is finished. These
2915 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2916 control flow, not values (the one exception being the
2917 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2918
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2919<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2920 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2921 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2922 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2923 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2924 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2925 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2926 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2927
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2928<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2929<h4>
2930 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2931</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2932
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2933<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2934
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2935<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2936<pre>
2937 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]2938 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2939</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2940
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2941<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2942<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2943 a value) from a function back to the caller.</p>
2944
2945<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2946 value and then causes control flow, and one that just causes control flow to
2947 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2948
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2949<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2950<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2951 return value. The type of the return value must be a
2952 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2953
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2954<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2955 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2956 value or a return value with a type that does not match its type, or if it
2957 has a void return type and contains a '<tt>ret</tt>' instruction with a
2958 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2959
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2960<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2961<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2962 the calling function's context. If the caller is a
2963 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2964 instruction after the call. If the caller was an
2965 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2966 the beginning of the "normal" destination block. If the instruction returns
2967 a value, that value shall set the call or invoke instruction's return
2968 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2969
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2970<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2971<pre>
2972 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2973 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2974 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]2975</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2976
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2977</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2978<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2979<h4>
2980 <a name="i_br">'<tt>br</tt>' Instruction</a>
2981</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2982
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2983<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2984
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2985<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2986<pre>
2987 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2988</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2989
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2990<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2991<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2992 different basic block in the current function. There are two forms of this
2993 instruction, corresponding to a conditional branch and an unconditional
2994 branch.</p>
2995
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2996<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2997<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2998 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2999 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3000 target.</p>
3001
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3002<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3003<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3004 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3005 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3006 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3007
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3008<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3009<pre>
3010Test:
3011 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3012 br i1 %cond, label %IfEqual, label %IfUnequal
3013IfEqual:
3014 <a href="#i_ret">ret</a> i32 1
3015IfUnequal:
3016 <a href="#i_ret">ret</a> i32 0
3017</pre>
3018
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3019</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3021<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3022<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3023 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3024</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3025
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3026<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3027
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3028<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3029<pre>
3030 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3031</pre>
3032
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3033<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3034<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]3035 several different places. It is a generalization of the '<tt>br</tt>'
3036 instruction, allowing a branch to occur to one of many possible
3037 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3038
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3039<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3040<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3041 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3042 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3043 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3044
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3045<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3046<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3047 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3048 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3049 transferred to the corresponding destination; otherwise, control flow is
3050 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3051
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3052<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3053<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3054 <tt>switch</tt> instruction, this instruction may be code generated in
3055 different ways. For example, it could be generated as a series of chained
3056 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3057
3058<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3059<pre>
3060 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3061 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3062 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3063
3064 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3065 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3066
3067 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3068 switch i32 %val, label %otherwise [ i32 0, label %onzero
3069 i32 1, label %onone
3070 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3071</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3072
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3073</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3074
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3075
3076<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3077<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3078 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3079</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3080
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3081<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3082
3083<h5>Syntax:</h5>
3084<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3085 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]3086</pre>
3087
3088<h5>Overview:</h5>
3089
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3090<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3091 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3092 "<tt>address</tt>". Address must be derived from a <a
3093 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3094
3095<h5>Arguments:</h5>
3096
3097<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3098 rest of the arguments indicate the full set of possible destinations that the
3099 address may point to. Blocks are allowed to occur multiple times in the
3100 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3101
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3102<p>This destination list is required so that dataflow analysis has an accurate
3103 understanding of the CFG.</p>
3104
3105<h5>Semantics:</h5>
3106
3107<p>Control transfers to the block specified in the address argument. All
3108 possible destination blocks must be listed in the label list, otherwise this
3109 instruction has undefined behavior. This implies that jumps to labels
3110 defined in other functions have undefined behavior as well.</p>
3111
3112<h5>Implementation:</h5>
3113
3114<p>This is typically implemented with a jump through a register.</p>
3115
3116<h5>Example:</h5>
3117<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3118 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3119</pre>
3120
3121</div>
3122
3123
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3124<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3125<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3126 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3127</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3128
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3129<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3130
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3131<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3132<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3133 &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]3134 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3135</pre>
3136
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3137<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3138<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3139 function, with the possibility of control flow transfer to either the
3140 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3141 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3142 control flow will return to the "normal" label. If the callee (or any
3143 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3144 instruction, control is interrupted and continued at the dynamically nearest
3145 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3146
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3147<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3148<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3149
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3150<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3151 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3152 convention</a> the call should use. If none is specified, the call
3153 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3154
3155 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3156 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3157 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3158
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3159 <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]3160 function value being invoked. In most cases, this is a direct function
3161 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3162 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3163
3164 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3165 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3166
3167 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3168 signature argument types and parameter attributes. All arguments must be
3169 of <a href="#t_firstclass">first class</a> type. If the function
3170 signature indicates the function accepts a variable number of arguments,
3171 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3172
3173 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3174 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3175
3176 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3177 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3178
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3179 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3180 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3181 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3182</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3183
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3184<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3185<p>This instruction is designed to operate as a standard
3186 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3187 primary difference is that it establishes an association with a label, which
3188 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3189
3190<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3191 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3192 exception. Additionally, this is important for implementation of
3193 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3194
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3195<p>For the purposes of the SSA form, the definition of the value returned by the
3196 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3197 block to the "normal" label. If the callee unwinds then no return value is
3198 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3199
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3200<p>Note that the code generator does not yet completely support unwind, and
3201that the invoke/unwind semantics are likely to change in future versions.</p>
3202
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3203<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3204<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3205 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3206 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3207 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3208 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3209</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3210
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3211</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3212
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3213<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3214
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3215<h4>
3216 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3217</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3218
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3219<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3220
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3221<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3222<pre>
3223 unwind
3224</pre>
3225
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3226<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3227<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3228 at the first callee in the dynamic call stack which used
3229 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3230 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3231
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3232<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3233<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3234 immediately halt. The dynamic call stack is then searched for the
3235 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3236 Once found, execution continues at the "exceptional" destination block
3237 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3238 instruction in the dynamic call chain, undefined behavior results.</p>
3239
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3240<p>Note that the code generator does not yet completely support unwind, and
3241that the invoke/unwind semantics are likely to change in future versions.</p>
3242
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3243</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3244
3245<!-- _______________________________________________________________________ -->
3246
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3247<h4>
3248 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3249</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3250
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3251<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3252
3253<h5>Syntax:</h5>
3254<pre>
3255 unreachable
3256</pre>
3257
3258<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3259<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3260 instruction is used to inform the optimizer that a particular portion of the
3261 code is not reachable. This can be used to indicate that the code after a
3262 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3263
3264<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3265<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3266
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3267</div>
3268
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3269</div>
3270
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3271<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3272<h3>
3273 <a name="binaryops">Binary Operations</a>
3274</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3275
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3276<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3277
3278<p>Binary operators are used to do most of the computation in a program. They
3279 require two operands of the same type, execute an operation on them, and
3280 produce a single value. The operands might represent multiple data, as is
3281 the case with the <a href="#t_vector">vector</a> data type. The result value
3282 has the same type as its operands.</p>
3283
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3284<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3285
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3286<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3287<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3288 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3289</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3290
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3291<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3292
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3293<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3294<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3295 &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]3296 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3297 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3298 &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]3299</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3301<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3302<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3303
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3304<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3305<p>The two arguments to the '<tt>add</tt>' instruction must
3306 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3307 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3308
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3309<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3310<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3311
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3312<p>If the sum has unsigned overflow, the result returned is the mathematical
3313 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]3314
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3315<p>Because LLVM integers use a two's complement representation, this instruction
3316 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3317
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3318<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3319 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3320 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3321 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3322 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3324<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3325<pre>
3326 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3327</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3328
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3329</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3330
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3331<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3332<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3333 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3334</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3335
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3336<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3337
3338<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3339<pre>
3340 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3341</pre>
3342
3343<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3344<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3345
3346<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3347<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3348 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3349 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3350
3351<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3352<p>The value produced is the floating point sum of the two operands.</p>
3353
3354<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3355<pre>
3356 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3357</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3358
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3359</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3360
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3361<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3362<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3363 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3364</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3365
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3366<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3367
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3368<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3369<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3370 &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]3371 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3372 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3373 &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]3374</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3377<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3378 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3379
3380<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3381 '<tt>neg</tt>' instruction present in most other intermediate
3382 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385<p>The two arguments to the '<tt>sub</tt>' instruction must
3386 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3387 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3389<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3390<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3391
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3392<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3393 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3394 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3395
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3396<p>Because LLVM integers use a two's complement representation, this instruction
3397 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3398
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3399<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3400 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3401 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3402 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3403 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3404
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3405<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3406<pre>
3407 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3408 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3409</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3410
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3411</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3412
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3413<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3414<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3415 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3416</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3417
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3418<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3419
3420<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3421<pre>
3422 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3423</pre>
3424
3425<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3426<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3427 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3428
3429<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3430 '<tt>fneg</tt>' instruction present in most other intermediate
3431 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3432
3433<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3434<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3435 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3436 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3437
3438<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3439<p>The value produced is the floating point difference of the two operands.</p>
3440
3441<h5>Example:</h5>
3442<pre>
3443 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3444 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3445</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3446
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3447</div>
3448
3449<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3450<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3451 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3452</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3453
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3454<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3455
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3456<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3457<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3458 &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]3459 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3460 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3461 &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]3462</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3464<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3465<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3466
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3467<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3468<p>The two arguments to the '<tt>mul</tt>' instruction must
3469 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3470 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3472<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3473<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3474
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3475<p>If the result of the multiplication has unsigned overflow, the result
3476 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3477 width of the result.</p>
3478
3479<p>Because LLVM integers use a two's complement representation, and the result
3480 is the same width as the operands, this instruction returns the correct
3481 result for both signed and unsigned integers. If a full product
3482 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3483 be sign-extended or zero-extended as appropriate to the width of the full
3484 product.</p>
3485
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3486<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3487 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3488 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3489 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3490 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3491
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3492<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3493<pre>
3494 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3495</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3496
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3497</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3498
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3499<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3500<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3501 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3502</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3503
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3504<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3505
3506<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3507<pre>
3508 &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]3509</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3510
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3511<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3512<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3513
3514<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3515<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3516 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3517 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3518
3519<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3520<p>The value produced is the floating point product of the two operands.</p>
3521
3522<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3523<pre>
3524 &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]3525</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3526
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3527</div>
3528
3529<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3530<h4>
3531 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3532</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3533
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3534<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3535
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3536<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3537<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3538 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3539 &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]3540</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3541
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3542<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3543<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3544
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3545<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3546<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3547 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3548 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3549
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3550<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3551<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3552
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3553<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3554 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3555
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3556<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3557
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3558<p>If the <tt>exact</tt> keyword is present, the result value of the
3559 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3560 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3561
3562
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3563<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3564<pre>
3565 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3566</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3567
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3568</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3569
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3570<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3571<h4>
3572 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3573</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3574
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3575<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3576
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3577<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3578<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3579 &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]3580 &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]3581</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3582
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3583<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3584<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3585
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3586<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3587<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3588 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3589 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3590
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3591<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3592<p>The value produced is the signed integer quotient of the two operands rounded
3593 towards zero.</p>
3594
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3595<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3596 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3597
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3598<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3599 undefined behavior; this is a rare case, but can occur, for example, by doing
3600 a 32-bit division of -2147483648 by -1.</p>
3601
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3602<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3603 <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]3604 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3605
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3606<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3607<pre>
3608 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3609</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3611</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3612
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3613<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3614<h4>
3615 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3616</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3617
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3618<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3619
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3620<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3621<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3622 &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]3623</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3624
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3625<h5>Overview:</h5>
3626<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3627
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3628<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3629<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3630 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3631 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3632
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3633<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3634<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3635
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3636<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3637<pre>
3638 &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]3639</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3640
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3641</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3642
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3643<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3644<h4>
3645 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3646</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3647
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3648<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3649
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3650<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651<pre>
3652 &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]3653</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3654
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3655<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3656<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3657 division of its two arguments.</p>
3658
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3659<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3660<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3661 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3662 values. Both arguments must have identical types.</p>
3663
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3664<h5>Semantics:</h5>
3665<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3666 This instruction always performs an unsigned division to get the
3667 remainder.</p>
3668
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3669<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3670 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3671
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3672<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3674<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3675<pre>
3676 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3677</pre>
3678
3679</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3681<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3682<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3683 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3684</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3685
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3686<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3687
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3688<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3689<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3690 &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]3691</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3692
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3693<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3694<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3695 division of its two operands. This instruction can also take
3696 <a href="#t_vector">vector</a> versions of the values in which case the
3697 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3698
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3699<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3700<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3701 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3702 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3703
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3704<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3705<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3706 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3707 <i>modulo</i> operator (where the result is either zero or has the same sign
3708 as the divisor, <tt>op2</tt>) of a value.
3709 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3710 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3711 Math Forum</a>. For a table of how this is implemented in various languages,
3712 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3713 Wikipedia: modulo operation</a>.</p>
3714
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3715<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3716 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3717
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3718<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3719 Overflow also leads to undefined behavior; this is a rare case, but can
3720 occur, for example, by taking the remainder of a 32-bit division of
3721 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3722 lets srem be implemented using instructions that return both the result of
3723 the division and the remainder.)</p>
3724
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3725<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3726<pre>
3727 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3728</pre>
3729
3730</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3731
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3732<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3733<h4>
3734 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3735</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3736
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3737<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3738
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3739<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3740<pre>
3741 &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]3742</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3743
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3744<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3745<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3746 its two operands.</p>
3747
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3748<h5>Arguments:</h5>
3749<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3750 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3751 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3752
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3753<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3754<p>This instruction returns the <i>remainder</i> of a division. The remainder
3755 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3756
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3757<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3758<pre>
3759 &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]3760</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3761
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3762</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3763
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3764</div>
3765
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3766<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3767<h3>
3768 <a name="bitwiseops">Bitwise Binary Operations</a>
3769</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3771<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3772
3773<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3774 program. They are generally very efficient instructions and can commonly be
3775 strength reduced from other instructions. They require two operands of the
3776 same type, execute an operation on them, and produce a single value. The
3777 resulting value is the same type as its operands.</p>
3778
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3779<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3780<h4>
3781 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3782</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3783
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3784<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3785
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3786<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3787<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3788 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3789 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3790 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3791 &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]3792</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3793
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3794<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3795<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3796 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3797
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3798<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3799<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3800 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3801 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3802
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3803<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3804<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3805 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3806 is (statically or dynamically) negative or equal to or larger than the number
3807 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3808 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3809 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3810
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3811<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3812 <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]3813 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3814 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3815 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3816 they would if the shift were expressed as a mul instruction with the same
3817 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3818
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3819<h5>Example:</h5>
3820<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3821 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3822 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3823 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3824 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3825 &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]3826</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3827
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3828</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3829
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3830<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3831<h4>
3832 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3833</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3834
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3835<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3836
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3837<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3838<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3839 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3840 &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]3841</pre>
3842
3843<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3844<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3845 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3846
3847<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3848<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3849 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3850 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3851
3852<h5>Semantics:</h5>
3853<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3854 significant bits of the result will be filled with zero bits after the shift.
3855 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3856 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3857 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3858 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3859
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3860<p>If the <tt>exact</tt> keyword is present, the result value of the
3861 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3862 shifted out are non-zero.</p>
3863
3864
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3865<h5>Example:</h5>
3866<pre>
3867 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3868 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3869 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3870 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3871 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3872 &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]3873</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3874
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3875</div>
3876
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3877<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3878<h4>
3879 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3880</h4>
3881
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3882<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3883
3884<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3885<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3886 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3887 &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]3888</pre>
3889
3890<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3891<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3892 operand shifted to the right a specified number of bits with sign
3893 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3894
3895<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3896<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3897 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3898 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3899
3900<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3901<p>This instruction always performs an arithmetic shift right operation, The
3902 most significant bits of the result will be filled with the sign bit
3903 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3904 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3905 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3906 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3907
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3908<p>If the <tt>exact</tt> keyword is present, the result value of the
3909 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3910 shifted out are non-zero.</p>
3911
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3912<h5>Example:</h5>
3913<pre>
3914 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3915 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3916 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3917 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3918 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3919 &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]3920</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3921
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3922</div>
3923
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3924<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3925<h4>
3926 <a name="i_and">'<tt>and</tt>' Instruction</a>
3927</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3928
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3929<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3930
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3931<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3932<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3933 &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]3934</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3935
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3936<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3937<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3938 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3939
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3940<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3941<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3942 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3943 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3944
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3945<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3946<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3947
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3948<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3949 <tbody>
3950 <tr>
3951 <td>In0</td>
3952 <td>In1</td>
3953 <td>Out</td>
3954 </tr>
3955 <tr>
3956 <td>0</td>
3957 <td>0</td>
3958 <td>0</td>
3959 </tr>
3960 <tr>
3961 <td>0</td>
3962 <td>1</td>
3963 <td>0</td>
3964 </tr>
3965 <tr>
3966 <td>1</td>
3967 <td>0</td>
3968 <td>0</td>
3969 </tr>
3970 <tr>
3971 <td>1</td>
3972 <td>1</td>
3973 <td>1</td>
3974 </tr>
3975 </tbody>
3976</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3977
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3978<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3979<pre>
3980 &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]3981 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3982 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3983</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3984</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3985<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3986<h4>
3987 <a name="i_or">'<tt>or</tt>' Instruction</a>
3988</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3989
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3990<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3991
3992<h5>Syntax:</h5>
3993<pre>
3994 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3995</pre>
3996
3997<h5>Overview:</h5>
3998<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3999 two operands.</p>
4000
4001<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4002<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4003 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4004 values. Both arguments must have identical types.</p>
4005
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4006<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4007<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4008
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4009<table border="1" cellspacing="0" cellpadding="4">
4010 <tbody>
4011 <tr>
4012 <td>In0</td>
4013 <td>In1</td>
4014 <td>Out</td>
4015 </tr>
4016 <tr>
4017 <td>0</td>
4018 <td>0</td>
4019 <td>0</td>
4020 </tr>
4021 <tr>
4022 <td>0</td>
4023 <td>1</td>
4024 <td>1</td>
4025 </tr>
4026 <tr>
4027 <td>1</td>
4028 <td>0</td>
4029 <td>1</td>
4030 </tr>
4031 <tr>
4032 <td>1</td>
4033 <td>1</td>
4034 <td>1</td>
4035 </tr>
4036 </tbody>
4037</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4038
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4039<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4040<pre>
4041 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4042 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4043 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4044</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4046</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4048<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4049<h4>
4050 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4051</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4052
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4053<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4054
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4055<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4056<pre>
4057 &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]4058</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4059
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4060<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4061<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4062 its two operands. The <tt>xor</tt> is used to implement the "one's
4063 complement" operation, which is the "~" operator in C.</p>
4064
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4065<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4066<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4067 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4068 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4069
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4070<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4071<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4072
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4073<table border="1" cellspacing="0" cellpadding="4">
4074 <tbody>
4075 <tr>
4076 <td>In0</td>
4077 <td>In1</td>
4078 <td>Out</td>
4079 </tr>
4080 <tr>
4081 <td>0</td>
4082 <td>0</td>
4083 <td>0</td>
4084 </tr>
4085 <tr>
4086 <td>0</td>
4087 <td>1</td>
4088 <td>1</td>
4089 </tr>
4090 <tr>
4091 <td>1</td>
4092 <td>0</td>
4093 <td>1</td>
4094 </tr>
4095 <tr>
4096 <td>1</td>
4097 <td>1</td>
4098 <td>0</td>
4099 </tr>
4100 </tbody>
4101</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4102
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4103<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4104<pre>
4105 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4106 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4107 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4108 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4109</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4110
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4111</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4112
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4113</div>
4114
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4115<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4116<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4117 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4118</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4119
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4120<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4121
4122<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4123 target-independent manner. These instructions cover the element-access and
4124 vector-specific operations needed to process vectors effectively. While LLVM
4125 does directly support these vector operations, many sophisticated algorithms
4126 will want to use target-specific intrinsics to take full advantage of a
4127 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4128
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4129<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4130<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4131 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4132</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4133
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4134<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4135
4136<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4137<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4138 &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]4139</pre>
4140
4141<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4142<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4143 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4144
4145
4146<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4148 of <a href="#t_vector">vector</a> type. The second operand is an index
4149 indicating the position from which to extract the element. The index may be
4150 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4151
4152<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4153<p>The result is a scalar of the same type as the element type of
4154 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4155 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4156 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4157
4158<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4159<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4160 &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]4161</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4162
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4163</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4164
4165<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4166<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4167 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4168</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4169
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4170<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4171
4172<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4173<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4174 &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]4175</pre>
4176
4177<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4178<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4179 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4180
4181<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4182<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4183 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4184 whose type must equal the element type of the first operand. The third
4185 operand is an index indicating the position at which to insert the value.
4186 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4187
4188<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4189<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4190 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4191 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4192 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4193
4194<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4195<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4196 &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]4197</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4198
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4199</div>
4200
4201<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4202<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4203 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4204</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4205
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4206<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4207
4208<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4209<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4210 &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]4211</pre>
4212
4213<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4214<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4215 from two input vectors, returning a vector with the same element type as the
4216 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4217
4218<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4219<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4220 with types that match each other. The third argument is a shuffle mask whose
4221 element type is always 'i32'. The result of the instruction is a vector
4222 whose length is the same as the shuffle mask and whose element type is the
4223 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4224
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4225<p>The shuffle mask operand is required to be a constant vector with either
4226 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4227
4228<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4229<p>The elements of the two input vectors are numbered from left to right across
4230 both of the vectors. The shuffle mask operand specifies, for each element of
4231 the result vector, which element of the two input vectors the result element
4232 gets. The element selector may be undef (meaning "don't care") and the
4233 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4234
4235<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4236<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4237 &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]4238 &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]4239 &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]4240 &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]4241 &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]4242 &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]4243 &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]4244 &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]4245</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4246
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4247</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4248
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4249</div>
4250
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4251<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4252<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4253 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4254</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4255
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4256<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4257
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4258<p>LLVM supports several instructions for working with
4259 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4260
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4261<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4262<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4263 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4264</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4265
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4266<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4267
4268<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4269<pre>
4270 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4271</pre>
4272
4273<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4274<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4275 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4276
4277<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4278<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4279 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4280 <a href="#t_array">array</a> type. The operands are constant indices to
4281 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4282 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4283 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4284 <ul>
4285 <li>Since the value being indexed is not a pointer, the first index is
4286 omitted and assumed to be zero.</li>
4287 <li>At least one index must be specified.</li>
4288 <li>Not only struct indices but also array indices must be in
4289 bounds.</li>
4290 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4291
4292<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4293<p>The result is the value at the position in the aggregate specified by the
4294 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4295
4296<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4297<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4298 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4299</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4300
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4301</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4302
4303<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4304<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4305 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4306</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4307
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4308<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4309
4310<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4311<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4312 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4313</pre>
4314
4315<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4316<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4317 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4318
4319<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4320<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4321 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4322 <a href="#t_array">array</a> type. The second operand is a first-class
4323 value to insert. The following operands are constant indices indicating
4324 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]4325 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4326 value to insert must have the same type as the value identified by the
4327 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4328
4329<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4330<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4331 that of <tt>val</tt> except that the value at the position specified by the
4332 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4333
4334<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4335<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4336 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4337 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4338 %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]4339</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4340
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4341</div>
4342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4343</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4344
4345<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4346<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4347 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4348</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4349
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4350<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4351
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4352<p>A key design point of an SSA-based representation is how it represents
4353 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4354 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4357<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4358<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4359 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4360</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4361
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4362<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4364<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4365<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4366 &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]4367</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4368
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4369<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4370<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4371 currently executing function, to be automatically released when this function
4372 returns to its caller. The object is always allocated in the generic address
4373 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4374
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4375<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4376<p>The '<tt>alloca</tt>' instruction
4377 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4378 runtime stack, returning a pointer of the appropriate type to the program.
4379 If "NumElements" is specified, it is the number of elements allocated,
4380 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4381 specified, the value result of the allocation is guaranteed to be aligned to
4382 at least that boundary. If not specified, or if zero, the target can choose
4383 to align the allocation on any convenient boundary compatible with the
4384 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4385
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4386<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4388<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4389<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4390 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4391 memory is automatically released when the function returns. The
4392 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4393 variables that must have an address available. When the function returns
4394 (either with the <tt><a href="#i_ret">ret</a></tt>
4395 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4396 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4398<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4399<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4400 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4401 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4402 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4403 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</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
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4408<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4409<h4>
4410 <a name="i_load">'<tt>load</tt>' Instruction</a>
4411</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4412
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4413<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4414
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4415<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4416<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4417 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4418 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4419 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4420</pre>
4421
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4422<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4423<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4424
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4425<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4426<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4427 from which to load. The pointer must point to
4428 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4429 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4430 number or order of execution of this <tt>load</tt> with other <a
4431 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4432
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4433<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4434 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]4435 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4436 alignment for the target. It is the responsibility of the code emitter to
4437 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4438 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4439 produce less efficient code. An alignment of 1 is always safe.</p>
4440
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4441<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4442 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4443 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4444 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4445 and code generator that this load is not expected to be reused in the cache.
4446 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4447 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4448
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4449<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4450<p>The location of memory pointed to is loaded. If the value being loaded is of
4451 scalar type then the number of bytes read does not exceed the minimum number
4452 of bytes needed to hold all bits of the type. For example, loading an
4453 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4454 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4455 is undefined if the value was not originally written using a store of the
4456 same type.</p>
4457
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4458<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4459<pre>
4460 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4461 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4462 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4463</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4464
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4465</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4466
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4467<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4468<h4>
4469 <a name="i_store">'<tt>store</tt>' Instruction</a>
4470</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4471
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4472<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4473
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4474<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4475<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4476 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4477 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4478</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4479
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4480<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4481<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4482
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4483<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4484<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4485 and an address at which to store it. The type of the
4486 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4487 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4488 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4489 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4490 order of execution of this <tt>store</tt> with other <a
4491 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4492
4493<p>The optional constant "align" argument specifies the alignment of the
4494 operation (that is, the alignment of the memory address). A value of 0 or an
4495 omitted "align" argument means that the operation has the preferential
4496 alignment for the target. It is the responsibility of the code emitter to
4497 ensure that the alignment information is correct. Overestimating the
4498 alignment results in an undefined behavior. Underestimating the alignment may
4499 produce less efficient code. An alignment of 1 is always safe.</p>
4500
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4501<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4502 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4503 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4504 instruction tells the optimizer and code generator that this load is
4505 not expected to be reused in the cache. The code generator may
4506 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4507 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4508
4509
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4510<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4511<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4512 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4513 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4514 does not exceed the minimum number of bytes needed to hold all bits of the
4515 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4516 writing a value of a type like <tt>i20</tt> with a size that is not an
4517 integral number of bytes, it is unspecified what happens to the extra bits
4518 that do not belong to the type, but they will typically be overwritten.</p>
4519
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4520<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4521<pre>
4522 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4523 store i32 3, i32* %ptr <i>; yields {void}</i>
4524 %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]4525</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4526
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4527</div>
4528
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4529<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4530<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4531 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4532</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4533
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4534<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4535
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4536<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4537<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4538 &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]4539 &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]4540</pre>
4541
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4542<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4543<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4544 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4545 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4546
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4547<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4548<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4549 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4550 elements of the aggregate object are indexed. The interpretation of each
4551 index is dependent on the type being indexed into. The first index always
4552 indexes the pointer value given as the first argument, the second index
4553 indexes a value of the type pointed to (not necessarily the value directly
4554 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4555 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4556 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4557 can never be pointers, since that would require loading the pointer before
4558 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4559
4560<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]4561 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4562 integer <b>constants</b> are allowed. When indexing into an array, pointer
4563 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4564 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4565
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4566<p>For example, let's consider a C code fragment and how it gets compiled to
4567 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4568
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4569<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4570struct RT {
4571 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4572 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4573 char C;
4574};
4575struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4576 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4577 double Y;
4578 struct RT Z;
4579};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4580
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4581int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4582 return &amp;s[1].Z.B[5][13];
4583}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4584</pre>
4585
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4586<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4587
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4588<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4589%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4590%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4591
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4592define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4593entry:
4594 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4595 ret i32* %reg
4596}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4597</pre>
4598
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4599<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4600<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]4601 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4602 }</tt>' type, a structure. The second index indexes into the third element
4603 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4604 i8 }</tt>' type, another structure. The third index indexes into the second
4605 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4606 array. The two dimensions of the array are subscripted into, yielding an
4607 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4608 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4609
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4610<p>Note that it is perfectly legal to index partially through a structure,
4611 returning a pointer to an inner element. Because of this, the LLVM code for
4612 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4613
4614<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4615 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4616 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4617 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4618 %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]4619 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4620 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4621 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4622 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4623</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4624
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4625<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4626 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4627 base pointer is not an <i>in bounds</i> address of an allocated object,
4628 or if any of the addresses that would be formed by successive addition of
4629 the offsets implied by the indices to the base address with infinitely
4630 precise arithmetic are not an <i>in bounds</i> address of that allocated
4631 object. The <i>in bounds</i> addresses for an allocated object are all
4632 the addresses that point into the object, plus the address one byte past
4633 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4634
4635<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4636 the base address with silently-wrapping two's complement arithmetic, and
4637 the result value of the <tt>getelementptr</tt> may be outside the object
4638 pointed to by the base pointer. The result value may not necessarily be
4639 used to access memory though, even if it happens to point into allocated
4640 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4641 section for more information.</p>
4642
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4643<p>The getelementptr instruction is often confusing. For some more insight into
4644 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4645
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4646<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4647<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4648 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4649 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4650 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4651 %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]4652 <i>; yields i8*:eptr</i>
4653 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4654 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4655 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4656</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4657
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4658</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4659
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4660</div>
4661
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4662<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4663<h3>
4664 <a name="convertops">Conversion Operations</a>
4665</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4666
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4667<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4668
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4669<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4670 which all take a single operand and a type. They perform various bit
4671 conversions on the operand.</p>
4672
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4673<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4674<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4675 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4676</h4>
4677
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4678<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4679
4680<h5>Syntax:</h5>
4681<pre>
4682 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4683</pre>
4684
4685<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4686<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4687 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4688
4689<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4690<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4691 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4692 of the same number of integers.
4693 The bit size of the <tt>value</tt> must be larger than
4694 the bit size of the destination type, <tt>ty2</tt>.
4695 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4696
4697<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4698<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4699 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4700 source size must be larger than the destination size, <tt>trunc</tt> cannot
4701 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4702
4703<h5>Example:</h5>
4704<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4705 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4706 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4707 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4708 %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]4709</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4710
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4711</div>
4712
4713<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4714<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4715 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4716</h4>
4717
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4718<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4719
4720<h5>Syntax:</h5>
4721<pre>
4722 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4723</pre>
4724
4725<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4726<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4727 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4728
4729
4730<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4731<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4732 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4733 of the same number of integers.
4734 The bit size of the <tt>value</tt> must be smaller than
4735 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4736 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4737
4738<h5>Semantics:</h5>
4739<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]4740 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4741
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4742<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]4743
4744<h5>Example:</h5>
4745<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4746 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4747 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4748 %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]4749</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4750
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4751</div>
4752
4753<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4754<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4755 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4756</h4>
4757
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4758<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4759
4760<h5>Syntax:</h5>
4761<pre>
4762 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4763</pre>
4764
4765<h5>Overview:</h5>
4766<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4767
4768<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4769<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4770 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4771 of the same number of integers.
4772 The bit size of the <tt>value</tt> must be smaller than
4773 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4774 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4775
4776<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4777<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4778 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4779 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4780
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4781<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]4782
4783<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4784<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4785 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4786 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4787 %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]4788</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4789
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4790</div>
4791
4792<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4793<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4794 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4795</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4796
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4797<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4798
4799<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4800<pre>
4801 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4802</pre>
4803
4804<h5>Overview:</h5>
4805<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4806 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4807
4808<h5>Arguments:</h5>
4809<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4810 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4811 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]4812 <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]4813 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4814
4815<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4816<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4817 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4818 <a href="#t_floating">floating point</a> type. If the value cannot fit
4819 within the destination type, <tt>ty2</tt>, then the results are
4820 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4821
4822<h5>Example:</h5>
4823<pre>
4824 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4825 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4826</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4827
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4828</div>
4829
4830<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4831<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4832 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4833</h4>
4834
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4835<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4836
4837<h5>Syntax:</h5>
4838<pre>
4839 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4840</pre>
4841
4842<h5>Overview:</h5>
4843<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]4844 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4845
4846<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4847<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4848 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4849 a <a href="#t_floating">floating point</a> type to cast it to. The source
4850 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4851
4852<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4853<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4854 <a href="#t_floating">floating point</a> type to a larger
4855 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4856 used to make a <i>no-op cast</i> because it always changes bits. Use
4857 <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]4858
4859<h5>Example:</h5>
4860<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]4861 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4862 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4863</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4864
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4865</div>
4866
4867<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4868<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4869 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4870</h4>
4871
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4872<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4873
4874<h5>Syntax:</h5>
4875<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4876 &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]4877</pre>
4878
4879<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4880<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4881 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4882
4883<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4884<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4885 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4886 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4887 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4888 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4889
4890<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4891<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4892 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4893 towards zero) unsigned integer value. If the value cannot fit
4894 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4895
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4896<h5>Example:</h5>
4897<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4898 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4899 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4900 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4901</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4902
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4903</div>
4904
4905<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4906<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4907 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4908</h4>
4909
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4910<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4911
4912<h5>Syntax:</h5>
4913<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4914 &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]4915</pre>
4916
4917<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4918<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4919 <a href="#t_floating">floating point</a> <tt>value</tt> to
4920 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4921
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4922<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4923<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4924 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4925 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4926 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4927 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4928
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4929<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4930<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4931 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4932 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4933 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4934
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4935<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4936<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4937 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4938 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4939 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4940</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4941
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4942</div>
4943
4944<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4945<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4946 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4947</h4>
4948
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4949<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4950
4951<h5>Syntax:</h5>
4952<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4953 &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]4954</pre>
4955
4956<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4957<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4958 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4959
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4960<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4961<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]4962 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4963 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4964 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4965 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4966
4967<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4968<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4969 integer quantity and converts it to the corresponding floating point
4970 value. If the value cannot fit in the floating point value, the results are
4971 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4972
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4973<h5>Example:</h5>
4974<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4975 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4976 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4977</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4978
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4979</div>
4980
4981<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4982<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4983 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4984</h4>
4985
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4986<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4987
4988<h5>Syntax:</h5>
4989<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4990 &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]4991</pre>
4992
4993<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4994<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4995 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4996
4997<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4998<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]4999 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5000 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5001 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5002 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5003
5004<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5005<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5006 quantity and converts it to the corresponding floating point value. If the
5007 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5008
5009<h5>Example:</h5>
5010<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5011 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5012 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5013</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5014
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5015</div>
5016
5017<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5018<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5019 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5020</h4>
5021
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5022<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5023
5024<h5>Syntax:</h5>
5025<pre>
5026 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5027</pre>
5028
5029<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5030<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5031 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5032
5033<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5034<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5035 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5036 <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]5037
5038<h5>Semantics:</h5>
5039<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5040 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5041 truncating or zero extending that value to the size of the integer type. If
5042 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5043 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5044 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5045 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5046
5047<h5>Example:</h5>
5048<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5049 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5050 %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]5051</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5052
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5053</div>
5054
5055<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5056<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5057 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5058</h4>
5059
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5060<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5061
5062<h5>Syntax:</h5>
5063<pre>
5064 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5065</pre>
5066
5067<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5068<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5069 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5070
5071<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5072<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5073 value to cast, and a type to cast it to, which must be a
5074 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5075
5076<h5>Semantics:</h5>
5077<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5078 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5079 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5080 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5081 than the size of a pointer then a zero extension is done. If they are the
5082 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5083
5084<h5>Example:</h5>
5085<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5086 %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]5087 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5088 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5089</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5090
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5091</div>
5092
5093<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5094<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5095 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5096</h4>
5097
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5098<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5099
5100<h5>Syntax:</h5>
5101<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5102 &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]5103</pre>
5104
5105<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5106<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5107 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5108
5109<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5110<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5111 non-aggregate first class value, and a type to cast it to, which must also be
5112 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5113 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5114 identical. If the source type is a pointer, the destination type must also be
5115 a pointer. This instruction supports bitwise conversion of vectors to
5116 integers and to vectors of other types (as long as they have the same
5117 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5118
5119<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5120<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5121 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5122 this conversion. The conversion is done as if the <tt>value</tt> had been
5123 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5124 be converted to other pointer types with this instruction. To convert
5125 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5126 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5127
5128<h5>Example:</h5>
5129<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5130 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5131 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5132 %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]5133</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5134
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5135</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5136
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5137</div>
5138
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5139<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5140<h3>
5141 <a name="otherops">Other Operations</a>
5142</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5143
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5144<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5145
5146<p>The instructions in this category are the "miscellaneous" instructions, which
5147 defy better classification.</p>
5148
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5149<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5150<h4>
5151 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5152</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5153
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5154<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5155
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5156<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5157<pre>
5158 &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]5159</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5160
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5161<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5162<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5163 boolean values based on comparison of its two integer, integer vector, or
5164 pointer operands.</p>
5165
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5166<h5>Arguments:</h5>
5167<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5168 the condition code indicating the kind of comparison to perform. It is not a
5169 value, just a keyword. The possible condition code are:</p>
5170
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5171<ol>
5172 <li><tt>eq</tt>: equal</li>
5173 <li><tt>ne</tt>: not equal </li>
5174 <li><tt>ugt</tt>: unsigned greater than</li>
5175 <li><tt>uge</tt>: unsigned greater or equal</li>
5176 <li><tt>ult</tt>: unsigned less than</li>
5177 <li><tt>ule</tt>: unsigned less or equal</li>
5178 <li><tt>sgt</tt>: signed greater than</li>
5179 <li><tt>sge</tt>: signed greater or equal</li>
5180 <li><tt>slt</tt>: signed less than</li>
5181 <li><tt>sle</tt>: signed less or equal</li>
5182</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5183
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5184<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5185 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5186 typed. They must also be identical types.</p>
5187
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5188<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5189<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5190 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5191 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]5192 result, as follows:</p>
5193
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5194<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5195 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5196 <tt>false</tt> otherwise. No sign interpretation is necessary or
5197 performed.</li>
5198
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5199 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5200 <tt>false</tt> otherwise. No sign interpretation is necessary or
5201 performed.</li>
5202
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5203 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5204 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5205
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5206 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5207 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5208 to <tt>op2</tt>.</li>
5209
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5210 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5211 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5212
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5213 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5214 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5215
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5216 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5217 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5218
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5219 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5220 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5221 to <tt>op2</tt>.</li>
5222
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5223 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5224 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5225
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5226 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5227 <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]5228</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5229
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5230<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5231 values are compared as if they were integers.</p>
5232
5233<p>If the operands are integer vectors, then they are compared element by
5234 element. The result is an <tt>i1</tt> vector with the same number of elements
5235 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5236
5237<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5238<pre>
5239 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5240 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5241 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5242 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5243 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5244 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5245</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5246
5247<p>Note that the code generator does not yet support vector types with
5248 the <tt>icmp</tt> instruction.</p>
5249
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5250</div>
5251
5252<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5253<h4>
5254 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5255</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5257<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5258
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5259<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5260<pre>
5261 &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]5262</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5263
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5264<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5265<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5266 values based on comparison of its operands.</p>
5267
5268<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]5269(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5270
5271<p>If the operands are floating point vectors, then the result type is a vector
5272 of boolean with the same number of elements as the operands being
5273 compared.</p>
5274
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5275<h5>Arguments:</h5>
5276<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5277 the condition code indicating the kind of comparison to perform. It is not a
5278 value, just a keyword. The possible condition code are:</p>
5279
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5280<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5281 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5282 <li><tt>oeq</tt>: ordered and equal</li>
5283 <li><tt>ogt</tt>: ordered and greater than </li>
5284 <li><tt>oge</tt>: ordered and greater than or equal</li>
5285 <li><tt>olt</tt>: ordered and less than </li>
5286 <li><tt>ole</tt>: ordered and less than or equal</li>
5287 <li><tt>one</tt>: ordered and not equal</li>
5288 <li><tt>ord</tt>: ordered (no nans)</li>
5289 <li><tt>ueq</tt>: unordered or equal</li>
5290 <li><tt>ugt</tt>: unordered or greater than </li>
5291 <li><tt>uge</tt>: unordered or greater than or equal</li>
5292 <li><tt>ult</tt>: unordered or less than </li>
5293 <li><tt>ule</tt>: unordered or less than or equal</li>
5294 <li><tt>une</tt>: unordered or not equal</li>
5295 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5296 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5297</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5298
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5299<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5300 <i>unordered</i> means that either operand may be a QNAN.</p>
5301
5302<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5303 a <a href="#t_floating">floating point</a> type or
5304 a <a href="#t_vector">vector</a> of floating point type. They must have
5305 identical types.</p>
5306
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5307<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5308<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5309 according to the condition code given as <tt>cond</tt>. If the operands are
5310 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5311 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5312 follows:</p>
5313
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5314<ol>
5315 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5316
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5317 <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]5318 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5319
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5320 <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]5321 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5322
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5323 <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]5324 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5325
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5326 <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]5327 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5328
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5329 <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]5330 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5331
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5332 <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]5333 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5334
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5335 <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]5336
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5337 <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]5338 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5339
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5340 <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]5341 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5342
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5343 <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]5344 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5345
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5346 <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]5347 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5348
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5349 <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]5350 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5351
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5352 <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]5353 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5354
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5355 <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]5356
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5357 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5358</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5359
5360<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5361<pre>
5362 &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]5363 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5364 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5365 &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]5366</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5367
5368<p>Note that the code generator does not yet support vector types with
5369 the <tt>fcmp</tt> instruction.</p>
5370
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5371</div>
5372
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5373<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5374<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5375 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5376</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5377
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5378<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5379
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5380<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5381<pre>
5382 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5383</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5384
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5385<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5386<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5387 SSA graph representing the function.</p>
5388
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5389<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5390<p>The type of the incoming values is specified with the first type field. After
5391 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5392 one pair for each predecessor basic block of the current block. Only values
5393 of <a href="#t_firstclass">first class</a> type may be used as the value
5394 arguments to the PHI node. Only labels may be used as the label
5395 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5396
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5397<p>There must be no non-phi instructions between the start of a basic block and
5398 the PHI instructions: i.e. PHI instructions must be first in a basic
5399 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5400
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5401<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5402 occur on the edge from the corresponding predecessor block to the current
5403 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5404 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5405
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5406<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5407<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5408 specified by the pair corresponding to the predecessor basic block that
5409 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5410
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5411<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5412<pre>
5413Loop: ; Infinite loop that counts from 0 on up...
5414 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5415 %nextindvar = add i32 %indvar, 1
5416 br label %Loop
5417</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5418
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5419</div>
5420
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5421<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5422<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5423 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5424</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5425
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5426<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5427
5428<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5429<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5430 &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>
5431
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5432 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5433</pre>
5434
5435<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5436<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5437 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5438
5439
5440<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5441<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5442 values indicating the condition, and two values of the
5443 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5444 vectors and the condition is a scalar, then entire vectors are selected, not
5445 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5446
5447<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5448<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5449 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5450
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5451<p>If the condition is a vector of i1, then the value arguments must be vectors
5452 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5453
5454<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5455<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5456 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5457</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5458
5459<p>Note that the code generator does not yet support conditions
5460 with vector type.</p>
5461
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5462</div>
5463
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5464<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5465<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5466 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5467</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5468
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5469<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5470
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5471<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5472<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5473 &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]5474</pre>
5475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5476<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5477<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5478
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5479<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5480<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5481
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5482<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5483 <li>The optional "tail" marker indicates that the callee function does not
5484 access any allocas or varargs in the caller. Note that calls may be
5485 marked "tail" even if they do not occur before
5486 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5487 present, the function call is eligible for tail call optimization,
5488 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5489 optimized into a jump</a>. The code generator may optimize calls marked
5490 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5491 sibling call optimization</a> when the caller and callee have
5492 matching signatures, or 2) forced tail call optimization when the
5493 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5494 <ul>
5495 <li>Caller and callee both have the calling
5496 convention <tt>fastcc</tt>.</li>
5497 <li>The call is in tail position (ret immediately follows call and ret
5498 uses value of call or is void).</li>
5499 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5500 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5501 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5502 constraints are met.</a></li>
5503 </ul>
5504 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5505
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5506 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5507 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5508 defaults to using C calling conventions. The calling convention of the
5509 call must match the calling convention of the target function, or else the
5510 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5511
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5512 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5513 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5514 '<tt>inreg</tt>' attributes are valid here.</li>
5515
5516 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5517 type of the return value. Functions that return no value are marked
5518 <tt><a href="#t_void">void</a></tt>.</li>
5519
5520 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5521 being invoked. The argument types must match the types implied by this
5522 signature. This type can be omitted if the function is not varargs and if
5523 the function type does not return a pointer to a function.</li>
5524
5525 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5526 be invoked. In most cases, this is a direct function invocation, but
5527 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5528 to function value.</li>
5529
5530 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5531 signature argument types and parameter attributes. All arguments must be
5532 of <a href="#t_firstclass">first class</a> type. If the function
5533 signature indicates the function accepts a variable number of arguments,
5534 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5535
5536 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5537 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5538 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5539</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5540
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5541<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5542<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5543 a specified function, with its incoming arguments bound to the specified
5544 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5545 function, control flow continues with the instruction after the function
5546 call, and the return value of the function is bound to the result
5547 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5548
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5549<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5550<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5551 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5552 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5553 %X = tail call i32 @foo() <i>; yields i32</i>
5554 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5555 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5556
5557 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5558 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5559 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5560 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5561 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5562 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5563</pre>
5564
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5565<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5566standard C99 library as being the C99 library functions, and may perform
5567optimizations or generate code for them under that assumption. This is
5568something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5569freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5570
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5571</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5572
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5573<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5574<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5575 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5576</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5577
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5578<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5579
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5580<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5581<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5582 &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]5583</pre>
5584
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5585<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5586<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5587 the "variable argument" area of a function call. It is used to implement the
5588 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5589
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5590<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5591<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5592 argument. It returns a value of the specified argument type and increments
5593 the <tt>va_list</tt> to point to the next argument. The actual type
5594 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5595
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5596<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5597<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5598 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5599 to the next argument. For more information, see the variable argument
5600 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5601
5602<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]5603 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5604 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5605
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5606<p><tt>va_arg</tt> is an LLVM instruction instead of
5607 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5608 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5609
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5610<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5611<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5612
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613<p>Note that the code generator does not yet fully support va_arg on many
5614 targets. Also, it does not currently support va_arg with aggregate types on
5615 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5616
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5617</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5618
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5619</div>
5620
5621</div>
5622
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5623<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5624<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5625<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5626
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5627<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5628
5629<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5630 well known names and semantics and are required to follow certain
5631 restrictions. Overall, these intrinsics represent an extension mechanism for
5632 the LLVM language that does not require changing all of the transformations
5633 in LLVM when adding to the language (or the bitcode reader/writer, the
5634 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5635
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5636<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5637 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5638 begin with this prefix. Intrinsic functions must always be external
5639 functions: you cannot define the body of intrinsic functions. Intrinsic
5640 functions may only be used in call or invoke instructions: it is illegal to
5641 take the address of an intrinsic function. Additionally, because intrinsic
5642 functions are part of the LLVM language, it is required if any are added that
5643 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5644
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5645<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5646 family of functions that perform the same operation but on different data
5647 types. Because LLVM can represent over 8 million different integer types,
5648 overloading is used commonly to allow an intrinsic function to operate on any
5649 integer type. One or more of the argument types or the result type can be
5650 overloaded to accept any integer type. Argument types may also be defined as
5651 exactly matching a previous argument's type or the result type. This allows
5652 an intrinsic function which accepts multiple arguments, but needs all of them
5653 to be of the same type, to only be overloaded with respect to a single
5654 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5655
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5656<p>Overloaded intrinsics will have the names of its overloaded argument types
5657 encoded into its function name, each preceded by a period. Only those types
5658 which are overloaded result in a name suffix. Arguments whose type is matched
5659 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5660 can take an integer of any width and returns an integer of exactly the same
5661 integer width. This leads to a family of functions such as
5662 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5663 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5664 suffix is required. Because the argument's type is matched against the return
5665 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5666
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5667<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5668 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5669
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5670<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5671<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5672 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5673</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5674
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5675<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5676
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5677<p>Variable argument support is defined in LLVM with
5678 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5679 intrinsic functions. These functions are related to the similarly named
5680 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5681
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5682<p>All of these functions operate on arguments that use a target-specific value
5683 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5684 not define what this type is, so all transformations should be prepared to
5685 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5686
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5687<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]5688 instruction and the variable argument handling intrinsic functions are
5689 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5690
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5691<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5692define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5693 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5694 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5695 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5696 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5697
5698 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5699 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5700
5701 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5702 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5703 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5704 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5705 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5706
5707 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5708 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5709 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5710}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5711
5712declare void @llvm.va_start(i8*)
5713declare void @llvm.va_copy(i8*, i8*)
5714declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5715</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5716
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5717<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5718<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5719 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5720</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5721
5722
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5723<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5724
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5725<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5726<pre>
5727 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5728</pre>
5729
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5730<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5731<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5732 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]5733
5734<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5735<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]5736
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5737<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5738<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]5739 macro available in C. In a target-dependent way, it initializes
5740 the <tt>va_list</tt> element to which the argument points, so that the next
5741 call to <tt>va_arg</tt> will produce the first variable argument passed to
5742 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5743 need to know the last argument of the function as the compiler can figure
5744 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5745
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5746</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5747
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5748<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5749<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5750 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5751</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5752
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5753<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5754
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755<h5>Syntax:</h5>
5756<pre>
5757 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5758</pre>
5759
5760<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5761<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5762 which has been initialized previously
5763 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5764 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5765
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5766<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5767<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]5768
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5769<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5770<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]5771 macro available in C. In a target-dependent way, it destroys
5772 the <tt>va_list</tt> element to which the argument points. Calls
5773 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5774 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5775 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5776
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5777</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5778
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5779<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5780<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5781 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5782</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5783
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5784<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5785
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5786<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5787<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5788 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5789</pre>
5790
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5791<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5792<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5793 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5794
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5795<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5796<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]5797 The second argument is a pointer to a <tt>va_list</tt> element to copy
5798 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5799
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5800<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5801<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]5802 macro available in C. In a target-dependent way, it copies the
5803 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5804 element. This intrinsic is necessary because
5805 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5806 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5807
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5808</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5809
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5810</div>
5811
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5812<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5813<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5814 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5815</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5816
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5817<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5818
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5819<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5820Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5821intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5822roots on the stack</a>, as well as garbage collector implementations that
5823require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5824barriers. Front-ends for type-safe garbage collected languages should generate
5825these intrinsics to make use of the LLVM garbage collectors. For more details,
5826see <a href="GarbageCollection.html">Accurate Garbage Collection with
5827LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5829<p>The garbage collection intrinsics only operate on objects in the generic
5830 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5831
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5832<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5833<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5834 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5835</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5836
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5837<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5838
5839<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5840<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5841 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5842</pre>
5843
5844<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5845<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]5846 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5847
5848<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5849<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5850 root pointer. The second pointer (which must be either a constant or a
5851 global value address) contains the meta-data to be associated with the
5852 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5853
5854<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5855<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]5856 location. At compile-time, the code generator generates information to allow
5857 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5858 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5859 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5860
5861</div>
5862
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5863<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5864<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5865 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5866</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5867
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5868<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5869
5870<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5871<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5872 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5873</pre>
5874
5875<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5876<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5877 locations, allowing garbage collector implementations that require read
5878 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5879
5880<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5881<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]5882 allocated from the garbage collector. The first object is a pointer to the
5883 start of the referenced object, if needed by the language runtime (otherwise
5884 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5885
5886<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5887<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5888 instruction, but may be replaced with substantially more complex code by the
5889 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5890 may only be used in a function which <a href="#gc">specifies a GC
5891 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5892
5893</div>
5894
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5895<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5896<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5897 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5898</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5899
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5900<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5901
5902<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5903<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5904 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5905</pre>
5906
5907<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5908<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5909 locations, allowing garbage collector implementations that require write
5910 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5911
5912<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5913<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]5914 object to store it to, and the third is the address of the field of Obj to
5915 store to. If the runtime does not require a pointer to the object, Obj may
5916 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5917
5918<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5919<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5920 instruction, but may be replaced with substantially more complex code by the
5921 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5922 may only be used in a function which <a href="#gc">specifies a GC
5923 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5924
5925</div>
5926
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5927</div>
5928
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5929<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5930<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5931 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5932</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5933
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5934<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5935
5936<p>These intrinsics are provided by LLVM to expose special features that may
5937 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5938
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5939<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5940<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5941 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5942</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5943
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5944<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5945
5946<h5>Syntax:</h5>
5947<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5948 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5949</pre>
5950
5951<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5952<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5953 target-specific value indicating the return address of the current function
5954 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5955
5956<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5957<p>The argument to this intrinsic indicates which function to return the address
5958 for. Zero indicates the calling function, one indicates its caller, etc.
5959 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5960
5961<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5962<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5963 indicating the return address of the specified call frame, or zero if it
5964 cannot be identified. The value returned by this intrinsic is likely to be
5965 incorrect or 0 for arguments other than zero, so it should only be used for
5966 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5967
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5968<p>Note that calling this intrinsic does not prevent function inlining or other
5969 aggressive transformations, so the value returned may not be that of the
5970 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5971
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5972</div>
5973
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5974<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5975<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5976 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5977</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5978
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5979<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5980
5981<h5>Syntax:</h5>
5982<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5983 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5984</pre>
5985
5986<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5987<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5988 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5989
5990<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5991<p>The argument to this intrinsic indicates which function to return the frame
5992 pointer for. Zero indicates the calling function, one indicates its caller,
5993 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5994
5995<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5996<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5997 indicating the frame address of the specified call frame, or zero if it
5998 cannot be identified. The value returned by this intrinsic is likely to be
5999 incorrect or 0 for arguments other than zero, so it should only be used for
6000 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6001
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6002<p>Note that calling this intrinsic does not prevent function inlining or other
6003 aggressive transformations, so the value returned may not be that of the
6004 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6005
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6006</div>
6007
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6008<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6009<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6010 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6011</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6012
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6013<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6014
6015<h5>Syntax:</h5>
6016<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6017 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6018</pre>
6019
6020<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6021<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6022 of the function stack, for use
6023 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6024 useful for implementing language features like scoped automatic variable
6025 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6026
6027<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6028<p>This intrinsic returns a opaque pointer value that can be passed
6029 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6030 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6031 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6032 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6033 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6034 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6035
6036</div>
6037
6038<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6039<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6040 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6041</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6042
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6043<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6044
6045<h5>Syntax:</h5>
6046<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6047 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6048</pre>
6049
6050<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6051<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6052 the function stack to the state it was in when the
6053 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6054 executed. This is useful for implementing language features like scoped
6055 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6056
6057<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6058<p>See the description
6059 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6060
6061</div>
6062
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6063<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6064<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6065 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6066</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6067
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6068<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6069
6070<h5>Syntax:</h5>
6071<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6072 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]6073</pre>
6074
6075<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6076<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6077 insert a prefetch instruction if supported; otherwise, it is a noop.
6078 Prefetches have no effect on the behavior of the program but can change its
6079 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6080
6081<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6082<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6083 specifier determining if the fetch should be for a read (0) or write (1),
6084 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6085 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6086 specifies whether the prefetch is performed on the data (1) or instruction (0)
6087 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6088 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6089
6090<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6091<p>This intrinsic does not modify the behavior of the program. In particular,
6092 prefetches cannot trap and do not produce a value. On targets that support
6093 this intrinsic, the prefetch can provide hints to the processor cache for
6094 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6095
6096</div>
6097
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6098<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6099<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6100 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6101</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6102
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6103<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6104
6105<h5>Syntax:</h5>
6106<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6107 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6108</pre>
6109
6110<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6111<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6112 Counter (PC) in a region of code to simulators and other tools. The method
6113 is target specific, but it is expected that the marker will use exported
6114 symbols to transmit the PC of the marker. The marker makes no guarantees
6115 that it will remain with any specific instruction after optimizations. It is
6116 possible that the presence of a marker will inhibit optimizations. The
6117 intended use is to be inserted after optimizations to allow correlations of
6118 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6119
6120<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6121<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6122
6123<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6124<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6125 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6126
6127</div>
6128
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6129<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6130<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6131 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6132</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6133
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6134<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6135
6136<h5>Syntax:</h5>
6137<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6138 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6139</pre>
6140
6141<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6142<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6143 counter register (or similar low latency, high accuracy clocks) on those
6144 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6145 should map to RPCC. As the backing counters overflow quickly (on the order
6146 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6147
6148<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6149<p>When directly supported, reading the cycle counter should not modify any
6150 memory. Implementations are allowed to either return a application specific
6151 value or a system wide value. On backends without support, this is lowered
6152 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6153
6154</div>
6155
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6156</div>
6157
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6158<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6159<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6160 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6161</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6162
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6163<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6164
6165<p>LLVM provides intrinsics for a few important standard C library functions.
6166 These intrinsics allow source-language front-ends to pass information about
6167 the alignment of the pointer arguments to the code generator, providing
6168 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6169
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6170<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6171<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6172 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6173</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6174
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6175<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6176
6177<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6178<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]6179 integer bit width and for different address spaces. Not all targets support
6180 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6181
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6182<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6183 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]6184 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6185 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]6186 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6187</pre>
6188
6189<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6190<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6191 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6192
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6193<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6194 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6195 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6196
6197<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6198
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6199<p>The first argument is a pointer to the destination, the second is a pointer
6200 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6201 number of bytes to copy, the fourth argument is the alignment of the
6202 source and destination locations, and the fifth is a boolean indicating a
6203 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6204
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6205<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]6206 then the caller guarantees that both the source and destination pointers are
6207 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6208
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6209<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6210 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6211 The detailed access behavior is not very cleanly specified and it is unwise
6212 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6213
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6214<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6215
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6216<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6217 source location to the destination location, which are not allowed to
6218 overlap. It copies "len" bytes of memory over. If the argument is known to
6219 be aligned to some boundary, this can be specified as the fourth argument,
6220 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6221
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6222</div>
6223
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6224<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6225<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6226 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6227</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6228
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6229<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6230
6231<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6232<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]6233 width and for different address space. Not all targets support all bit
6234 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6235
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6236<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6237 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]6238 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6239 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]6240 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6241</pre>
6242
6243<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6244<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6245 source location to the destination location. It is similar to the
6246 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6247 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6248
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6249<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6250 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6251 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6252
6253<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6254
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6255<p>The first argument is a pointer to the destination, the second is a pointer
6256 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6257 number of bytes to copy, the fourth argument is the alignment of the
6258 source and destination locations, and the fifth is a boolean indicating a
6259 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6260
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6261<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]6262 then the caller guarantees that the source and destination pointers are
6263 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6264
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6265<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6266 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6267 The detailed access behavior is not very cleanly specified and it is unwise
6268 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6269
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6270<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6271
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6272<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6273 source location to the destination location, which may overlap. It copies
6274 "len" bytes of memory over. If the argument is known to be aligned to some
6275 boundary, this can be specified as the fourth argument, otherwise it should
6276 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6277
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6278</div>
6279
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6280<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6281<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6282 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6283</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6284
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6285<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6286
6287<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6288<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]6289 width and for different address spaces. However, not all targets support all
6290 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6291
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6292<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6293 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6294 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6295 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6296 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6297</pre>
6298
6299<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6300<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6301 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6302
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6303<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6304 intrinsic does not return a value and takes extra alignment/volatile
6305 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6306
6307<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6308<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]6309 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6310 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6311 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6312
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6313<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]6314 then the caller guarantees that the destination pointer is aligned to that
6315 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6316
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6317<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6318 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6319 The detailed access behavior is not very cleanly specified and it is unwise
6320 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6321
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6322<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6323<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6324 at the destination location. If the argument is known to be aligned to some
6325 boundary, this can be specified as the fourth argument, otherwise it should
6326 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6327
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6328</div>
6329
Chris Lattner32006282004-06-11 02:28:03 +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_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6333</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6334
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6335<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6336
6337<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6338<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6339 floating point or vector of floating point type. Not all targets support all
6340 types however.</p>
6341
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6342<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6343 declare float @llvm.sqrt.f32(float %Val)
6344 declare double @llvm.sqrt.f64(double %Val)
6345 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6346 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6347 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6348</pre>
6349
6350<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6351<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6352 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6353 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6354 behavior for negative numbers other than -0.0 (which allows for better
6355 optimization, because there is no need to worry about errno being
6356 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]6357
6358<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6359<p>The argument and return value are floating point numbers of the same
6360 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6361
6362<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6363<p>This function returns the sqrt of the specified operand if it is a
6364 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6365
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6366</div>
6367
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6368<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6369<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6370 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6371</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6372
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6373<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6374
6375<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6376<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6377 floating point or vector of floating point type. Not all targets support all
6378 types however.</p>
6379
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6380<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6381 declare float @llvm.powi.f32(float %Val, i32 %power)
6382 declare double @llvm.powi.f64(double %Val, i32 %power)
6383 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6384 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6385 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6386</pre>
6387
6388<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6389<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6390 specified (positive or negative) power. The order of evaluation of
6391 multiplications is not defined. When a vector of floating point type is
6392 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6393
6394<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6395<p>The second argument is an integer power, and the first is a value to raise to
6396 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6397
6398<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6399<p>This function returns the first value raised to the second power with an
6400 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6401
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6402</div>
6403
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6404<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6405<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6406 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6407</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6408
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6409<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6410
6411<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6412<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6413 floating point or vector of floating point type. Not all targets support all
6414 types however.</p>
6415
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6416<pre>
6417 declare float @llvm.sin.f32(float %Val)
6418 declare double @llvm.sin.f64(double %Val)
6419 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6420 declare fp128 @llvm.sin.f128(fp128 %Val)
6421 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6422</pre>
6423
6424<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6425<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6426
6427<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6428<p>The argument and return value are floating point numbers of the same
6429 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6430
6431<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6432<p>This function returns the sine of the specified operand, returning the same
6433 values as the libm <tt>sin</tt> functions would, and handles error conditions
6434 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6435
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6436</div>
6437
6438<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6439<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6440 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6441</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6442
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6443<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6444
6445<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6446<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6447 floating point or vector of floating point type. Not all targets support all
6448 types however.</p>
6449
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6450<pre>
6451 declare float @llvm.cos.f32(float %Val)
6452 declare double @llvm.cos.f64(double %Val)
6453 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6454 declare fp128 @llvm.cos.f128(fp128 %Val)
6455 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6456</pre>
6457
6458<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6459<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6460
6461<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6462<p>The argument and return value are floating point numbers of the same
6463 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6464
6465<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6466<p>This function returns the cosine of the specified operand, returning the same
6467 values as the libm <tt>cos</tt> functions would, and handles error conditions
6468 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6469
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6470</div>
6471
6472<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6473<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6474 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6475</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6476
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6477<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6478
6479<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6480<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6481 floating point or vector of floating point type. Not all targets support all
6482 types however.</p>
6483
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6484<pre>
6485 declare float @llvm.pow.f32(float %Val, float %Power)
6486 declare double @llvm.pow.f64(double %Val, double %Power)
6487 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6488 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6489 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6490</pre>
6491
6492<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6493<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6494 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6495
6496<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6497<p>The second argument is a floating point power, and the first is a value to
6498 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6499
6500<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6501<p>This function returns the first value raised to the second power, returning
6502 the same values as the libm <tt>pow</tt> functions would, and handles error
6503 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6504
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6505</div>
6506
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6507</div>
6508
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6509<!-- _______________________________________________________________________ -->
6510<h4>
6511 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6512</h4>
6513
6514<div>
6515
6516<h5>Syntax:</h5>
6517<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6518 floating point or vector of floating point type. Not all targets support all
6519 types however.</p>
6520
6521<pre>
6522 declare float @llvm.exp.f32(float %Val)
6523 declare double @llvm.exp.f64(double %Val)
6524 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6525 declare fp128 @llvm.exp.f128(fp128 %Val)
6526 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6527</pre>
6528
6529<h5>Overview:</h5>
6530<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6531
6532<h5>Arguments:</h5>
6533<p>The argument and return value are floating point numbers of the same
6534 type.</p>
6535
6536<h5>Semantics:</h5>
6537<p>This function returns the same values as the libm <tt>exp</tt> functions
6538 would, and handles error conditions in the same way.</p>
6539
6540</div>
6541
6542<!-- _______________________________________________________________________ -->
6543<h4>
6544 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6545</h4>
6546
6547<div>
6548
6549<h5>Syntax:</h5>
6550<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6551 floating point or vector of floating point type. Not all targets support all
6552 types however.</p>
6553
6554<pre>
6555 declare float @llvm.log.f32(float %Val)
6556 declare double @llvm.log.f64(double %Val)
6557 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6558 declare fp128 @llvm.log.f128(fp128 %Val)
6559 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6560</pre>
6561
6562<h5>Overview:</h5>
6563<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6564
6565<h5>Arguments:</h5>
6566<p>The argument and return value are floating point numbers of the same
6567 type.</p>
6568
6569<h5>Semantics:</h5>
6570<p>This function returns the same values as the libm <tt>log</tt> functions
6571 would, and handles error conditions in the same way.</p>
6572
6573</div>
6574
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6575<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6576<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6577 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6578</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6579
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6580<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6581
6582<p>LLVM provides intrinsics for a few important bit manipulation operations.
6583 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6584
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6585<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6586<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6587 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6588</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6589
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6590<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6591
6592<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6593<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6594 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6595
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6596<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6597 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6598 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6599 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6600</pre>
6601
6602<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6603<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6604 values with an even number of bytes (positive multiple of 16 bits). These
6605 are useful for performing operations on data that is not in the target's
6606 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6607
6608<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6609<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6610 and low byte of the input i16 swapped. Similarly,
6611 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6612 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6613 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6614 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6615 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6616 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6617
6618</div>
6619
6620<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6621<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6622 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6623</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6624
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6625<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6626
6627<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6628<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6629 width. Not all targets support all bit widths however.</p>
6630
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6631<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6632 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6633 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6634 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6635 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6636 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6637</pre>
6638
6639<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6641 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6642
6643<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6644<p>The only argument is the value to be counted. The argument may be of any
6645 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6646
6647<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6648<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6649
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6650</div>
6651
6652<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6653<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6654 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6655</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6656
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6657<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6658
6659<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6660<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6661 integer bit width. Not all targets support all bit widths however.</p>
6662
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6663<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6664 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6665 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6666 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6667 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6668 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6669</pre>
6670
6671<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6672<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6673 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6674
6675<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6676<p>The only argument is the value to be counted. The argument may be of any
6677 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6678
6679<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6680<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6681 zeros in a variable. If the src == 0 then the result is the size in bits of
6682 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6683
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6684</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6685
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6686<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6687<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6688 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6689</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6690
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6691<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6692
6693<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6694<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6695 integer bit width. Not all targets support all bit widths however.</p>
6696
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6697<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6698 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6699 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6700 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6701 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6702 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6703</pre>
6704
6705<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6706<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6707 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6708
6709<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6710<p>The only argument is the value to be counted. The argument may be of any
6711 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6712
6713<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6714<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6715 zeros in a variable. If the src == 0 then the result is the size in bits of
6716 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6717
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6718</div>
6719
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6720</div>
6721
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6722<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6723<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6724 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6725</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6726
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6727<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6728
6729<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6730
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6731<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6732<h4>
6733 <a name="int_sadd_overflow">
6734 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6735 </a>
6736</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6737
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6738<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6739
6740<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6741<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]6742 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6743
6744<pre>
6745 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6746 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6747 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6748</pre>
6749
6750<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6751<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6752 a signed addition of the two arguments, and indicate whether an overflow
6753 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6754
6755<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6756<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]6757 be of integer types of any bit width, but they must have the same bit
6758 width. The second element of the result structure must be of
6759 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6760 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6761
6762<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6763<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6764 a signed addition of the two variables. They return a structure &mdash; the
6765 first element of which is the signed summation, and the second element of
6766 which is a bit specifying if the signed summation resulted in an
6767 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6768
6769<h5>Examples:</h5>
6770<pre>
6771 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6772 %sum = extractvalue {i32, i1} %res, 0
6773 %obit = extractvalue {i32, i1} %res, 1
6774 br i1 %obit, label %overflow, label %normal
6775</pre>
6776
6777</div>
6778
6779<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6780<h4>
6781 <a name="int_uadd_overflow">
6782 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6783 </a>
6784</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6785
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6786<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6787
6788<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6789<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]6790 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6791
6792<pre>
6793 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6794 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6795 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6796</pre>
6797
6798<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6799<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6800 an unsigned addition of the two arguments, and indicate whether a carry
6801 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6802
6803<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6804<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]6805 be of integer types of any bit width, but they must have the same bit
6806 width. The second element of the result structure must be of
6807 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6808 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6809
6810<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6811<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6812 an unsigned addition of the two arguments. They return a structure &mdash;
6813 the first element of which is the sum, and the second element of which is a
6814 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6815
6816<h5>Examples:</h5>
6817<pre>
6818 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6819 %sum = extractvalue {i32, i1} %res, 0
6820 %obit = extractvalue {i32, i1} %res, 1
6821 br i1 %obit, label %carry, label %normal
6822</pre>
6823
6824</div>
6825
6826<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6827<h4>
6828 <a name="int_ssub_overflow">
6829 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6830 </a>
6831</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6832
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6833<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6834
6835<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6836<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]6837 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6838
6839<pre>
6840 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6841 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6842 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6843</pre>
6844
6845<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6846<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6847 a signed subtraction of the two arguments, and indicate whether an overflow
6848 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6849
6850<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6851<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]6852 be of integer types of any bit width, but they must have the same bit
6853 width. The second element of the result structure must be of
6854 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6855 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6856
6857<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6858<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6859 a signed subtraction of the two arguments. They return a structure &mdash;
6860 the first element of which is the subtraction, and the second element of
6861 which is a bit specifying if the signed subtraction resulted in an
6862 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6863
6864<h5>Examples:</h5>
6865<pre>
6866 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6867 %sum = extractvalue {i32, i1} %res, 0
6868 %obit = extractvalue {i32, i1} %res, 1
6869 br i1 %obit, label %overflow, label %normal
6870</pre>
6871
6872</div>
6873
6874<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6875<h4>
6876 <a name="int_usub_overflow">
6877 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6878 </a>
6879</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6880
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6881<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6882
6883<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6884<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]6885 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6886
6887<pre>
6888 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6889 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6890 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6891</pre>
6892
6893<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6894<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6895 an unsigned subtraction of the two arguments, and indicate whether an
6896 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6897
6898<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6899<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]6900 be of integer types of any bit width, but they must have the same bit
6901 width. The second element of the result structure must be of
6902 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6903 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6904
6905<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6906<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6907 an unsigned subtraction of the two arguments. They return a structure &mdash;
6908 the first element of which is the subtraction, and the second element of
6909 which is a bit specifying if the unsigned subtraction resulted in an
6910 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6911
6912<h5>Examples:</h5>
6913<pre>
6914 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6915 %sum = extractvalue {i32, i1} %res, 0
6916 %obit = extractvalue {i32, i1} %res, 1
6917 br i1 %obit, label %overflow, label %normal
6918</pre>
6919
6920</div>
6921
6922<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6923<h4>
6924 <a name="int_smul_overflow">
6925 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6926 </a>
6927</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6928
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6929<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6930
6931<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6932<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]6933 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6934
6935<pre>
6936 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6937 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6938 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6939</pre>
6940
6941<h5>Overview:</h5>
6942
6943<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6944 a signed multiplication of the two arguments, and indicate whether an
6945 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6946
6947<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6948<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]6949 be of integer types of any bit width, but they must have the same bit
6950 width. The second element of the result structure must be of
6951 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6952 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6953
6954<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6955<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6956 a signed multiplication of the two arguments. They return a structure &mdash;
6957 the first element of which is the multiplication, and the second element of
6958 which is a bit specifying if the signed multiplication resulted in an
6959 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6960
6961<h5>Examples:</h5>
6962<pre>
6963 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6964 %sum = extractvalue {i32, i1} %res, 0
6965 %obit = extractvalue {i32, i1} %res, 1
6966 br i1 %obit, label %overflow, label %normal
6967</pre>
6968
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6969</div>
6970
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6971<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6972<h4>
6973 <a name="int_umul_overflow">
6974 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
6975 </a>
6976</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6977
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6978<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6979
6980<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6981<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]6982 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6983
6984<pre>
6985 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6986 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6987 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6988</pre>
6989
6990<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6991<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6992 a unsigned multiplication of the two arguments, and indicate whether an
6993 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6994
6995<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6996<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]6997 be of integer types of any bit width, but they must have the same bit
6998 width. The second element of the result structure must be of
6999 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7000 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7001
7002<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7003<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7004 an unsigned multiplication of the two arguments. They return a structure
7005 &mdash; the first element of which is the multiplication, and the second
7006 element of which is a bit specifying if the unsigned multiplication resulted
7007 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7008
7009<h5>Examples:</h5>
7010<pre>
7011 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7012 %sum = extractvalue {i32, i1} %res, 0
7013 %obit = extractvalue {i32, i1} %res, 1
7014 br i1 %obit, label %overflow, label %normal
7015</pre>
7016
7017</div>
7018
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7019</div>
7020
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7021<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7022<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7023 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7024</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7025
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7026<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7027
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7028<p>Half precision floating point is a storage-only format. This means that it is
7029 a dense encoding (in memory) but does not support computation in the
7030 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7031
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7032<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7033 value as an i16, then convert it to float with <a
7034 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7035 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7036 double etc). To store the value back to memory, it is first converted to
7037 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7038 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7039 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7040
7041<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7042<h4>
7043 <a name="int_convert_to_fp16">
7044 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7045 </a>
7046</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7047
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7048<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7049
7050<h5>Syntax:</h5>
7051<pre>
7052 declare i16 @llvm.convert.to.fp16(f32 %a)
7053</pre>
7054
7055<h5>Overview:</h5>
7056<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7057 a conversion from single precision floating point format to half precision
7058 floating point format.</p>
7059
7060<h5>Arguments:</h5>
7061<p>The intrinsic function contains single argument - the value to be
7062 converted.</p>
7063
7064<h5>Semantics:</h5>
7065<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7066 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7067 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7068 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7069
7070<h5>Examples:</h5>
7071<pre>
7072 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7073 store i16 %res, i16* @x, align 2
7074</pre>
7075
7076</div>
7077
7078<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7079<h4>
7080 <a name="int_convert_from_fp16">
7081 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7082 </a>
7083</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7084
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7085<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7086
7087<h5>Syntax:</h5>
7088<pre>
7089 declare f32 @llvm.convert.from.fp16(i16 %a)
7090</pre>
7091
7092<h5>Overview:</h5>
7093<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7094 a conversion from half precision floating point format to single precision
7095 floating point format.</p>
7096
7097<h5>Arguments:</h5>
7098<p>The intrinsic function contains single argument - the value to be
7099 converted.</p>
7100
7101<h5>Semantics:</h5>
7102<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7103 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7104 precision floating point format. The input half-float value is represented by
7105 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7106
7107<h5>Examples:</h5>
7108<pre>
7109 %a = load i16* @x, align 2
7110 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7111</pre>
7112
7113</div>
7114
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7115</div>
7116
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7117<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7118<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7119 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7120</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7121
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7122<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7123
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7124<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7125 prefix), are described in
7126 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7127 Level Debugging</a> document.</p>
7128
7129</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7130
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7131<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7132<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7133 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7134</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7135
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7136<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7137
7138<p>The LLVM exception handling intrinsics (which all start with
7139 <tt>llvm.eh.</tt> prefix), are described in
7140 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7141 Handling</a> document.</p>
7142
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7143</div>
7144
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7145<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7146<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7147 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7148</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7149
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7150<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7151
7152<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7153 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7154 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7155 function pointer lacking the nest parameter - the caller does not need to
7156 provide a value for it. Instead, the value to use is stored in advance in a
7157 "trampoline", a block of memory usually allocated on the stack, which also
7158 contains code to splice the nest value into the argument list. This is used
7159 to implement the GCC nested function address extension.</p>
7160
7161<p>For example, if the function is
7162 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7163 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7164 follows:</p>
7165
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7166<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7167 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7168 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7169 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7170 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7171</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7172
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7173<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7174 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7175
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7176<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7177<h4>
7178 <a name="int_it">
7179 '<tt>llvm.init.trampoline</tt>' Intrinsic
7180 </a>
7181</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7182
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7183<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7184
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7185<h5>Syntax:</h5>
7186<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7187 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7188</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7189
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7190<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7191<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7192 function pointer suitable for executing it.</p>
7193
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7194<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7195<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7196 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7197 sufficiently aligned block of memory; this memory is written to by the
7198 intrinsic. Note that the size and the alignment are target-specific - LLVM
7199 currently provides no portable way of determining them, so a front-end that
7200 generates this intrinsic needs to have some target-specific knowledge.
7201 The <tt>func</tt> argument must hold a function bitcast to
7202 an <tt>i8*</tt>.</p>
7203
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7204<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7205<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7206 dependent code, turning it into a function. A pointer to this function is
7207 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7208 function pointer type</a> before being called. The new function's signature
7209 is the same as that of <tt>func</tt> with any arguments marked with
7210 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7211 is allowed, and it must be of pointer type. Calling the new function is
7212 equivalent to calling <tt>func</tt> with the same argument list, but
7213 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7214 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7215 by <tt>tramp</tt> is modified, then the effect of any later call to the
7216 returned function pointer is undefined.</p>
7217
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7218</div>
7219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7220</div>
7221
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7222<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7223<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7224 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7225</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7226
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7227<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7228
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7229<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7230 hardware constructs for atomic operations and memory synchronization. This
7231 provides an interface to the hardware, not an interface to the programmer. It
7232 is aimed at a low enough level to allow any programming models or APIs
7233 (Application Programming Interfaces) which need atomic behaviors to map
7234 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7235 hardware provides a "universal IR" for source languages, it also provides a
7236 starting point for developing a "universal" atomic operation and
7237 synchronization IR.</p>
7238
7239<p>These do <em>not</em> form an API such as high-level threading libraries,
7240 software transaction memory systems, atomic primitives, and intrinsic
7241 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7242 application libraries. The hardware interface provided by LLVM should allow
7243 a clean implementation of all of these APIs and parallel programming models.
7244 No one model or paradigm should be selected above others unless the hardware
7245 itself ubiquitously does so.</p>
7246
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7247<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7248<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7249 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7250</h4>
7251
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7252<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7253<h5>Syntax:</h5>
7254<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7255 declare void @llvm.memory.barrier(i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt;)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7256</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7257
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7258<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7259<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7260 specific pairs of memory access types.</p>
7261
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7262<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7263<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7264 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7265 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7266 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7267
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7268<ul>
7269 <li><tt>ll</tt>: load-load barrier</li>
7270 <li><tt>ls</tt>: load-store barrier</li>
7271 <li><tt>sl</tt>: store-load barrier</li>
7272 <li><tt>ss</tt>: store-store barrier</li>
7273 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7274</ul>
7275
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7276<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7277<p>This intrinsic causes the system to enforce some ordering constraints upon
7278 the loads and stores of the program. This barrier does not
7279 indicate <em>when</em> any events will occur, it only enforces
7280 an <em>order</em> in which they occur. For any of the specified pairs of load
7281 and store operations (f.ex. load-load, or store-load), all of the first
7282 operations preceding the barrier will complete before any of the second
7283 operations succeeding the barrier begin. Specifically the semantics for each
7284 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7285
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7286<ul>
7287 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7288 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7289 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7290 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7291 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7292 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7293 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7294 load after the barrier begins.</li>
7295</ul>
7296
7297<p>These semantics are applied with a logical "and" behavior when more than one
7298 is enabled in a single memory barrier intrinsic.</p>
7299
7300<p>Backends may implement stronger barriers than those requested when they do
7301 not support as fine grained a barrier as requested. Some architectures do
7302 not need all types of barriers and on such architectures, these become
7303 noops.</p>
7304
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7305<h5>Example:</h5>
7306<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7307%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7308%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7309 store i32 4, %ptr
7310
7311%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame^]7312 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7313 <i>; guarantee the above finishes</i>
7314 store i32 8, %ptr <i>; before this begins</i>
7315</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7316
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7317</div>
7318
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7319<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7320<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7321 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7322</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7323
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7324<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7325
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7326<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7327<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7328 any integer bit width and for different address spaces. Not all targets
7329 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7330
7331<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7332 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7333 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7334 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7335 declare i64 @llvm.atomic.cmp.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7336</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7337
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7338<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7339<p>This loads a value in memory and compares it to a given value. If they are
7340 equal, it stores a new value into the memory.</p>
7341
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7342<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7343<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7344 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7345 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7346 this integer type. While any bit width integer may be used, targets may only
7347 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7348
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7349<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7350<p>This entire intrinsic must be executed atomically. It first loads the value
7351 in memory pointed to by <tt>ptr</tt> and compares it with the
7352 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7353 memory. The loaded value is yielded in all cases. This provides the
7354 equivalent of an atomic compare-and-swap operation within the SSA
7355 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7356
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7357<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7358<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7359%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7360%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7361 store i32 4, %ptr
7362
7363%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7364%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7365 <i>; yields {i32}:result1 = 4</i>
7366%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7367%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7368
7369%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7370%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7371 <i>; yields {i32}:result2 = 8</i>
7372%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7373
7374%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7375</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7376
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7377</div>
7378
7379<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7380<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7381 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7382</h4>
7383
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7384<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7385<h5>Syntax:</h5>
7386
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7387<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7388 integer bit width. Not all targets support all bit widths however.</p>
7389
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7390<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7391 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7392 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7393 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7394 declare i64 @llvm.atomic.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7395</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7396
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7397<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7398<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7399 the value from memory. It then stores the value in <tt>val</tt> in the memory
7400 at <tt>ptr</tt>.</p>
7401
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7402<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7403<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7404 the <tt>val</tt> argument and the result must be integers of the same bit
7405 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7406 integer type. The targets may only lower integer representations they
7407 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7408
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7409<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7410<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7411 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7412 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7413
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7414<h5>Examples:</h5>
7415<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7416%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7417%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7418 store i32 4, %ptr
7419
7420%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7421%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7422 <i>; yields {i32}:result1 = 4</i>
7423%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7424%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7425
7426%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7427%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7428 <i>; yields {i32}:result2 = 8</i>
7429
7430%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7431%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7432</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7433
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7434</div>
7435
7436<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7437<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7438 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7439</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7440
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7441<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7442
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7443<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7444<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7445 any integer bit width. Not all targets support all bit widths however.</p>
7446
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7447<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7448 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7449 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7450 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7451 declare i64 @llvm.atomic.load.add.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7452</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7453
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7454<h5>Overview:</h5>
7455<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7456 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7457
7458<h5>Arguments:</h5>
7459<p>The intrinsic takes two arguments, the first a pointer to an integer value
7460 and the second an integer value. The result is also an integer value. These
7461 integer types can have any bit width, but they must all have the same bit
7462 width. The targets may only lower integer representations they support.</p>
7463
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7464<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7465<p>This intrinsic does a series of operations atomically. It first loads the
7466 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7467 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7468
7469<h5>Examples:</h5>
7470<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7471%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7472%ptr = bitcast i8* %mallocP to i32*
7473 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7474%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7475 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7476%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7477 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7478%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7479 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7480%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7481</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7482
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7483</div>
7484
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7485<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7486<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7487 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7488</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7489
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7490<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7491
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7492<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7493<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7494 any integer bit width and for different address spaces. Not all targets
7495 support all bit widths however.</p>
7496
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7497<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7498 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7499 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7500 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7501 declare i64 @llvm.atomic.load.sub.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7502</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7503
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7504<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7505<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7506 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7507
7508<h5>Arguments:</h5>
7509<p>The intrinsic takes two arguments, the first a pointer to an integer value
7510 and the second an integer value. The result is also an integer value. These
7511 integer types can have any bit width, but they must all have the same bit
7512 width. The targets may only lower integer representations they support.</p>
7513
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7514<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7515<p>This intrinsic does a series of operations atomically. It first loads the
7516 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7517 result to <tt>ptr</tt>. It yields the original value stored
7518 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7519
7520<h5>Examples:</h5>
7521<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7522%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7523%ptr = bitcast i8* %mallocP to i32*
7524 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7525%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7526 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7527%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7528 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7529%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7530 <i>; yields {i32}:result3 = 2</i>
7531%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7532</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7533
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7534</div>
7535
7536<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7537<h4>
7538 <a name="int_atomic_load_and">
7539 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7540 </a>
7541 <br>
7542 <a name="int_atomic_load_nand">
7543 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7544 </a>
7545 <br>
7546 <a name="int_atomic_load_or">
7547 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7548 </a>
7549 <br>
7550 <a name="int_atomic_load_xor">
7551 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7552 </a>
7553</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7554
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7555<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7556
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7557<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7558<p>These are overloaded intrinsics. You can
7559 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7560 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7561 bit width and for different address spaces. Not all targets support all bit
7562 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7563
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7564<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7565 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7566 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7567 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7568 declare i64 @llvm.atomic.load.and.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7569</pre>
7570
7571<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7572 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7573 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7574 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7575 declare i64 @llvm.atomic.load.or.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7576</pre>
7577
7578<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7579 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7580 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7581 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7582 declare i64 @llvm.atomic.load.nand.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7583</pre>
7584
7585<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7586 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7587 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7588 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7589 declare i64 @llvm.atomic.load.xor.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7590</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7591
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7592<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7593<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7594 the value stored in memory at <tt>ptr</tt>. It yields the original value
7595 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7596
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7597<h5>Arguments:</h5>
7598<p>These intrinsics take two arguments, the first a pointer to an integer value
7599 and the second an integer value. The result is also an integer value. These
7600 integer types can have any bit width, but they must all have the same bit
7601 width. The targets may only lower integer representations they support.</p>
7602
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7603<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7604<p>These intrinsics does a series of operations atomically. They first load the
7605 value stored at <tt>ptr</tt>. They then do the bitwise
7606 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7607 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7608
7609<h5>Examples:</h5>
7610<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7611%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7612%ptr = bitcast i8* %mallocP to i32*
7613 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7614%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7615 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7616%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7617 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7618%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7619 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7620%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7621 <i>; yields {i32}:result3 = FF</i>
7622%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7623</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7624
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7625</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7626
7627<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7628<h4>
7629 <a name="int_atomic_load_max">
7630 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7631 </a>
7632 <br>
7633 <a name="int_atomic_load_min">
7634 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7635 </a>
7636 <br>
7637 <a name="int_atomic_load_umax">
7638 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7639 </a>
7640 <br>
7641 <a name="int_atomic_load_umin">
7642 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7643 </a>
7644</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7645
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7646<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7647
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7648<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7649<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7650 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7651 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7652 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7653
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7654<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7655 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7656 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7657 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7658 declare i64 @llvm.atomic.load.max.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7659</pre>
7660
7661<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7662 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7663 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7664 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7665 declare i64 @llvm.atomic.load.min.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7666</pre>
7667
7668<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7669 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7670 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7671 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7672 declare i64 @llvm.atomic.load.umax.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7673</pre>
7674
7675<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7676 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7677 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7678 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7679 declare i64 @llvm.atomic.load.umin.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7680</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7681
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7682<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7683<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7684 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7685 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7686
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7687<h5>Arguments:</h5>
7688<p>These intrinsics take two arguments, the first a pointer to an integer value
7689 and the second an integer value. The result is also an integer value. These
7690 integer types can have any bit width, but they must all have the same bit
7691 width. The targets may only lower integer representations they support.</p>
7692
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7693<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7694<p>These intrinsics does a series of operations atomically. They first load the
7695 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7696 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7697 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7698
7699<h5>Examples:</h5>
7700<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7701%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7702%ptr = bitcast i8* %mallocP to i32*
7703 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7704%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7705 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7706%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7707 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7708%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7709 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7710%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7711 <i>; yields {i32}:result3 = 8</i>
7712%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7713</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7714
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7715</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7716
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7717</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7718
7719<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7720<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7721 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7722</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7723
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7724<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7725
7726<p>This class of intrinsics exists to information about the lifetime of memory
7727 objects and ranges where variables are immutable.</p>
7728
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7729<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7730<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7731 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7732</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7733
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7734<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7735
7736<h5>Syntax:</h5>
7737<pre>
7738 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7739</pre>
7740
7741<h5>Overview:</h5>
7742<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7743 object's lifetime.</p>
7744
7745<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7746<p>The first argument is a constant integer representing the size of the
7747 object, or -1 if it is variable sized. The second argument is a pointer to
7748 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7749
7750<h5>Semantics:</h5>
7751<p>This intrinsic indicates that before this point in the code, the value of the
7752 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]7753 never be used and has an undefined value. A load from the pointer that
7754 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7755 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7756
7757</div>
7758
7759<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7760<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7761 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7762</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7763
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7764<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7765
7766<h5>Syntax:</h5>
7767<pre>
7768 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7769</pre>
7770
7771<h5>Overview:</h5>
7772<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7773 object's lifetime.</p>
7774
7775<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7776<p>The first argument is a constant integer representing the size of the
7777 object, or -1 if it is variable sized. The second argument is a pointer to
7778 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7779
7780<h5>Semantics:</h5>
7781<p>This intrinsic indicates that after this point in the code, the value of the
7782 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7783 never be used and has an undefined value. Any stores into the memory object
7784 following this intrinsic may be removed as dead.
7785
7786</div>
7787
7788<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7789<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7790 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7791</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7792
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7793<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7794
7795<h5>Syntax:</h5>
7796<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]7797 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7798</pre>
7799
7800<h5>Overview:</h5>
7801<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7802 a memory object will not change.</p>
7803
7804<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7805<p>The first argument is a constant integer representing the size of the
7806 object, or -1 if it is variable sized. The second argument is a pointer to
7807 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7808
7809<h5>Semantics:</h5>
7810<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7811 the return value, the referenced memory location is constant and
7812 unchanging.</p>
7813
7814</div>
7815
7816<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7817<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7818 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7819</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7820
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7821<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7822
7823<h5>Syntax:</h5>
7824<pre>
7825 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7826</pre>
7827
7828<h5>Overview:</h5>
7829<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7830 a memory object are mutable.</p>
7831
7832<h5>Arguments:</h5>
7833<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7834 The second argument is a constant integer representing the size of the
7835 object, or -1 if it is variable sized and the third argument is a pointer
7836 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7837
7838<h5>Semantics:</h5>
7839<p>This intrinsic indicates that the memory is mutable again.</p>
7840
7841</div>
7842
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7843</div>
7844
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7845<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7846<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7847 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7848</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7849
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7850<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7851
7852<p>This class of intrinsics is designed to be generic and has no specific
7853 purpose.</p>
7854
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7855<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7856<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7857 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7858</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7859
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7860<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7861
7862<h5>Syntax:</h5>
7863<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7864 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]7865</pre>
7866
7867<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7868<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7869
7870<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7871<p>The first argument is a pointer to a value, the second is a pointer to a
7872 global string, the third is a pointer to a global string which is the source
7873 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7874
7875<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7876<p>This intrinsic allows annotation of local variables with arbitrary strings.
7877 This can be useful for special purpose optimizations that want to look for
7878 these annotations. These have no other defined use, they are ignored by code
7879 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7880
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7881</div>
7882
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7883<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7884<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7885 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7886</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7887
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7888<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7889
7890<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7891<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7892 any integer bit width.</p>
7893
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7894<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7895 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7896 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7897 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7898 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7899 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]7900</pre>
7901
7902<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7903<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7904
7905<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7906<p>The first argument is an integer value (result of some expression), the
7907 second is a pointer to a global string, the third is a pointer to a global
7908 string which is the source file name, and the last argument is the line
7909 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7910
7911<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7912<p>This intrinsic allows annotations to be put on arbitrary expressions with
7913 arbitrary strings. This can be useful for special purpose optimizations that
7914 want to look for these annotations. These have no other defined use, they
7915 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7916
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7917</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7918
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7919<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7920<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7921 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7922</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7923
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7924<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7925
7926<h5>Syntax:</h5>
7927<pre>
7928 declare void @llvm.trap()
7929</pre>
7930
7931<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7932<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7933
7934<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7935<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7936
7937<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7938<p>This intrinsics is lowered to the target dependent trap instruction. If the
7939 target does not have a trap instruction, this intrinsic will be lowered to
7940 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7941
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7942</div>
7943
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7944<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7945<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7946 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7947</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7948
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7949<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7950
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7951<h5>Syntax:</h5>
7952<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7953 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7954</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7955
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7956<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7957<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7958 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7959 ensure that it is placed on the stack before local variables.</p>
7960
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7961<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7962<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7963 arguments. The first argument is the value loaded from the stack
7964 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7965 that has enough space to hold the value of the guard.</p>
7966
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7967<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7968<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7969 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7970 stack. This is to ensure that if a local variable on the stack is
7971 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7972 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7973 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7974 function.</p>
7975
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7976</div>
7977
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7978<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7979<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7980 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7981</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7982
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7983<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7984
7985<h5>Syntax:</h5>
7986<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7987 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
7988 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7989</pre>
7990
7991<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7992<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
7993 the optimizers to determine at compile time whether a) an operation (like
7994 memcpy) will overflow a buffer that corresponds to an object, or b) that a
7995 runtime check for overflow isn't necessary. An object in this context means
7996 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7997
7998<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7999<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8000 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8001 is a boolean 0 or 1. This argument determines whether you want the
8002 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]8003 1, variables are not allowed.</p>
8004
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8005<h5>Semantics:</h5>
8006<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8007 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8008 depending on the <tt>type</tt> argument, if the size cannot be determined at
8009 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8010
8011</div>
8012
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8013</div>
8014
8015</div>
8016
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8017<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8018<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8019<address>
8020 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8021 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8022 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8023 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]8024
8025 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8026 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8027 Last modified: $Date$
8028</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8029
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8030</body>
8031</html>