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gerrit-public.fairphone.software / toolchain / llvm-project / bbd8bd3257c412b9ec1afe6148ca95f548c818a0 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 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 Lattner6af02f32004-12-09 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 Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]34 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]46 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]47 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]48 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]49 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]50 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]51 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]52 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]53 </ol>
54 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]55 <li><a href="#typesystem">Type System</a>
56 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]57 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]58 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]59 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]60 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_floating">Floating Point Types</a></li>
62 <li><a href="#t_void">Void Type</a></li>
63 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]64 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]65 </ol>
66 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#t_derived">Derived Types</a>
68 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]69 <li><a href="#t_aggregate">Aggregate Types</a>
70 <ol>
71 <li><a href="#t_array">Array Type</a></li>
72 <li><a href="#t_struct">Structure Type</a></li>
73 <li><a href="#t_pstruct">Packed Structure Type</a></li>
74 <li><a href="#t_union">Union Type</a></li>
75 <li><a href="#t_vector">Vector Type</a></li>
76 </ol>
77 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#t_function">Function Type</a></li>
79 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]80 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]81 </ol>
82 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]83 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]86 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]87 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]88 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]89 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
91 <li><a href="#undefvalues">Undefined Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]92 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]94 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]95 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]96 <li><a href="#othervalues">Other Values</a>
97 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]98 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]99 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]102 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
103 <ol>
104 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]105 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
106 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]107 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
108 Global Variable</a></li>
109 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
110 Global Variable</a></li>
111 </ol>
112 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]113 <li><a href="#instref">Instruction Reference</a>
114 <ol>
115 <li><a href="#terminators">Terminator Instructions</a>
116 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]117 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
118 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]119 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]120 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]123 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 </ol>
125 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]126 <li><a href="#binaryops">Binary Operations</a>
127 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]129 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]134 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
135 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
136 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]137 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
138 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
139 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 </ol>
141 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]142 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
143 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]144 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
145 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
146 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]147 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]150 </ol>
151 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]152 <li><a href="#vectorops">Vector Operations</a>
153 <ol>
154 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
155 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
156 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]157 </ol>
158 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]159 <li><a href="#aggregateops">Aggregate Operations</a>
160 <ol>
161 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
162 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
163 </ol>
164 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]165 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]166 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]167 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]168 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
169 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
170 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]171 </ol>
172 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]173 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]174 <ol>
175 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
176 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
178 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
179 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]180 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
182 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
183 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]184 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
185 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]186 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]187 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]188 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]189 <li><a href="#otherops">Other Operations</a>
190 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]191 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
192 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]193 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]194 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]196 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]197 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]198 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]199 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]200 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]201 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]202 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
204 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]205 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
206 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
207 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]210 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
211 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
213 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
214 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]215 </ol>
216 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]217 <li><a href="#int_codegen">Code Generator Intrinsics</a>
218 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]219 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
220 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
221 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
222 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
223 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
224 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
225 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]226 </ol>
227 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]228 <li><a href="#int_libc">Standard C Library Intrinsics</a>
229 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]230 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
232 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]235 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]238 </ol>
239 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]240 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]241 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]242 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]243 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
244 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
245 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]246 </ol>
247 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]248 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
249 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]250 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
251 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
252 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
253 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
254 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]255 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]256 </ol>
257 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]258 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
259 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame^]260 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
261 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]262 </ol>
263 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]264 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]265 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]266 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]267 <ol>
268 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]269 </ol>
270 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]271 <li><a href="#int_atomics">Atomic intrinsics</a>
272 <ol>
273 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
274 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
275 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
276 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
277 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
278 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
279 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
280 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
281 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
282 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
283 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
284 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
285 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
286 </ol>
287 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]288 <li><a href="#int_memorymarkers">Memory Use Markers</a>
289 <ol>
290 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
291 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
292 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
293 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
294 </ol>
295 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]296 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]297 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]298 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]299 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]300 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]301 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]302 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]303 '<tt>llvm.trap</tt>' Intrinsic</a></li>
304 <li><a href="#int_stackprotector">
305 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]306 <li><a href="#int_objectsize">
307 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]308 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]309 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]310 </ol>
311 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]312</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]313
314<div class="doc_author">
315 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
316 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]317</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]318
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]319<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]320<div class="doc_section"> <a name="abstract">Abstract </a></div>
321<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]322
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]323<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]324
325<p>This document is a reference manual for the LLVM assembly language. LLVM is
326 a Static Single Assignment (SSA) based representation that provides type
327 safety, low-level operations, flexibility, and the capability of representing
328 'all' high-level languages cleanly. It is the common code representation
329 used throughout all phases of the LLVM compilation strategy.</p>
330
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]331</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]332
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]333<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]334<div class="doc_section"> <a name="introduction">Introduction</a> </div>
335<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]336
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]337<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]338
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]339<p>The LLVM code representation is designed to be used in three different forms:
340 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
341 for fast loading by a Just-In-Time compiler), and as a human readable
342 assembly language representation. This allows LLVM to provide a powerful
343 intermediate representation for efficient compiler transformations and
344 analysis, while providing a natural means to debug and visualize the
345 transformations. The three different forms of LLVM are all equivalent. This
346 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]348<p>The LLVM representation aims to be light-weight and low-level while being
349 expressive, typed, and extensible at the same time. It aims to be a
350 "universal IR" of sorts, by being at a low enough level that high-level ideas
351 may be cleanly mapped to it (similar to how microprocessors are "universal
352 IR's", allowing many source languages to be mapped to them). By providing
353 type information, LLVM can be used as the target of optimizations: for
354 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]355 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]356 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]357
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]358</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]359
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]360<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]361<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]362
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]363<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]364
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]365<p>It is important to note that this document describes 'well formed' LLVM
366 assembly language. There is a difference between what the parser accepts and
367 what is considered 'well formed'. For example, the following instruction is
368 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]370<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]371<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]372%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]373</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]374</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]376<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
377 LLVM infrastructure provides a verification pass that may be used to verify
378 that an LLVM module is well formed. This pass is automatically run by the
379 parser after parsing input assembly and by the optimizer before it outputs
380 bitcode. The violations pointed out by the verifier pass indicate bugs in
381 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]382
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]383</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]384
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]385<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]386
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]387<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]388<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]389<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]390
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]391<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]393<p>LLVM identifiers come in two basic types: global and local. Global
394 identifiers (functions, global variables) begin with the <tt>'@'</tt>
395 character. Local identifiers (register names, types) begin with
396 the <tt>'%'</tt> character. Additionally, there are three different formats
397 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]399<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]400 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]401 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
402 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
403 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
404 other characters in their names can be surrounded with quotes. Special
405 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
406 ASCII code for the character in hexadecimal. In this way, any character
407 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]408
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]409 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]410 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]411
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]412 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]413 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]414</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]415
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]416<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]417 don't need to worry about name clashes with reserved words, and the set of
418 reserved words may be expanded in the future without penalty. Additionally,
419 unnamed identifiers allow a compiler to quickly come up with a temporary
420 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]422<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]423 languages. There are keywords for different opcodes
424 ('<tt><a href="#i_add">add</a></tt>',
425 '<tt><a href="#i_bitcast">bitcast</a></tt>',
426 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
427 ('<tt><a href="#t_void">void</a></tt>',
428 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
429 reserved words cannot conflict with variable names, because none of them
430 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]431
432<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]433 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]434
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]435<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]437<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]439%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]441</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]443<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]445<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]447%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]449</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]451<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]452
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]453<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454<pre>
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]455%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
456%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]457%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]459</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]460
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
482<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
483<!-- *********************************************************************** -->
484
485<!-- ======================================================================= -->
486<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
487</div>
488
489<div class="doc_text">
490
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]491<p>LLVM programs are composed of "Module"s, each of which is a translation unit
492 of the input programs. Each module consists of functions, global variables,
493 and symbol table entries. Modules may be combined together with the LLVM
494 linker, which merges function (and global variable) definitions, resolves
495 forward declarations, and merges symbol table entries. Here is an example of
496 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]498<div class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]499<pre>
500<i>; Declare the string constant as a global constant.</i>
501<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
503<i>; External declaration of the puts function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]504<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>
508 <i>; Convert [13 x i8]* to i8 *...</i>
509 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]510
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>
512 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]513 <a href="#i_ret">ret</a> i32 0<br>}
514
515<i>; Named metadata</i>
516!1 = metadata !{i32 41}
517!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]518</pre>
519</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]521<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
536<div class="doc_subsection">
537 <a name="linkage">Linkage Types</a>
538</div>
539
540<div class="doc_text">
541
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]547 <dd>Global values with private linkage are only directly accessible by objects
548 in the current module. In particular, linking code into a module with an
549 private global value may cause the private to be renamed as necessary to
550 avoid collisions. Because the symbol is private to the module, all
551 references can be updated. This doesn't show up in any symbol table in the
552 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]555 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere7f064e2009-08-24 04:32:16 +0000[diff] [blame]556 removed by the linker after evaluation. Note that (unlike private
557 symbols) linker_private symbols are subject to coalescing by the linker:
558 weak symbols get merged and redefinitions are rejected. However, unlike
559 normal strong symbols, they are removed by the linker from the final
560 linked image (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]561
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]562 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]563 <dd>Similar to private, but the value shows as a local symbol
564 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
565 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]566
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]567 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]568 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]569 into the object file corresponding to the LLVM module. They exist to
570 allow inlining and other optimizations to take place given knowledge of
571 the definition of the global, which is known to be somewhere outside the
572 module. Globals with <tt>available_externally</tt> linkage are allowed to
573 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
574 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]575
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]577 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]578 the same name when linkage occurs. This can be used to implement
579 some forms of inline functions, templates, or other code which must be
580 generated in each translation unit that uses it, but where the body may
581 be overridden with a more definitive definition later. Unreferenced
582 <tt>linkonce</tt> globals are allowed to be discarded. Note that
583 <tt>linkonce</tt> linkage does not actually allow the optimizer to
584 inline the body of this function into callers because it doesn't know if
585 this definition of the function is the definitive definition within the
586 program or whether it will be overridden by a stronger definition.
587 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
588 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]589
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]591 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
592 <tt>linkonce</tt> linkage, except that unreferenced globals with
593 <tt>weak</tt> linkage may not be discarded. This is used for globals that
594 are declared "weak" in C source code.</dd>
595
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]596 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]597 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
598 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
599 global scope.
600 Symbols with "<tt>common</tt>" linkage are merged in the same way as
601 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]602 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]603 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]604 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
605 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]606
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]607
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]609 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]610 pointer to array type. When two global variables with appending linkage
611 are linked together, the two global arrays are appended together. This is
612 the LLVM, typesafe, equivalent of having the system linker append together
613 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]614
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]615 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]616 <dd>The semantics of this linkage follow the ELF object file model: the symbol
617 is weak until linked, if not linked, the symbol becomes null instead of
618 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]619
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]620 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
621 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]622 <dd>Some languages allow differing globals to be merged, such as two functions
623 with different semantics. Other languages, such as <tt>C++</tt>, ensure
624 that only equivalent globals are ever merged (the "one definition rule" -
625 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
626 and <tt>weak_odr</tt> linkage types to indicate that the global will only
627 be merged with equivalent globals. These linkage types are otherwise the
628 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]629
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]630 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]631 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]632 visible, meaning that it participates in linkage and can be used to
633 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]634</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]635
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]636<p>The next two types of linkage are targeted for Microsoft Windows platform
637 only. They are designed to support importing (exporting) symbols from (to)
638 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]639
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]640<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]641 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]642 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]643 or variable via a global pointer to a pointer that is set up by the DLL
644 exporting the symbol. On Microsoft Windows targets, the pointer name is
645 formed by combining <code>__imp_</code> and the function or variable
646 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]647
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]648 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]649 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]650 pointer to a pointer in a DLL, so that it can be referenced with the
651 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
652 name is formed by combining <code>__imp_</code> and the function or
653 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]654</dl>
655
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]656<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
657 another module defined a "<tt>.LC0</tt>" variable and was linked with this
658 one, one of the two would be renamed, preventing a collision. Since
659 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
660 declarations), they are accessible outside of the current module.</p>
661
662<p>It is illegal for a function <i>declaration</i> to have any linkage type
663 other than "externally visible", <tt>dllimport</tt>
664 or <tt>extern_weak</tt>.</p>
665
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]666<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]667 or <tt>weak_odr</tt> linkages.</p>
668
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]669</div>
670
671<!-- ======================================================================= -->
672<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]673 <a name="callingconv">Calling Conventions</a>
674</div>
675
676<div class="doc_text">
677
678<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]679 and <a href="#i_invoke">invokes</a> can all have an optional calling
680 convention specified for the call. The calling convention of any pair of
681 dynamic caller/callee must match, or the behavior of the program is
682 undefined. The following calling conventions are supported by LLVM, and more
683 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]684
685<dl>
686 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]687 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]688 specified) matches the target C calling conventions. This calling
689 convention supports varargs function calls and tolerates some mismatch in
690 the declared prototype and implemented declaration of the function (as
691 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]692
693 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]694 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]695 (e.g. by passing things in registers). This calling convention allows the
696 target to use whatever tricks it wants to produce fast code for the
697 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]698 (Application Binary Interface).
699 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]700 when this or the GHC convention is used.</a> This calling convention
701 does not support varargs and requires the prototype of all callees to
702 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]703
704 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]706 as possible under the assumption that the call is not commonly executed.
707 As such, these calls often preserve all registers so that the call does
708 not break any live ranges in the caller side. This calling convention
709 does not support varargs and requires the prototype of all callees to
710 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]711
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]712 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
713 <dd>This calling convention has been implemented specifically for use by the
714 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
715 It passes everything in registers, going to extremes to achieve this by
716 disabling callee save registers. This calling convention should not be
717 used lightly but only for specific situations such as an alternative to
718 the <em>register pinning</em> performance technique often used when
719 implementing functional programming languages.At the moment only X86
720 supports this convention and it has the following limitations:
721 <ul>
722 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
723 floating point types are supported.</li>
724 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
725 6 floating point parameters.</li>
726 </ul>
727 This calling convention supports
728 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
729 requires both the caller and callee are using it.
730 </dd>
731
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]732 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]733 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]734 target-specific calling conventions to be used. Target specific calling
735 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]736</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]737
738<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]739 support Pascal conventions or any other well-known target-independent
740 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]741
742</div>
743
744<!-- ======================================================================= -->
745<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]746 <a name="visibility">Visibility Styles</a>
747</div>
748
749<div class="doc_text">
750
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]751<p>All Global Variables and Functions have one of the following visibility
752 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]753
754<dl>
755 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]756 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]757 that the declaration is visible to other modules and, in shared libraries,
758 means that the declared entity may be overridden. On Darwin, default
759 visibility means that the declaration is visible to other modules. Default
760 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]761
762 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]764 object if they are in the same shared object. Usually, hidden visibility
765 indicates that the symbol will not be placed into the dynamic symbol
766 table, so no other module (executable or shared library) can reference it
767 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]768
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]769 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]770 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]771 the dynamic symbol table, but that references within the defining module
772 will bind to the local symbol. That is, the symbol cannot be overridden by
773 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]774</dl>
775
776</div>
777
778<!-- ======================================================================= -->
779<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]780 <a name="namedtypes">Named Types</a>
781</div>
782
783<div class="doc_text">
784
785<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]786 it easier to read the IR and make the IR more condensed (particularly when
787 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]788
789<div class="doc_code">
790<pre>
791%mytype = type { %mytype*, i32 }
792</pre>
793</div>
794
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]795<p>You may give a name to any <a href="#typesystem">type</a> except
796 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
797 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]798
799<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]800 and that you can therefore specify multiple names for the same type. This
801 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
802 uses structural typing, the name is not part of the type. When printing out
803 LLVM IR, the printer will pick <em>one name</em> to render all types of a
804 particular shape. This means that if you have code where two different
805 source types end up having the same LLVM type, that the dumper will sometimes
806 print the "wrong" or unexpected type. This is an important design point and
807 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]808
809</div>
810
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]811<!-- ======================================================================= -->
812<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]813 <a name="globalvars">Global Variables</a>
814</div>
815
816<div class="doc_text">
817
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]818<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]819 instead of run-time. Global variables may optionally be initialized, may
820 have an explicit section to be placed in, and may have an optional explicit
821 alignment specified. A variable may be defined as "thread_local", which
822 means that it will not be shared by threads (each thread will have a
823 separated copy of the variable). A variable may be defined as a global
824 "constant," which indicates that the contents of the variable
825 will <b>never</b> be modified (enabling better optimization, allowing the
826 global data to be placed in the read-only section of an executable, etc).
827 Note that variables that need runtime initialization cannot be marked
828 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]829
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]830<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
831 constant, even if the final definition of the global is not. This capability
832 can be used to enable slightly better optimization of the program, but
833 requires the language definition to guarantee that optimizations based on the
834 'constantness' are valid for the translation units that do not include the
835 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]836
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]837<p>As SSA values, global variables define pointer values that are in scope
838 (i.e. they dominate) all basic blocks in the program. Global variables
839 always define a pointer to their "content" type because they describe a
840 region of memory, and all memory objects in LLVM are accessed through
841 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]842
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]843<p>A global variable may be declared to reside in a target-specific numbered
844 address space. For targets that support them, address spaces may affect how
845 optimizations are performed and/or what target instructions are used to
846 access the variable. The default address space is zero. The address space
847 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]848
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]849<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]850 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]851
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]852<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]853 the alignment is set to zero, the alignment of the global is set by the
854 target to whatever it feels convenient. If an explicit alignment is
855 specified, the global is forced to have at least that much alignment. All
856 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]857
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]858<p>For example, the following defines a global in a numbered address space with
859 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]860
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]861<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]862<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]863@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]864</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]865</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]866
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]867</div>
868
869
870<!-- ======================================================================= -->
871<div class="doc_subsection">
872 <a name="functionstructure">Functions</a>
873</div>
874
875<div class="doc_text">
876
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]877<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]878 optional <a href="#linkage">linkage type</a>, an optional
879 <a href="#visibility">visibility style</a>, an optional
880 <a href="#callingconv">calling convention</a>, a return type, an optional
881 <a href="#paramattrs">parameter attribute</a> for the return type, a function
882 name, a (possibly empty) argument list (each with optional
883 <a href="#paramattrs">parameter attributes</a>), optional
884 <a href="#fnattrs">function attributes</a>, an optional section, an optional
885 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
886 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]887
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]888<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
889 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]890 <a href="#visibility">visibility style</a>, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]891 <a href="#callingconv">calling convention</a>, a return type, an optional
892 <a href="#paramattrs">parameter attribute</a> for the return type, a function
893 name, a possibly empty list of arguments, an optional alignment, and an
894 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]895
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]896<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]897 (Control Flow Graph) for the function. Each basic block may optionally start
898 with a label (giving the basic block a symbol table entry), contains a list
899 of instructions, and ends with a <a href="#terminators">terminator</a>
900 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]901
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]902<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]903 executed on entrance to the function, and it is not allowed to have
904 predecessor basic blocks (i.e. there can not be any branches to the entry
905 block of a function). Because the block can have no predecessors, it also
906 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]907
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]908<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]909 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]910
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]911<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]912 the alignment is set to zero, the alignment of the function is set by the
913 target to whatever it feels convenient. If an explicit alignment is
914 specified, the function is forced to have at least that much alignment. All
915 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]916
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]917<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]918<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]920define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]921 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
922 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
923 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
924 [<a href="#gc">gc</a>] { ... }
925</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]926</div>
927
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]928</div>
929
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]930<!-- ======================================================================= -->
931<div class="doc_subsection">
932 <a name="aliasstructure">Aliases</a>
933</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]934
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]935<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]936
937<p>Aliases act as "second name" for the aliasee value (which can be either
938 function, global variable, another alias or bitcast of global value). Aliases
939 may have an optional <a href="#linkage">linkage type</a>, and an
940 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]941
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]943<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]944<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]945@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]946</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]947</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]948
949</div>
950
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]951<!-- ======================================================================= -->
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]952<div class="doc_subsection">
953 <a name="namedmetadatastructure">Named Metadata</a>
954</div>
955
956<div class="doc_text">
957
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]958<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
959 nodes</a> (but not metadata strings) and null are the only valid operands for
960 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]961
962<h5>Syntax:</h5>
963<div class="doc_code">
964<pre>
965!1 = metadata !{metadata !"one"}
966!name = !{null, !1}
967</pre>
968</div>
969
970</div>
971
972<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]973<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]974
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]975<div class="doc_text">
976
977<p>The return type and each parameter of a function type may have a set of
978 <i>parameter attributes</i> associated with them. Parameter attributes are
979 used to communicate additional information about the result or parameters of
980 a function. Parameter attributes are considered to be part of the function,
981 not of the function type, so functions with different parameter attributes
982 can have the same function type.</p>
983
984<p>Parameter attributes are simple keywords that follow the type specified. If
985 multiple parameter attributes are needed, they are space separated. For
986 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]987
988<div class="doc_code">
989<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]990declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]991declare i32 @atoi(i8 zeroext)
992declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]993</pre>
994</div>
995
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]996<p>Note that any attributes for the function result (<tt>nounwind</tt>,
997 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]998
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]999<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1000
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1001<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1002 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1003 <dd>This indicates to the code generator that the parameter or return value
1004 should be zero-extended to a 32-bit value by the caller (for a parameter)
1005 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1006
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1007 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1008 <dd>This indicates to the code generator that the parameter or return value
1009 should be sign-extended to a 32-bit value by the caller (for a parameter)
1010 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1011
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1012 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1013 <dd>This indicates that this parameter or return value should be treated in a
1014 special target-dependent fashion during while emitting code for a function
1015 call or return (usually, by putting it in a register as opposed to memory,
1016 though some targets use it to distinguish between two different kinds of
1017 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1018
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1019 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1020 <dd>This indicates that the pointer parameter should really be passed by value
1021 to the function. The attribute implies that a hidden copy of the pointee
1022 is made between the caller and the callee, so the callee is unable to
1023 modify the value in the callee. This attribute is only valid on LLVM
1024 pointer arguments. It is generally used to pass structs and arrays by
1025 value, but is also valid on pointers to scalars. The copy is considered
1026 to belong to the caller not the callee (for example,
1027 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1028 <tt>byval</tt> parameters). This is not a valid attribute for return
1029 values. The byval attribute also supports specifying an alignment with
1030 the align attribute. This has a target-specific effect on the code
1031 generator that usually indicates a desired alignment for the synthesized
1032 stack slot.</dd>
1033
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1034 <dt><tt><b>sret</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1035 <dd>This indicates that the pointer parameter specifies the address of a
1036 structure that is the return value of the function in the source program.
1037 This pointer must be guaranteed by the caller to be valid: loads and
1038 stores to the structure may be assumed by the callee to not to trap. This
1039 may only be applied to the first parameter. This is not a valid attribute
1040 for return values. </dd>
1041
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1042 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This indicates that the pointer does not alias any global or any other
1044 parameter. The caller is responsible for ensuring that this is the
1045 case. On a function return value, <tt>noalias</tt> additionally indicates
1046 that the pointer does not alias any other pointers visible to the
1047 caller. For further details, please see the discussion of the NoAlias
1048 response in
1049 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1050 analysis</a>.</dd>
1051
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1052 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1053 <dd>This indicates that the callee does not make any copies of the pointer
1054 that outlive the callee itself. This is not a valid attribute for return
1055 values.</dd>
1056
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1057 <dt><tt><b>nest</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1058 <dd>This indicates that the pointer parameter can be excised using the
1059 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1060 attribute for return values.</dd>
1061</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1062
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1063</div>
1064
1065<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1066<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1067 <a name="gc">Garbage Collector Names</a>
1068</div>
1069
1070<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1071
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1072<p>Each function may specify a garbage collector name, which is simply a
1073 string:</p>
1074
1075<div class="doc_code">
1076<pre>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1077define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1078</pre>
1079</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1080
1081<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1082 collector which will cause the compiler to alter its output in order to
1083 support the named garbage collection algorithm.</p>
1084
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1085</div>
1086
1087<!-- ======================================================================= -->
1088<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1089 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1090</div>
1091
1092<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1093
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1094<p>Function attributes are set to communicate additional information about a
1095 function. Function attributes are considered to be part of the function, not
1096 of the function type, so functions with different parameter attributes can
1097 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1098
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099<p>Function attributes are simple keywords that follow the type specified. If
1100 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1101
1102<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1103<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1104define void @f() noinline { ... }
1105define void @f() alwaysinline { ... }
1106define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1107define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1108</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1109</div>
1110
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1111<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1112 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1113 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1114 the backend should forcibly align the stack pointer. Specify the
1115 desired alignment, which must be a power of two, in parentheses.
1116
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1117 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118 <dd>This attribute indicates that the inliner should attempt to inline this
1119 function into callers whenever possible, ignoring any active inlining size
1120 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1121
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1122 <dt><tt><b>inlinehint</b></tt></dt>
1123 <dd>This attribute indicates that the source code contained a hint that inlining
1124 this function is desirable (such as the "inline" keyword in C/C++). It
1125 is just a hint; it imposes no requirements on the inliner.</dd>
1126
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1127 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1128 <dd>This attribute indicates that the inliner should never inline this
1129 function in any situation. This attribute may not be used together with
1130 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1131
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1132 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1133 <dd>This attribute suggests that optimization passes and code generator passes
1134 make choices that keep the code size of this function low, and otherwise
1135 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1137 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1138 <dd>This function attribute indicates that the function never returns
1139 normally. This produces undefined behavior at runtime if the function
1140 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1141
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1142 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1143 <dd>This function attribute indicates that the function never returns with an
1144 unwind or exceptional control flow. If the function does unwind, its
1145 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1146
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1147 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1148 <dd>This attribute indicates that the function computes its result (or decides
1149 to unwind an exception) based strictly on its arguments, without
1150 dereferencing any pointer arguments or otherwise accessing any mutable
1151 state (e.g. memory, control registers, etc) visible to caller functions.
1152 It does not write through any pointer arguments
1153 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1154 changes any state visible to callers. This means that it cannot unwind
1155 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1156 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1157
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1158 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1159 <dd>This attribute indicates that the function does not write through any
1160 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1161 arguments) or otherwise modify any state (e.g. memory, control registers,
1162 etc) visible to caller functions. It may dereference pointer arguments
1163 and read state that may be set in the caller. A readonly function always
1164 returns the same value (or unwinds an exception identically) when called
1165 with the same set of arguments and global state. It cannot unwind an
1166 exception by calling the <tt>C++</tt> exception throwing methods, but may
1167 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1168
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1169 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1170 <dd>This attribute indicates that the function should emit a stack smashing
1171 protector. It is in the form of a "canary"&mdash;a random value placed on
1172 the stack before the local variables that's checked upon return from the
1173 function to see if it has been overwritten. A heuristic is used to
1174 determine if a function needs stack protectors or not.<br>
1175<br>
1176 If a function that has an <tt>ssp</tt> attribute is inlined into a
1177 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1178 function will have an <tt>ssp</tt> attribute.</dd>
1179
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1180 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1181 <dd>This attribute indicates that the function should <em>always</em> emit a
1182 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1183 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1184<br>
1185 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1186 function that doesn't have an <tt>sspreq</tt> attribute or which has
1187 an <tt>ssp</tt> attribute, then the resulting function will have
1188 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1189
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1190 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1191 <dd>This attribute indicates that the code generator should not use a red
1192 zone, even if the target-specific ABI normally permits it.</dd>
1193
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1194 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1195 <dd>This attributes disables implicit floating point instructions.</dd>
1196
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>naked</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This attribute disables prologue / epilogue emission for the function.
1199 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1200</dl>
1201
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1202</div>
1203
1204<!-- ======================================================================= -->
1205<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1206 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1207</div>
1208
1209<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1210
1211<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1212 the GCC "file scope inline asm" blocks. These blocks are internally
1213 concatenated by LLVM and treated as a single unit, but may be separated in
1214 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1215
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1216<div class="doc_code">
1217<pre>
1218module asm "inline asm code goes here"
1219module asm "more can go here"
1220</pre>
1221</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1222
1223<p>The strings can contain any character by escaping non-printable characters.
1224 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1225 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1226
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1227<p>The inline asm code is simply printed to the machine code .s file when
1228 assembly code is generated.</p>
1229
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1230</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1231
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1232<!-- ======================================================================= -->
1233<div class="doc_subsection">
1234 <a name="datalayout">Data Layout</a>
1235</div>
1236
1237<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1238
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1239<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1240 data is to be laid out in memory. The syntax for the data layout is
1241 simply:</p>
1242
1243<div class="doc_code">
1244<pre>
1245target datalayout = "<i>layout specification</i>"
1246</pre>
1247</div>
1248
1249<p>The <i>layout specification</i> consists of a list of specifications
1250 separated by the minus sign character ('-'). Each specification starts with
1251 a letter and may include other information after the letter to define some
1252 aspect of the data layout. The specifications accepted are as follows:</p>
1253
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1254<dl>
1255 <dt><tt>E</tt></dt>
1256 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1257 bits with the most significance have the lowest address location.</dd>
1258
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1259 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1260 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1261 the bits with the least significance have the lowest address
1262 location.</dd>
1263
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1264 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1265 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1266 <i>preferred</i> alignments. All sizes are in bits. Specifying
1267 the <i>pref</i> alignment is optional. If omitted, the
1268 preceding <tt>:</tt> should be omitted too.</dd>
1269
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1270 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1271 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1272 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1273
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1274 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1275 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1276 <i>size</i>.</dd>
1277
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1278 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1279 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1280 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1281 (double).</dd>
1282
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1283 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1284 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1285 <i>size</i>.</dd>
1286
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1287 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1288 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1289 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1290
1291 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1292 <dd>This specifies a set of native integer widths for the target CPU
1293 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1294 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1295 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1296 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1297</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1298
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1299<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1300 default set of specifications which are then (possibly) overriden by the
1301 specifications in the <tt>datalayout</tt> keyword. The default specifications
1302 are given in this list:</p>
1303
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1304<ul>
1305 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1306 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1307 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1308 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1309 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1310 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1311 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1312 alignment of 64-bits</li>
1313 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1314 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1315 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1316 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1317 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1318 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1319</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1320
1321<p>When LLVM is determining the alignment for a given type, it uses the
1322 following rules:</p>
1323
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1324<ol>
1325 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1326 specification is used.</li>
1327
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1328 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1329 smallest integer type that is larger than the bitwidth of the sought type
1330 is used. If none of the specifications are larger than the bitwidth then
1331 the the largest integer type is used. For example, given the default
1332 specifications above, the i7 type will use the alignment of i8 (next
1333 largest) while both i65 and i256 will use the alignment of i64 (largest
1334 specified).</li>
1335
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1336 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1337 largest vector type that is smaller than the sought vector type will be
1338 used as a fall back. This happens because &lt;128 x double&gt; can be
1339 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1340</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1341
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1342</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1343
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1344<!-- ======================================================================= -->
1345<div class="doc_subsection">
1346 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1347</div>
1348
1349<div class="doc_text">
1350
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1351<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1352with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1353is undefined. Pointer values are associated with address ranges
1354according to the following rules:</p>
1355
1356<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1357 <li>A pointer value formed from a
1358 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1359 is associated with the addresses associated with the first operand
1360 of the <tt>getelementptr</tt>.</li>
1361 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1362 range of the variable's storage.</li>
1363 <li>The result value of an allocation instruction is associated with
1364 the address range of the allocated storage.</li>
1365 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1366 no address.</li>
1367 <li>A pointer value formed by an
1368 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1369 address ranges of all pointer values that contribute (directly or
1370 indirectly) to the computation of the pointer's value.</li>
1371 <li>The result value of a
1372 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1373 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1374 <li>An integer constant other than zero or a pointer value returned
1375 from a function not defined within LLVM may be associated with address
1376 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1377 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1378 allocated by mechanisms provided by LLVM.</li>
1379 </ul>
1380
1381<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1382<tt><a href="#i_load">load</a></tt> merely indicates the size and
1383alignment of the memory from which to load, as well as the
1384interpretation of the value. The first operand of a
1385<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1386and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1387
1388<p>Consequently, type-based alias analysis, aka TBAA, aka
1389<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1390LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1391additional information which specialized optimization passes may use
1392to implement type-based alias analysis.</p>
1393
1394</div>
1395
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1396<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1397<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1398<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1399
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1400<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1401
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1402<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1403 intermediate representation. Being typed enables a number of optimizations
1404 to be performed on the intermediate representation directly, without having
1405 to do extra analyses on the side before the transformation. A strong type
1406 system makes it easier to read the generated code and enables novel analyses
1407 and transformations that are not feasible to perform on normal three address
1408 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1409
1410</div>
1411
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1412<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1413<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1414Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1415
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1416<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1417
1418<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1419
1420<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1421 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1422 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1423 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1424 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1425 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1426 </tr>
1427 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1428 <td><a href="#t_floating">floating point</a></td>
1429 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1430 </tr>
1431 <tr>
1432 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1433 <td><a href="#t_integer">integer</a>,
1434 <a href="#t_floating">floating point</a>,
1435 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1436 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1437 <a href="#t_struct">structure</a>,
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1438 <a href="#t_union">union</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1439 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1440 <a href="#t_label">label</a>,
1441 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1442 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1443 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1444 <tr>
1445 <td><a href="#t_primitive">primitive</a></td>
1446 <td><a href="#t_label">label</a>,
1447 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1448 <a href="#t_floating">floating point</a>,
1449 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1450 </tr>
1451 <tr>
1452 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1453 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1454 <a href="#t_function">function</a>,
1455 <a href="#t_pointer">pointer</a>,
1456 <a href="#t_struct">structure</a>,
1457 <a href="#t_pstruct">packed structure</a>,
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1458 <a href="#t_union">union</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1459 <a href="#t_vector">vector</a>,
1460 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1461 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1462 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1463 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1464</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1465
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1466<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1467 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1468 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1469
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1470</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1471
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1472<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1473<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1474
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1475<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1476
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1477<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1478 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1479
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1480</div>
1481
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1482<!-- _______________________________________________________________________ -->
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1483<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1484
1485<div class="doc_text">
1486
1487<h5>Overview:</h5>
1488<p>The integer type is a very simple type that simply specifies an arbitrary
1489 bit width for the integer type desired. Any bit width from 1 bit to
1490 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1491
1492<h5>Syntax:</h5>
1493<pre>
1494 iN
1495</pre>
1496
1497<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1498 value.</p>
1499
1500<h5>Examples:</h5>
1501<table class="layout">
1502 <tr class="layout">
1503 <td class="left"><tt>i1</tt></td>
1504 <td class="left">a single-bit integer.</td>
1505 </tr>
1506 <tr class="layout">
1507 <td class="left"><tt>i32</tt></td>
1508 <td class="left">a 32-bit integer.</td>
1509 </tr>
1510 <tr class="layout">
1511 <td class="left"><tt>i1942652</tt></td>
1512 <td class="left">a really big integer of over 1 million bits.</td>
1513 </tr>
1514</table>
1515
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1516</div>
1517
1518<!-- _______________________________________________________________________ -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1519<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1520
1521<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1522
1523<table>
1524 <tbody>
1525 <tr><th>Type</th><th>Description</th></tr>
1526 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1527 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1528 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1529 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1530 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1531 </tbody>
1532</table>
1533
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1534</div>
1535
1536<!-- _______________________________________________________________________ -->
1537<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1538
1539<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1540
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1541<h5>Overview:</h5>
1542<p>The void type does not represent any value and has no size.</p>
1543
1544<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1545<pre>
1546 void
1547</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1548
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1549</div>
1550
1551<!-- _______________________________________________________________________ -->
1552<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1553
1554<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1555
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1556<h5>Overview:</h5>
1557<p>The label type represents code labels.</p>
1558
1559<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1560<pre>
1561 label
1562</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1563
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1564</div>
1565
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1566<!-- _______________________________________________________________________ -->
1567<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1568
1569<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1570
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1571<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1572<p>The metadata type represents embedded metadata. No derived types may be
1573 created from metadata except for <a href="#t_function">function</a>
1574 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1575
1576<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1577<pre>
1578 metadata
1579</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1580
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1581</div>
1582
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1583
1584<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1585<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1586
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1587<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1588
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1589<p>The real power in LLVM comes from the derived types in the system. This is
1590 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1591 useful types. Each of these types contain one or more element types which
1592 may be a primitive type, or another derived type. For example, it is
1593 possible to have a two dimensional array, using an array as the element type
1594 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1595
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1596
1597</div>
1598
1599<!-- _______________________________________________________________________ -->
1600<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1601
1602<div class="doc_text">
1603
1604<p>Aggregate Types are a subset of derived types that can contain multiple
1605 member types. <a href="#t_array">Arrays</a>,
1606 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1607 <a href="#t_union">unions</a> are aggregate types.</p>
1608
1609</div>
1610
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1611</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1612
1613<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1614<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1615
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1616<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1617
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1618<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1619<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1620 sequentially in memory. The array type requires a size (number of elements)
1621 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1622
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1623<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1624<pre>
1625 [&lt;# elements&gt; x &lt;elementtype&gt;]
1626</pre>
1627
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1628<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1629 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1630
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1631<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1632<table class="layout">
1633 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1634 <td class="left"><tt>[40 x i32]</tt></td>
1635 <td class="left">Array of 40 32-bit integer values.</td>
1636 </tr>
1637 <tr class="layout">
1638 <td class="left"><tt>[41 x i32]</tt></td>
1639 <td class="left">Array of 41 32-bit integer values.</td>
1640 </tr>
1641 <tr class="layout">
1642 <td class="left"><tt>[4 x i8]</tt></td>
1643 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1644 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1645</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1646<p>Here are some examples of multidimensional arrays:</p>
1647<table class="layout">
1648 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1649 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1650 <td class="left">3x4 array of 32-bit integer values.</td>
1651 </tr>
1652 <tr class="layout">
1653 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1654 <td class="left">12x10 array of single precision floating point values.</td>
1655 </tr>
1656 <tr class="layout">
1657 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1658 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1659 </tr>
1660</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1661
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1662<p>There is no restriction on indexing beyond the end of the array implied by
1663 a static type (though there are restrictions on indexing beyond the bounds
1664 of an allocated object in some cases). This means that single-dimension
1665 'variable sized array' addressing can be implemented in LLVM with a zero
1666 length array type. An implementation of 'pascal style arrays' in LLVM could
1667 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1668
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1669</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1670
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1671<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1672<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1673
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1674<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1675
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1676<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1677<p>The function type can be thought of as a function signature. It consists of
1678 a return type and a list of formal parameter types. The return type of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1679 function type is a scalar type, a void type, a struct type, or a union
1680 type. If the return type is a struct type then all struct elements must be
1681 of first class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1682
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1683<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1684<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1685 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1686</pre>
1687
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1688<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1689 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1690 which indicates that the function takes a variable number of arguments.
1691 Variable argument functions can access their arguments with
1692 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1693 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1694 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1696<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1697<table class="layout">
1698 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1699 <td class="left"><tt>i32 (i32)</tt></td>
1700 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1701 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1702 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1703 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1704 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1705 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1706 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1707 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1708 </td>
1709 </tr><tr class="layout">
1710 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1711 <td class="left">A vararg function that takes at least one
1712 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1713 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1714 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1715 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1716 </tr><tr class="layout">
1717 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1718 <td class="left">A function taking an <tt>i32</tt>, returning a
1719 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1720 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1721 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1722</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1723
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1724</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1725
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1726<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1727<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1728
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1729<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1730
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1731<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1732<p>The structure type is used to represent a collection of data members together
1733 in memory. The packing of the field types is defined to match the ABI of the
1734 underlying processor. The elements of a structure may be any type that has a
1735 size.</p>
1736
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1737<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1738 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1739 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1740 Structures in registers are accessed using the
1741 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1742 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1743<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1744<pre>
1745 { &lt;type list&gt; }
1746</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1747
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1748<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1749<table class="layout">
1750 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1751 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1752 <td class="left">A triple of three <tt>i32</tt> values</td>
1753 </tr><tr class="layout">
1754 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1755 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1756 second element is a <a href="#t_pointer">pointer</a> to a
1757 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1758 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1759 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1760</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1761
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1762</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1763
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1764<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1765<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1766</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1767
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1768<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1769
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1770<h5>Overview:</h5>
1771<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1772 together in memory. There is no padding between fields. Further, the
1773 alignment of a packed structure is 1 byte. The elements of a packed
1774 structure may be any type that has a size.</p>
1775
1776<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1777 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1778 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1779
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1780<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1781<pre>
1782 &lt; { &lt;type list&gt; } &gt;
1783</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1784
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1785<h5>Examples:</h5>
1786<table class="layout">
1787 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1788 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1789 <td class="left">A triple of three <tt>i32</tt> values</td>
1790 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1791 <td class="left">
1792<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1793 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1794 second element is a <a href="#t_pointer">pointer</a> to a
1795 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1796 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1797 </tr>
1798</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1799
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1800</div>
1801
1802<!-- _______________________________________________________________________ -->
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1803<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1804
1805<div class="doc_text">
1806
1807<h5>Overview:</h5>
1808<p>A union type describes an object with size and alignment suitable for
1809 an object of any one of a given set of types (also known as an "untagged"
1810 union). It is similar in concept and usage to a
1811 <a href="#t_struct">struct</a>, except that all members of the union
1812 have an offset of zero. The elements of a union may be any type that has a
1813 size. Unions must have at least one member - empty unions are not allowed.
1814 </p>
1815
1816<p>The size of the union as a whole will be the size of its largest member,
1817 and the alignment requirements of the union as a whole will be the largest
1818 alignment requirement of any member.</p>
1819
Dan Gohman1ad14992010-02-25 16:51:31 +0000[diff] [blame]1820<p>Union members are accessed using '<tt><a href="#i_load">load</a></tt> and
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1821 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1822 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1823 Since all members are at offset zero, the getelementptr instruction does
1824 not affect the address, only the type of the resulting pointer.</p>
1825
1826<h5>Syntax:</h5>
1827<pre>
1828 union { &lt;type list&gt; }
1829</pre>
1830
1831<h5>Examples:</h5>
1832<table class="layout">
1833 <tr class="layout">
1834 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1835 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1836 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1837 </tr><tr class="layout">
1838 <td class="left">
1839 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1840 <td class="left">A union, where the first element is a <tt>float</tt> and the
1841 second element is a <a href="#t_pointer">pointer</a> to a
1842 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1843 an <tt>i32</tt>.</td>
1844 </tr>
1845</table>
1846
1847</div>
1848
1849<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1850<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1851
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1852<div class="doc_text">
1853
1854<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1855<p>The pointer type is used to specify memory locations.
1856 Pointers are commonly used to reference objects in memory.</p>
1857
1858<p>Pointer types may have an optional address space attribute defining the
1859 numbered address space where the pointed-to object resides. The default
1860 address space is number zero. The semantics of non-zero address
1861 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1862
1863<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1864 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1865
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1866<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1867<pre>
1868 &lt;type&gt; *
1869</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1870
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1871<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1872<table class="layout">
1873 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1874 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1875 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1876 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1877 </tr>
1878 <tr class="layout">
1879 <td class="left"><tt>i32 (i32 *) *</tt></td>
1880 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1881 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1882 <tt>i32</tt>.</td>
1883 </tr>
1884 <tr class="layout">
1885 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1886 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1887 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1888 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1889</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1890
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1891</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1892
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1893<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1894<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1895
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1896<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1897
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1898<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1899<p>A vector type is a simple derived type that represents a vector of elements.
1900 Vector types are used when multiple primitive data are operated in parallel
1901 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1902 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1903 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1904
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1905<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1906<pre>
1907 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1908</pre>
1909
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1910<p>The number of elements is a constant integer value; elementtype may be any
1911 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1912
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1913<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1914<table class="layout">
1915 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1916 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1917 <td class="left">Vector of 4 32-bit integer values.</td>
1918 </tr>
1919 <tr class="layout">
1920 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1921 <td class="left">Vector of 8 32-bit floating-point values.</td>
1922 </tr>
1923 <tr class="layout">
1924 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1925 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1926 </tr>
1927</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1928
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1929</div>
1930
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1931<!-- _______________________________________________________________________ -->
1932<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1933<div class="doc_text">
1934
1935<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1936<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1937 corresponds (for example) to the C notion of a forward declared structure
1938 type. In LLVM, opaque types can eventually be resolved to any type (not just
1939 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1940
1941<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1942<pre>
1943 opaque
1944</pre>
1945
1946<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1947<table class="layout">
1948 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1949 <td class="left"><tt>opaque</tt></td>
1950 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1951 </tr>
1952</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1953
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1954</div>
1955
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1956<!-- ======================================================================= -->
1957<div class="doc_subsection">
1958 <a name="t_uprefs">Type Up-references</a>
1959</div>
1960
1961<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1962
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1963<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1964<p>An "up reference" allows you to refer to a lexically enclosing type without
1965 requiring it to have a name. For instance, a structure declaration may
1966 contain a pointer to any of the types it is lexically a member of. Example
1967 of up references (with their equivalent as named type declarations)
1968 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1969
1970<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1971 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1972 { \2 }* %y = type { %y }*
1973 \1* %z = type %z*
1974</pre>
1975
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1976<p>An up reference is needed by the asmprinter for printing out cyclic types
1977 when there is no declared name for a type in the cycle. Because the
1978 asmprinter does not want to print out an infinite type string, it needs a
1979 syntax to handle recursive types that have no names (all names are optional
1980 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1981
1982<h5>Syntax:</h5>
1983<pre>
1984 \&lt;level&gt;
1985</pre>
1986
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1987<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1988
1989<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1990<table class="layout">
1991 <tr class="layout">
1992 <td class="left"><tt>\1*</tt></td>
1993 <td class="left">Self-referential pointer.</td>
1994 </tr>
1995 <tr class="layout">
1996 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1997 <td class="left">Recursive structure where the upref refers to the out-most
1998 structure.</td>
1999 </tr>
2000</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2001
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2002</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2003
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2004<!-- *********************************************************************** -->
2005<div class="doc_section"> <a name="constants">Constants</a> </div>
2006<!-- *********************************************************************** -->
2007
2008<div class="doc_text">
2009
2010<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2011 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2012
2013</div>
2014
2015<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]2016<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2017
2018<div class="doc_text">
2019
2020<dl>
2021 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2022 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2023 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2024
2025 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2026 <dd>Standard integers (such as '4') are constants of
2027 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2028 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2029
2030 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2031 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2032 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2033 notation (see below). The assembler requires the exact decimal value of a
2034 floating-point constant. For example, the assembler accepts 1.25 but
2035 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2036 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2037
2038 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2039 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2040 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2041</dl>
2042
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2043<p>The one non-intuitive notation for constants is the hexadecimal form of
2044 floating point constants. For example, the form '<tt>double
2045 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2046 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2047 constants are required (and the only time that they are generated by the
2048 disassembler) is when a floating point constant must be emitted but it cannot
2049 be represented as a decimal floating point number in a reasonable number of
2050 digits. For example, NaN's, infinities, and other special values are
2051 represented in their IEEE hexadecimal format so that assembly and disassembly
2052 do not cause any bits to change in the constants.</p>
2053
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2054<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2055 represented using the 16-digit form shown above (which matches the IEEE754
2056 representation for double); float values must, however, be exactly
2057 representable as IEE754 single precision. Hexadecimal format is always used
2058 for long double, and there are three forms of long double. The 80-bit format
2059 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2060 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2061 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2062 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2063 currently supported target uses this format. Long doubles will only work if
2064 they match the long double format on your target. All hexadecimal formats
2065 are big-endian (sign bit at the left).</p>
2066
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2067</div>
2068
2069<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2070<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2071<a name="aggregateconstants"></a> <!-- old anchor -->
2072<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2073</div>
2074
2075<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2076
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2077<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2078 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2079
2080<dl>
2081 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2082 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2083 type definitions (a comma separated list of elements, surrounded by braces
2084 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2085 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2086 Structure constants must have <a href="#t_struct">structure type</a>, and
2087 the number and types of elements must match those specified by the
2088 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2089
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2090 <dt><b>Union constants</b></dt>
2091 <dd>Union constants are represented with notation similar to a structure with
2092 a single element - that is, a single typed element surrounded
2093 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2094 <a href="#t_union">union type</a> can be initialized with a single-element
2095 struct as long as the type of the struct element matches the type of
2096 one of the union members.</dd>
2097
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2098 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2099 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2100 definitions (a comma separated list of elements, surrounded by square
2101 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2102 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2103 the number and types of elements must match those specified by the
2104 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2105
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2106 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2107 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2108 definitions (a comma separated list of elements, surrounded by
2109 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2110 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2111 have <a href="#t_vector">vector type</a>, and the number and types of
2112 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2113
2114 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2115 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2116 value to zero of <em>any</em> type, including scalar and
2117 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2118 This is often used to avoid having to print large zero initializers
2119 (e.g. for large arrays) and is always exactly equivalent to using explicit
2120 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2121
2122 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2123 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2124 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2125 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2126 be interpreted as part of the instruction stream, metadata is a place to
2127 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2128</dl>
2129
2130</div>
2131
2132<!-- ======================================================================= -->
2133<div class="doc_subsection">
2134 <a name="globalconstants">Global Variable and Function Addresses</a>
2135</div>
2136
2137<div class="doc_text">
2138
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2139<p>The addresses of <a href="#globalvars">global variables</a>
2140 and <a href="#functionstructure">functions</a> are always implicitly valid
2141 (link-time) constants. These constants are explicitly referenced when
2142 the <a href="#identifiers">identifier for the global</a> is used and always
2143 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2144 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2145
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2146<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2147<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2148@X = global i32 17
2149@Y = global i32 42
2150@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2151</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2152</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2153
2154</div>
2155
2156<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2157<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2158<div class="doc_text">
2159
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2160<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2161 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2162 Undefined values may be of any type (other than label or void) and be used
2163 anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2164
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2165<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2166 program is well defined no matter what value is used. This gives the
2167 compiler more freedom to optimize. Here are some examples of (potentially
2168 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2169
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2170
2171<div class="doc_code">
2172<pre>
2173 %A = add %X, undef
2174 %B = sub %X, undef
2175 %C = xor %X, undef
2176Safe:
2177 %A = undef
2178 %B = undef
2179 %C = undef
2180</pre>
2181</div>
2182
2183<p>This is safe because all of the output bits are affected by the undef bits.
2184Any output bit can have a zero or one depending on the input bits.</p>
2185
2186<div class="doc_code">
2187<pre>
2188 %A = or %X, undef
2189 %B = and %X, undef
2190Safe:
2191 %A = -1
2192 %B = 0
2193Unsafe:
2194 %A = undef
2195 %B = undef
2196</pre>
2197</div>
2198
2199<p>These logical operations have bits that are not always affected by the input.
2200For example, if "%X" has a zero bit, then the output of the 'and' operation will
2201always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2202such, it is unsafe to optimize or assume that the result of the and is undef.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2203However, it is safe to assume that all bits of the undef could be 0, and
2204optimize the and to 0. Likewise, it is safe to assume that all the bits of
2205the undef operand to the or could be set, allowing the or to be folded to
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2206-1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2207
2208<div class="doc_code">
2209<pre>
2210 %A = select undef, %X, %Y
2211 %B = select undef, 42, %Y
2212 %C = select %X, %Y, undef
2213Safe:
2214 %A = %X (or %Y)
2215 %B = 42 (or %Y)
2216 %C = %Y
2217Unsafe:
2218 %A = undef
2219 %B = undef
2220 %C = undef
2221</pre>
2222</div>
2223
2224<p>This set of examples show that undefined select (and conditional branch)
2225conditions can go "either way" but they have to come from one of the two
2226operands. In the %A example, if %X and %Y were both known to have a clear low
2227bit, then %A would have to have a cleared low bit. However, in the %C example,
2228the optimizer is allowed to assume that the undef operand could be the same as
2229%Y, allowing the whole select to be eliminated.</p>
2230
2231
2232<div class="doc_code">
2233<pre>
2234 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2235
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2236 %B = undef
2237 %C = xor %B, %B
2238
2239 %D = undef
2240 %E = icmp lt %D, 4
2241 %F = icmp gte %D, 4
2242
2243Safe:
2244 %A = undef
2245 %B = undef
2246 %C = undef
2247 %D = undef
2248 %E = undef
2249 %F = undef
2250</pre>
2251</div>
2252
2253<p>This example points out that two undef operands are not necessarily the same.
2254This can be surprising to people (and also matches C semantics) where they
2255assume that "X^X" is always zero, even if X is undef. This isn't true for a
2256number of reasons, but the short answer is that an undef "variable" can
2257arbitrarily change its value over its "live range". This is true because the
2258"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2259logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2260so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner6760e542009-09-08 15:13:16 +0000[diff] [blame]2261to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2262would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2263
2264<div class="doc_code">
2265<pre>
2266 %A = fdiv undef, %X
2267 %B = fdiv %X, undef
2268Safe:
2269 %A = undef
2270b: unreachable
2271</pre>
2272</div>
2273
2274<p>These examples show the crucial difference between an <em>undefined
2275value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2276allowed to have an arbitrary bit-pattern. This means that the %A operation
2277can be constant folded to undef because the undef could be an SNaN, and fdiv is
2278not (currently) defined on SNaN's. However, in the second example, we can make
2279a more aggressive assumption: because the undef is allowed to be an arbitrary
2280value, we are allowed to assume that it could be zero. Since a divide by zero
Chris Lattner10ff0c12009-09-08 19:45:34 +0000[diff] [blame]2281has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2282does not execute at all. This allows us to delete the divide and all code after
2283it: since the undefined operation "can't happen", the optimizer can assume that
2284it occurs in dead code.
2285</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2286
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2287<div class="doc_code">
2288<pre>
2289a: store undef -> %X
2290b: store %X -> undef
2291Safe:
2292a: &lt;deleted&gt;
2293b: unreachable
2294</pre>
2295</div>
2296
2297<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2298can be assumed to not have any effect: we can assume that the value is
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2299overwritten with bits that happen to match what was already there. However, a
2300store "to" an undefined location could clobber arbitrary memory, therefore, it
2301has undefined behavior.</p>
2302
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2303</div>
2304
2305<!-- ======================================================================= -->
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2306<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2307 Blocks</a></div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2308<div class="doc_text">
2309
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2310<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2311
2312<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2313 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2314 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2315
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2316<p>This value only has defined behavior when used as an operand to the
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2317 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2318 against null. Pointer equality tests between labels addresses is undefined
2319 behavior - though, again, comparison against null is ok, and no label is
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2320 equal to the null pointer. This may also be passed around as an opaque
2321 pointer sized value as long as the bits are not inspected. This allows
Chris Lattnerda37b302009-10-27 21:44:20 +0000[diff] [blame]2322 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2323 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2324
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2325<p>Finally, some targets may provide defined semantics when
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2326 using the value as the operand to an inline assembly, but that is target
2327 specific.
2328 </p>
2329
2330</div>
2331
2332
2333<!-- ======================================================================= -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2334<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2335</div>
2336
2337<div class="doc_text">
2338
2339<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2340 to be used as constants. Constant expressions may be of
2341 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2342 operation that does not have side effects (e.g. load and call are not
2343 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2344
2345<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2346 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2347 <dd>Truncate a constant to another type. The bit size of CST must be larger
2348 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2349
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2350 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2351 <dd>Zero extend a constant to another type. The bit size of CST must be
2352 smaller or equal to the bit size of TYPE. Both types must be
2353 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2354
2355 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2356 <dd>Sign extend a constant to another type. The bit size of CST must be
2357 smaller or equal to the bit size of TYPE. Both types must be
2358 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2359
2360 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2361 <dd>Truncate a floating point constant to another floating point type. The
2362 size of CST must be larger than the size of TYPE. Both types must be
2363 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2364
2365 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2366 <dd>Floating point extend a constant to another type. The size of CST must be
2367 smaller or equal to the size of TYPE. Both types must be floating
2368 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2369
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2370 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2371 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2372 constant. TYPE must be a scalar or vector integer type. CST must be of
2373 scalar or vector floating point type. Both CST and TYPE must be scalars,
2374 or vectors of the same number of elements. If the value won't fit in the
2375 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2376
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2377 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2378 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2379 constant. TYPE must be a scalar or vector integer type. CST must be of
2380 scalar or vector floating point type. Both CST and TYPE must be scalars,
2381 or vectors of the same number of elements. If the value won't fit in the
2382 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2383
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2384 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2385 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2386 constant. TYPE must be a scalar or vector floating point type. CST must be
2387 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2388 vectors of the same number of elements. If the value won't fit in the
2389 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2390
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2391 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2392 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2393 constant. TYPE must be a scalar or vector floating point type. CST must be
2394 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2395 vectors of the same number of elements. If the value won't fit in the
2396 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2397
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2398 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2399 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2400 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2401 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2402 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2403
2404 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2405 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2406 type. CST must be of integer type. The CST value is zero extended,
2407 truncated, or unchanged to make it fit in a pointer size. This one is
2408 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2409
2410 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2411 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2412 are the same as those for the <a href="#i_bitcast">bitcast
2413 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2414
2415 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2416 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2417 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2418 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2419 instruction, the index list may have zero or more indexes, which are
2420 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2421
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2422 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2423 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2424
2425 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2426 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2427
2428 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2429 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2430
2431 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2432 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2433 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2434
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2435 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2436 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2437 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2438
2439 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2440 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2441 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2442
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2443 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2444 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2445 be any of the <a href="#binaryops">binary</a>
2446 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2447 on operands are the same as those for the corresponding instruction
2448 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2449</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2450
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2451</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2452
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2453<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2454<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2455<!-- *********************************************************************** -->
2456
2457<!-- ======================================================================= -->
2458<div class="doc_subsection">
2459<a name="inlineasm">Inline Assembler Expressions</a>
2460</div>
2461
2462<div class="doc_text">
2463
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2464<p>LLVM supports inline assembler expressions (as opposed
2465 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2466 a special value. This value represents the inline assembler as a string
2467 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2468 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2469 expression has side effects, and a flag indicating whether the function
2470 containing the asm needs to align its stack conservatively. An example
2471 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2472
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2473<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2474<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2475i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2476</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2477</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2478
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2479<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2480 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2481 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2482
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2483<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2484<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2485%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2486</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2487</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2488
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2489<p>Inline asms with side effects not visible in the constraint list must be
2490 marked as having side effects. This is done through the use of the
2491 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2492
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2493<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2494<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2495call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2496</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2497</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2498
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2499<p>In some cases inline asms will contain code that will not work unless the
2500 stack is aligned in some way, such as calls or SSE instructions on x86,
2501 yet will not contain code that does that alignment within the asm.
2502 The compiler should make conservative assumptions about what the asm might
2503 contain and should generate its usual stack alignment code in the prologue
2504 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2505
2506<div class="doc_code">
2507<pre>
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2508call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2509</pre>
2510</div>
2511
2512<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2513 first.</p>
2514
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2515<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2516 documented here. Constraints on what can be done (e.g. duplication, moving,
2517 etc need to be documented). This is probably best done by reference to
2518 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2519
2520</div>
2521
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2522<!-- ======================================================================= -->
2523<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2524 Strings</a>
2525</div>
2526
2527<div class="doc_text">
2528
2529<p>LLVM IR allows metadata to be attached to instructions in the program that
2530 can convey extra information about the code to the optimizers and code
2531 generator. One example application of metadata is source-level debug
2532 information. There are two metadata primitives: strings and nodes. All
2533 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2534 preceding exclamation point ('<tt>!</tt>').</p>
2535
2536<p>A metadata string is a string surrounded by double quotes. It can contain
2537 any character by escaping non-printable characters with "\xx" where "xx" is
2538 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2539
2540<p>Metadata nodes are represented with notation similar to structure constants
2541 (a comma separated list of elements, surrounded by braces and preceded by an
2542 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2543 10}</tt>". Metadata nodes can have any values as their operand.</p>
2544
2545<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2546 metadata nodes, which can be looked up in the module symbol table. For
2547 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2548
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2549<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
2550 function is using two metadata arguments.
2551
2552 <div class="doc_code">
2553 <pre>
2554 call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2555 </pre>
2556 </div></p>
2557
2558<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
2559 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.
2560
2561 <div class="doc_code">
2562 <pre>
2563 %indvar.next = add i64 %indvar, 1, !dbg !21
2564 </pre>
2565 </div></p>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2566</div>
2567
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2568
2569<!-- *********************************************************************** -->
2570<div class="doc_section">
2571 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2572</div>
2573<!-- *********************************************************************** -->
2574
2575<p>LLVM has a number of "magic" global variables that contain data that affect
2576code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2577of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2578section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2579by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2580
2581<!-- ======================================================================= -->
2582<div class="doc_subsection">
2583<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2584</div>
2585
2586<div class="doc_text">
2587
2588<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2589href="#linkage_appending">appending linkage</a>. This array contains a list of
2590pointers to global variables and functions which may optionally have a pointer
2591cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2592
2593<pre>
2594 @X = global i8 4
2595 @Y = global i32 123
2596
2597 @llvm.used = appending global [2 x i8*] [
2598 i8* @X,
2599 i8* bitcast (i32* @Y to i8*)
2600 ], section "llvm.metadata"
2601</pre>
2602
2603<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2604compiler, assembler, and linker are required to treat the symbol as if there is
2605a reference to the global that it cannot see. For example, if a variable has
2606internal linkage and no references other than that from the <tt>@llvm.used</tt>
2607list, it cannot be deleted. This is commonly used to represent references from
2608inline asms and other things the compiler cannot "see", and corresponds to
2609"attribute((used))" in GNU C.</p>
2610
2611<p>On some targets, the code generator must emit a directive to the assembler or
2612object file to prevent the assembler and linker from molesting the symbol.</p>
2613
2614</div>
2615
2616<!-- ======================================================================= -->
2617<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2618<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2619</div>
2620
2621<div class="doc_text">
2622
2623<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2624<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2625touching the symbol. On targets that support it, this allows an intelligent
2626linker to optimize references to the symbol without being impeded as it would be
2627by <tt>@llvm.used</tt>.</p>
2628
2629<p>This is a rare construct that should only be used in rare circumstances, and
2630should not be exposed to source languages.</p>
2631
2632</div>
2633
2634<!-- ======================================================================= -->
2635<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2636<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2637</div>
2638
2639<div class="doc_text">
2640
2641<p>TODO: Describe this.</p>
2642
2643</div>
2644
2645<!-- ======================================================================= -->
2646<div class="doc_subsection">
2647<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2648</div>
2649
2650<div class="doc_text">
2651
2652<p>TODO: Describe this.</p>
2653
2654</div>
2655
2656
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2657<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2658<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2659<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2660
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2661<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2662
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2663<p>The LLVM instruction set consists of several different classifications of
2664 instructions: <a href="#terminators">terminator
2665 instructions</a>, <a href="#binaryops">binary instructions</a>,
2666 <a href="#bitwiseops">bitwise binary instructions</a>,
2667 <a href="#memoryops">memory instructions</a>, and
2668 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2669
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2670</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2671
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2672<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2673<div class="doc_subsection"> <a name="terminators">Terminator
2674Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2675
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2676<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2677
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2678<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2679 in a program ends with a "Terminator" instruction, which indicates which
2680 block should be executed after the current block is finished. These
2681 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2682 control flow, not values (the one exception being the
2683 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2684
2685<p>There are six different terminator instructions: the
2686 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2687 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2688 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2689 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2690 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2691 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2692 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2693
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2694</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2696<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2697<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2698Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2699
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2700<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2701
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2702<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2703<pre>
2704 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2705 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2706</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2707
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2708<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2709<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2710 a value) from a function back to the caller.</p>
2711
2712<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2713 value and then causes control flow, and one that just causes control flow to
2714 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2715
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2716<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2717<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2718 return value. The type of the return value must be a
2719 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2720
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2721<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2722 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2723 value or a return value with a type that does not match its type, or if it
2724 has a void return type and contains a '<tt>ret</tt>' instruction with a
2725 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2726
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2727<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2728<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2729 the calling function's context. If the caller is a
2730 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2731 instruction after the call. If the caller was an
2732 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2733 the beginning of the "normal" destination block. If the instruction returns
2734 a value, that value shall set the call or invoke instruction's return
2735 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2736
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2737<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2738<pre>
2739 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2740 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2741 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2742</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2743
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2744</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2745<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2746<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2747
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2748<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2749
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2750<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2751<pre>
2752 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2753</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2754
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2755<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2756<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2757 different basic block in the current function. There are two forms of this
2758 instruction, corresponding to a conditional branch and an unconditional
2759 branch.</p>
2760
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2761<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2762<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2763 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2764 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2765 target.</p>
2766
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2767<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2768<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2769 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2770 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2771 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2772
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2774<pre>
2775Test:
2776 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2777 br i1 %cond, label %IfEqual, label %IfUnequal
2778IfEqual:
2779 <a href="#i_ret">ret</a> i32 1
2780IfUnequal:
2781 <a href="#i_ret">ret</a> i32 0
2782</pre>
2783
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2784</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2785
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2786<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2787<div class="doc_subsubsection">
2788 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2789</div>
2790
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2791<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2792
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2793<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2794<pre>
2795 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2796</pre>
2797
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2798<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2799<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2800 several different places. It is a generalization of the '<tt>br</tt>'
2801 instruction, allowing a branch to occur to one of many possible
2802 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2803
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2804<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2805<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2806 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2807 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2808 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2809
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2810<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2811<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2812 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2813 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2814 transferred to the corresponding destination; otherwise, control flow is
2815 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2816
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2817<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2818<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2819 <tt>switch</tt> instruction, this instruction may be code generated in
2820 different ways. For example, it could be generated as a series of chained
2821 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2822
2823<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2824<pre>
2825 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2826 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2827 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2828
2829 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2830 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2831
2832 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2833 switch i32 %val, label %otherwise [ i32 0, label %onzero
2834 i32 1, label %onone
2835 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2836</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2837
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2838</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2839
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2840
2841<!-- _______________________________________________________________________ -->
2842<div class="doc_subsubsection">
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2843 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2844</div>
2845
2846<div class="doc_text">
2847
2848<h5>Syntax:</h5>
2849<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2850 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2851</pre>
2852
2853<h5>Overview:</h5>
2854
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2855<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2856 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2857 "<tt>address</tt>". Address must be derived from a <a
2858 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2859
2860<h5>Arguments:</h5>
2861
2862<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2863 rest of the arguments indicate the full set of possible destinations that the
2864 address may point to. Blocks are allowed to occur multiple times in the
2865 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2866
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2867<p>This destination list is required so that dataflow analysis has an accurate
2868 understanding of the CFG.</p>
2869
2870<h5>Semantics:</h5>
2871
2872<p>Control transfers to the block specified in the address argument. All
2873 possible destination blocks must be listed in the label list, otherwise this
2874 instruction has undefined behavior. This implies that jumps to labels
2875 defined in other functions have undefined behavior as well.</p>
2876
2877<h5>Implementation:</h5>
2878
2879<p>This is typically implemented with a jump through a register.</p>
2880
2881<h5>Example:</h5>
2882<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2883 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2884</pre>
2885
2886</div>
2887
2888
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2889<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2890<div class="doc_subsubsection">
2891 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2892</div>
2893
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2894<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2895
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2896<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2897<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2898 &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 Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]2899 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2900</pre>
2901
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2902<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2903<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2904 function, with the possibility of control flow transfer to either the
2905 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2906 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2907 control flow will return to the "normal" label. If the callee (or any
2908 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2909 instruction, control is interrupted and continued at the dynamically nearest
2910 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2911
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2912<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2913<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2914
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2915<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2916 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2917 convention</a> the call should use. If none is specified, the call
2918 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2919
2920 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2921 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2922 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2923
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2924 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2925 function value being invoked. In most cases, this is a direct function
2926 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2927 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2928
2929 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2930 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2931
2932 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]2933 signature argument types and parameter attributes. All arguments must be
2934 of <a href="#t_firstclass">first class</a> type. If the function
2935 signature indicates the function accepts a variable number of arguments,
2936 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2937
2938 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2939 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2940
2941 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2942 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2943
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2944 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2945 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2946 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2947</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2948
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2949<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2950<p>This instruction is designed to operate as a standard
2951 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2952 primary difference is that it establishes an association with a label, which
2953 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2954
2955<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2956 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2957 exception. Additionally, this is important for implementation of
2958 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2959
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2960<p>For the purposes of the SSA form, the definition of the value returned by the
2961 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2962 block to the "normal" label. If the callee unwinds then no return value is
2963 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2964
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]2965<p>Note that the code generator does not yet completely support unwind, and
2966that the invoke/unwind semantics are likely to change in future versions.</p>
2967
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2968<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2969<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2970 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2971 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2972 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2973 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2974</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2975
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2976</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2977
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2978<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2979
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2980<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2981Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2982
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2983<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2984
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2985<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2986<pre>
2987 unwind
2988</pre>
2989
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2990<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2991<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2992 at the first callee in the dynamic call stack which used
2993 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2994 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2995
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2996<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2997<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2998 immediately halt. The dynamic call stack is then searched for the
2999 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3000 Once found, execution continues at the "exceptional" destination block
3001 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3002 instruction in the dynamic call chain, undefined behavior results.</p>
3003
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3004<p>Note that the code generator does not yet completely support unwind, and
3005that the invoke/unwind semantics are likely to change in future versions.</p>
3006
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3007</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3008
3009<!-- _______________________________________________________________________ -->
3010
3011<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
3012Instruction</a> </div>
3013
3014<div class="doc_text">
3015
3016<h5>Syntax:</h5>
3017<pre>
3018 unreachable
3019</pre>
3020
3021<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3022<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3023 instruction is used to inform the optimizer that a particular portion of the
3024 code is not reachable. This can be used to indicate that the code after a
3025 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3026
3027<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3028<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3029
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3030</div>
3031
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3032<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3033<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3034
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3035<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3036
3037<p>Binary operators are used to do most of the computation in a program. They
3038 require two operands of the same type, execute an operation on them, and
3039 produce a single value. The operands might represent multiple data, as is
3040 the case with the <a href="#t_vector">vector</a> data type. The result value
3041 has the same type as its operands.</p>
3042
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3043<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3044
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3045</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3046
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3047<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3048<div class="doc_subsubsection">
3049 <a name="i_add">'<tt>add</tt>' Instruction</a>
3050</div>
3051
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3052<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3053
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3054<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3055<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3056 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3057 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3058 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3059 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3060</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3061
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3062<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3063<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3064
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3065<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3066<p>The two arguments to the '<tt>add</tt>' instruction must
3067 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3068 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3069
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3070<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3071<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3072
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3073<p>If the sum has unsigned overflow, the result returned is the mathematical
3074 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3075
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3076<p>Because LLVM integers use a two's complement representation, this instruction
3077 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3078
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3079<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3080 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3081 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
3082 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3083
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3084<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3085<pre>
3086 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3087</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3088
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3089</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3090
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3091<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3092<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3093 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3094</div>
3095
3096<div class="doc_text">
3097
3098<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3099<pre>
3100 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3101</pre>
3102
3103<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3104<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3105
3106<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3107<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3108 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3109 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3110
3111<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3112<p>The value produced is the floating point sum of the two operands.</p>
3113
3114<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3115<pre>
3116 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3117</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3118
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3119</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3120
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3121<!-- _______________________________________________________________________ -->
3122<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3123 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3124</div>
3125
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3126<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3127
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3128<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3129<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3130 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3131 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3132 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3133 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3134</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3135
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3136<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3137<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3138 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3139
3140<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3141 '<tt>neg</tt>' instruction present in most other intermediate
3142 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3143
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3144<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3145<p>The two arguments to the '<tt>sub</tt>' instruction must
3146 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3147 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3148
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3149<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3150<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3151
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3152<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3153 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3154 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3155
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3156<p>Because LLVM integers use a two's complement representation, this instruction
3157 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3158
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3159<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3160 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3161 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
3162 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3163
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3164<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3165<pre>
3166 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3167 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3168</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3169
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3170</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3171
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3172<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3173<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3174 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3175</div>
3176
3177<div class="doc_text">
3178
3179<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3180<pre>
3181 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3182</pre>
3183
3184<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3185<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3186 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3187
3188<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3189 '<tt>fneg</tt>' instruction present in most other intermediate
3190 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3191
3192<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3193<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3194 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3195 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3196
3197<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3198<p>The value produced is the floating point difference of the two operands.</p>
3199
3200<h5>Example:</h5>
3201<pre>
3202 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3203 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3204</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3205
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3206</div>
3207
3208<!-- _______________________________________________________________________ -->
3209<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3210 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3211</div>
3212
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3213<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3214
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3215<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3216<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3217 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3218 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3219 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3220 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3221</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3222
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3223<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3224<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3225
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3226<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3227<p>The two arguments to the '<tt>mul</tt>' instruction must
3228 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3229 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3230
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3231<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3232<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3233
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3234<p>If the result of the multiplication has unsigned overflow, the result
3235 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3236 width of the result.</p>
3237
3238<p>Because LLVM integers use a two's complement representation, and the result
3239 is the same width as the operands, this instruction returns the correct
3240 result for both signed and unsigned integers. If a full product
3241 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3242 be sign-extended or zero-extended as appropriate to the width of the full
3243 product.</p>
3244
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3245<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3246 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3247 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3248 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3249
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3250<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3251<pre>
3252 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3253</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3254
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3255</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3256
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3257<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3258<div class="doc_subsubsection">
3259 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3260</div>
3261
3262<div class="doc_text">
3263
3264<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3265<pre>
3266 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3267</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3268
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3269<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3270<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3271
3272<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3273<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3274 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3275 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3276
3277<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3278<p>The value produced is the floating point product of the two operands.</p>
3279
3280<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3281<pre>
3282 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3283</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3284
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3285</div>
3286
3287<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3288<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3289</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3290
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3291<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3292
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3293<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3294<pre>
3295 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3296</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3297
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3298<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3299<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3300
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3301<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3302<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3303 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3304 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3305
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3306<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3307<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3308
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3309<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3310 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3311
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3312<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3313
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3314<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3315<pre>
3316 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3317</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3318
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3319</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3320
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3321<!-- _______________________________________________________________________ -->
3322<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3323</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3324
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3325<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3326
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3327<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3328<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3329 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3330 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3331</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3332
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3333<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3334<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3335
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3336<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3337<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3338 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3339 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3340
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3341<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3342<p>The value produced is the signed integer quotient of the two operands rounded
3343 towards zero.</p>
3344
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3345<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3346 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3347
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3348<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3349 undefined behavior; this is a rare case, but can occur, for example, by doing
3350 a 32-bit division of -2147483648 by -1.</p>
3351
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3352<p>If the <tt>exact</tt> keyword is present, the result value of the
3353 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3354 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3355
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3356<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3357<pre>
3358 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3359</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3360
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3361</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3362
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3363<!-- _______________________________________________________________________ -->
3364<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3365Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3366
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3367<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3369<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3370<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3371 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3372</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3373
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3374<h5>Overview:</h5>
3375<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3376
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3377<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3378<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3379 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3380 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3381
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3382<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3383<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3384
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3385<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3386<pre>
3387 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3388</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3389
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3390</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3391
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3392<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3393<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3394</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3395
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3396<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3397
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3398<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3399<pre>
3400 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3401</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3402
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3403<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3404<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3405 division of its two arguments.</p>
3406
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3407<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3408<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3409 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3410 values. Both arguments must have identical types.</p>
3411
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3412<h5>Semantics:</h5>
3413<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3414 This instruction always performs an unsigned division to get the
3415 remainder.</p>
3416
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3417<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3418 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3419
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3420<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3421
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3422<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3423<pre>
3424 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3425</pre>
3426
3427</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3428
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3429<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3430<div class="doc_subsubsection">
3431 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3432</div>
3433
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3434<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3435
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3436<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3437<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3438 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3439</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3440
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3441<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3442<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3443 division of its two operands. This instruction can also take
3444 <a href="#t_vector">vector</a> versions of the values in which case the
3445 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3446
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3447<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3448<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3449 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3450 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3451
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3452<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3453<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3454 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3455 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3456 a value. For more information about the difference,
3457 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3458 Math Forum</a>. For a table of how this is implemented in various languages,
3459 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3460 Wikipedia: modulo operation</a>.</p>
3461
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3462<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3464
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3465<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3466 Overflow also leads to undefined behavior; this is a rare case, but can
3467 occur, for example, by taking the remainder of a 32-bit division of
3468 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3469 lets srem be implemented using instructions that return both the result of
3470 the division and the remainder.)</p>
3471
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3472<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3473<pre>
3474 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3475</pre>
3476
3477</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3478
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3479<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3480<div class="doc_subsubsection">
3481 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3482
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3483<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3484
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3485<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3486<pre>
3487 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3488</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3489
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3490<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3491<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3492 its two operands.</p>
3493
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3494<h5>Arguments:</h5>
3495<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3496 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3497 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3498
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3499<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3500<p>This instruction returns the <i>remainder</i> of a division. The remainder
3501 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3502
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3503<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3504<pre>
3505 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3506</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3507
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3508</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3509
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3510<!-- ======================================================================= -->
3511<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3512Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3513
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3514<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3515
3516<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3517 program. They are generally very efficient instructions and can commonly be
3518 strength reduced from other instructions. They require two operands of the
3519 same type, execute an operation on them, and produce a single value. The
3520 resulting value is the same type as its operands.</p>
3521
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3522</div>
3523
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3524<!-- _______________________________________________________________________ -->
3525<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3526Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3527
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3528<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3529
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3530<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3531<pre>
3532 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3533</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3534
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3535<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3536<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3537 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3538
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3539<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3540<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3541 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3542 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3543
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3544<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3545<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3546 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3547 is (statically or dynamically) negative or equal to or larger than the number
3548 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3549 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3550 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3551
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3552<h5>Example:</h5>
3553<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3554 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3555 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3556 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3557 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3558 &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 Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3559</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3560
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3561</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3562
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3563<!-- _______________________________________________________________________ -->
3564<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3565Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3566
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3567<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3568
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3569<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3570<pre>
3571 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3572</pre>
3573
3574<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3575<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3576 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3577
3578<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3579<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3580 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3581 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3582
3583<h5>Semantics:</h5>
3584<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3585 significant bits of the result will be filled with zero bits after the shift.
3586 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3587 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3588 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3589 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3590
3591<h5>Example:</h5>
3592<pre>
3593 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3594 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3595 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3596 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3597 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3598 &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 Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3599</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3600
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3601</div>
3602
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3603<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3604<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3605Instruction</a> </div>
3606<div class="doc_text">
3607
3608<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3609<pre>
3610 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3611</pre>
3612
3613<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3614<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3615 operand shifted to the right a specified number of bits with sign
3616 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3617
3618<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3619<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3620 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3621 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3622
3623<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3624<p>This instruction always performs an arithmetic shift right operation, The
3625 most significant bits of the result will be filled with the sign bit
3626 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3627 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3628 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3629 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3630
3631<h5>Example:</h5>
3632<pre>
3633 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3634 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3635 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3636 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3637 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3638 &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 Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3639</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3640
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3641</div>
3642
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3643<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3644<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3645Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3646
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3647<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3648
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3649<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3650<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3651 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3652</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3653
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3654<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3656 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3657
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3658<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3659<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3660 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3661 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3662
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3663<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3664<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3666<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3667 <tbody>
3668 <tr>
3669 <td>In0</td>
3670 <td>In1</td>
3671 <td>Out</td>
3672 </tr>
3673 <tr>
3674 <td>0</td>
3675 <td>0</td>
3676 <td>0</td>
3677 </tr>
3678 <tr>
3679 <td>0</td>
3680 <td>1</td>
3681 <td>0</td>
3682 </tr>
3683 <tr>
3684 <td>1</td>
3685 <td>0</td>
3686 <td>0</td>
3687 </tr>
3688 <tr>
3689 <td>1</td>
3690 <td>1</td>
3691 <td>1</td>
3692 </tr>
3693 </tbody>
3694</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3696<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3697<pre>
3698 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3699 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3700 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3701</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3702</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3703<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3704<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3705
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3706<div class="doc_text">
3707
3708<h5>Syntax:</h5>
3709<pre>
3710 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3711</pre>
3712
3713<h5>Overview:</h5>
3714<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3715 two operands.</p>
3716
3717<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3718<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3719 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3720 values. Both arguments must have identical types.</p>
3721
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3722<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3723<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3724
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3725<table border="1" cellspacing="0" cellpadding="4">
3726 <tbody>
3727 <tr>
3728 <td>In0</td>
3729 <td>In1</td>
3730 <td>Out</td>
3731 </tr>
3732 <tr>
3733 <td>0</td>
3734 <td>0</td>
3735 <td>0</td>
3736 </tr>
3737 <tr>
3738 <td>0</td>
3739 <td>1</td>
3740 <td>1</td>
3741 </tr>
3742 <tr>
3743 <td>1</td>
3744 <td>0</td>
3745 <td>1</td>
3746 </tr>
3747 <tr>
3748 <td>1</td>
3749 <td>1</td>
3750 <td>1</td>
3751 </tr>
3752 </tbody>
3753</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3754
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3755<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3756<pre>
3757 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3758 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3759 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3760</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3761
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3762</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3763
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3764<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3765<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3766Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3767
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3768<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3769
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3770<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3771<pre>
3772 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3773</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3774
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3775<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3776<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3777 its two operands. The <tt>xor</tt> is used to implement the "one's
3778 complement" operation, which is the "~" operator in C.</p>
3779
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3780<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3781<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3782 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3783 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3784
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3785<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3786<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3787
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3788<table border="1" cellspacing="0" cellpadding="4">
3789 <tbody>
3790 <tr>
3791 <td>In0</td>
3792 <td>In1</td>
3793 <td>Out</td>
3794 </tr>
3795 <tr>
3796 <td>0</td>
3797 <td>0</td>
3798 <td>0</td>
3799 </tr>
3800 <tr>
3801 <td>0</td>
3802 <td>1</td>
3803 <td>1</td>
3804 </tr>
3805 <tr>
3806 <td>1</td>
3807 <td>0</td>
3808 <td>1</td>
3809 </tr>
3810 <tr>
3811 <td>1</td>
3812 <td>1</td>
3813 <td>0</td>
3814 </tr>
3815 </tbody>
3816</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3817
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3818<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819<pre>
3820 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3821 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3822 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3823 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3824</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3825
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3826</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3827
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3828<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3829<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3830 <a name="vectorops">Vector Operations</a>
3831</div>
3832
3833<div class="doc_text">
3834
3835<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3836 target-independent manner. These instructions cover the element-access and
3837 vector-specific operations needed to process vectors effectively. While LLVM
3838 does directly support these vector operations, many sophisticated algorithms
3839 will want to use target-specific intrinsics to take full advantage of a
3840 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3841
3842</div>
3843
3844<!-- _______________________________________________________________________ -->
3845<div class="doc_subsubsection">
3846 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3847</div>
3848
3849<div class="doc_text">
3850
3851<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3852<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3853 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3854</pre>
3855
3856<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3857<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3858 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3859
3860
3861<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3862<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3863 of <a href="#t_vector">vector</a> type. The second operand is an index
3864 indicating the position from which to extract the element. The index may be
3865 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3866
3867<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3868<p>The result is a scalar of the same type as the element type of
3869 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3870 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3871 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3872
3873<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3874<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3875 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3876</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3877
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3878</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3879
3880<!-- _______________________________________________________________________ -->
3881<div class="doc_subsubsection">
3882 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3883</div>
3884
3885<div class="doc_text">
3886
3887<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3888<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3889 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3890</pre>
3891
3892<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3893<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3894 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3895
3896<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3897<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3898 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3899 whose type must equal the element type of the first operand. The third
3900 operand is an index indicating the position at which to insert the value.
3901 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3902
3903<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3904<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3905 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3906 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3907 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3908
3909<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3910<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3911 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3912</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3913
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3914</div>
3915
3916<!-- _______________________________________________________________________ -->
3917<div class="doc_subsubsection">
3918 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3919</div>
3920
3921<div class="doc_text">
3922
3923<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3924<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3925 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3926</pre>
3927
3928<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3929<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3930 from two input vectors, returning a vector with the same element type as the
3931 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3932
3933<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3934<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3935 with types that match each other. The third argument is a shuffle mask whose
3936 element type is always 'i32'. The result of the instruction is a vector
3937 whose length is the same as the shuffle mask and whose element type is the
3938 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3939
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3940<p>The shuffle mask operand is required to be a constant vector with either
3941 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3942
3943<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3944<p>The elements of the two input vectors are numbered from left to right across
3945 both of the vectors. The shuffle mask operand specifies, for each element of
3946 the result vector, which element of the two input vectors the result element
3947 gets. The element selector may be undef (meaning "don't care") and the
3948 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3949
3950<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3951<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3952 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3953 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3954 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3955 &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 Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3956 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3957 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3958 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3959 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3960</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3961
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3962</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3963
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3964<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3965<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3966 <a name="aggregateops">Aggregate Operations</a>
3967</div>
3968
3969<div class="doc_text">
3970
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3971<p>LLVM supports several instructions for working with
3972 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3973
3974</div>
3975
3976<!-- _______________________________________________________________________ -->
3977<div class="doc_subsubsection">
3978 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3979</div>
3980
3981<div class="doc_text">
3982
3983<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3984<pre>
3985 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3986</pre>
3987
3988<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3989<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
3990 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3991
3992<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3993<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3994 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
3995 <a href="#t_array">array</a> type. The operands are constant indices to
3996 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3997 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3998
3999<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4000<p>The result is the value at the position in the aggregate specified by the
4001 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4002
4003<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4004<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4005 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4006</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4007
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4008</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4009
4010<!-- _______________________________________________________________________ -->
4011<div class="doc_subsubsection">
4012 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
4013</div>
4014
4015<div class="doc_text">
4016
4017<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4018<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]4019 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt; <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4020</pre>
4021
4022<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4023<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4024 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4025
4026<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4027<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4028 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4029 <a href="#t_array">array</a> type. The second operand is a first-class
4030 value to insert. The following operands are constant indices indicating
4031 the position at which to insert the value in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4032 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
4033 value to insert must have the same type as the value identified by the
4034 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4035
4036<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4037<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4038 that of <tt>val</tt> except that the value at the position specified by the
4039 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4040
4041<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4042<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]4043 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4044 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4045</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4046
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4047</div>
4048
4049
4050<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4051<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4052 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4053</div>
4054
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4055<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4056
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4057<p>A key design point of an SSA-based representation is how it represents
4058 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4059 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4060 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4061
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4062</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4063
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4064<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4065<div class="doc_subsubsection">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4066 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4067</div>
4068
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4069<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4070
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4071<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4072<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4073 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4074</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4075
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4076<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4077<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4078 currently executing function, to be automatically released when this function
4079 returns to its caller. The object is always allocated in the generic address
4080 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4082<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4083<p>The '<tt>alloca</tt>' instruction
4084 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4085 runtime stack, returning a pointer of the appropriate type to the program.
4086 If "NumElements" is specified, it is the number of elements allocated,
4087 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4088 specified, the value result of the allocation is guaranteed to be aligned to
4089 at least that boundary. If not specified, or if zero, the target can choose
4090 to align the allocation on any convenient boundary compatible with the
4091 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4092
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4093<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4094
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4095<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4096<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4097 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4098 memory is automatically released when the function returns. The
4099 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4100 variables that must have an address available. When the function returns
4101 (either with the <tt><a href="#i_ret">ret</a></tt>
4102 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4103 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4104
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4105<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4106<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4107 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4108 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4109 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4110 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4111</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4112
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4113</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4114
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4115<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4116<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4117Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4118
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4119<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4120
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4121<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4122<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4123 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4124 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4125 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4126</pre>
4127
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4128<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4129<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4130
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4131<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4132<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4133 from which to load. The pointer must point to
4134 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4135 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4136 number or order of execution of this <tt>load</tt> with other
4137 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4138 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4139
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4140<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4141 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4142 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4143 alignment for the target. It is the responsibility of the code emitter to
4144 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4145 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4146 produce less efficient code. An alignment of 1 is always safe.</p>
4147
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4148<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4149 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4150 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4151 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4152 and code generator that this load is not expected to be reused in the cache.
4153 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4154 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4155
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4156<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4157<p>The location of memory pointed to is loaded. If the value being loaded is of
4158 scalar type then the number of bytes read does not exceed the minimum number
4159 of bytes needed to hold all bits of the type. For example, loading an
4160 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4161 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4162 is undefined if the value was not originally written using a store of the
4163 same type.</p>
4164
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4165<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4166<pre>
4167 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4168 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4169 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4170</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4171
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4172</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4173
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4174<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4175<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4176Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4177
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]4178<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4179
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4180<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4181<pre>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4182 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4183 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4184</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4185
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4186<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4187<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4188
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4189<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4190<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4191 and an address at which to store it. The type of the
4192 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4193 the <a href="#t_firstclass">first class</a> type of the
4194 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4195 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4196 or order of execution of this <tt>store</tt> with other
4197 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4198 instructions.</p>
4199
4200<p>The optional constant "align" argument specifies the alignment of the
4201 operation (that is, the alignment of the memory address). A value of 0 or an
4202 omitted "align" argument means that the operation has the preferential
4203 alignment for the target. It is the responsibility of the code emitter to
4204 ensure that the alignment information is correct. Overestimating the
4205 alignment results in an undefined behavior. Underestimating the alignment may
4206 produce less efficient code. An alignment of 1 is always safe.</p>
4207
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4208<p>The optional !nontemporal metadata must reference a single metatadata
4209 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4210 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4211 instruction tells the optimizer and code generator that this load is
4212 not expected to be reused in the cache. The code generator may
4213 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4214 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4215
4216
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4217<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4218<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4219 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4220 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4221 does not exceed the minimum number of bytes needed to hold all bits of the
4222 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4223 writing a value of a type like <tt>i20</tt> with a size that is not an
4224 integral number of bytes, it is unspecified what happens to the extra bits
4225 that do not belong to the type, but they will typically be overwritten.</p>
4226
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4227<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4228<pre>
4229 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4230 store i32 3, i32* %ptr <i>; yields {void}</i>
4231 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4232</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4233
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4234</div>
4235
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4236<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4237<div class="doc_subsubsection">
4238 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4239</div>
4240
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4241<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4242
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4243<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4244<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4245 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4246 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4247</pre>
4248
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4249<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4250<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4251 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4252 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4253
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4254<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4255<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4256 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4257 elements of the aggregate object are indexed. The interpretation of each
4258 index is dependent on the type being indexed into. The first index always
4259 indexes the pointer value given as the first argument, the second index
4260 indexes a value of the type pointed to (not necessarily the value directly
4261 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4262 indexed into must be a pointer value, subsequent types can be arrays,
4263 vectors, structs and unions. Note that subsequent types being indexed into
4264 can never be pointers, since that would require loading the pointer before
4265 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4266
4267<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4268 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4269 integer <b>constants</b> are allowed. When indexing into an array, pointer
4270 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4271 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4272
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4273<p>For example, let's consider a C code fragment and how it gets compiled to
4274 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4275
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4276<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4277<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4278struct RT {
4279 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4280 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4281 char C;
4282};
4283struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4284 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4285 double Y;
4286 struct RT Z;
4287};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4288
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4289int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4290 return &amp;s[1].Z.B[5][13];
4291}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4292</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4293</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4294
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4295<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4296
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4297<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4298<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4299%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4300%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4301
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4302define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4303entry:
4304 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4305 ret i32* %reg
4306}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4307</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4308</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4309
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4310<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4311<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4312 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4313 }</tt>' type, a structure. The second index indexes into the third element
4314 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4315 i8 }</tt>' type, another structure. The third index indexes into the second
4316 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4317 array. The two dimensions of the array are subscripted into, yielding an
4318 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4319 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4320
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4321<p>Note that it is perfectly legal to index partially through a structure,
4322 returning a pointer to an inner element. Because of this, the LLVM code for
4323 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4324
4325<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4326 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4327 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4328 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4329 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4330 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4331 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4332 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4333 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4334</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4335
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4336<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4337 <tt>getelementptr</tt> is undefined if the base pointer is not an
4338 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4339 that would be formed by successive addition of the offsets implied by the
4340 indices to the base address with infinitely precise arithmetic are not an
4341 <i>in bounds</i> address of that allocated object.
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4342 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4343 that point into the object, plus the address one byte past the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4344
4345<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4346 the base address with silently-wrapping two's complement arithmetic, and
4347 the result value of the <tt>getelementptr</tt> may be outside the object
4348 pointed to by the base pointer. The result value may not necessarily be
4349 used to access memory though, even if it happens to point into allocated
4350 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4351 section for more information.</p>
4352
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4353<p>The getelementptr instruction is often confusing. For some more insight into
4354 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4355
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4356<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4357<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4358 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4359 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4360 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4361 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4362 <i>; yields i8*:eptr</i>
4363 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4364 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4365 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4366</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4367
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4368</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4370<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4371<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4372</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4373
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4374<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4375
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4376<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4377 which all take a single operand and a type. They perform various bit
4378 conversions on the operand.</p>
4379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4380</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4381
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4382<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4383<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4384 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4385</div>
4386<div class="doc_text">
4387
4388<h5>Syntax:</h5>
4389<pre>
4390 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4391</pre>
4392
4393<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4394<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4395 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4396
4397<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4398<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4399 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4400 size and type of the result, which must be
4401 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4402 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4403 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4404
4405<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4406<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4407 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4408 source size must be larger than the destination size, <tt>trunc</tt> cannot
4409 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4410
4411<h5>Example:</h5>
4412<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4413 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4414 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4415 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4416</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4417
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4418</div>
4419
4420<!-- _______________________________________________________________________ -->
4421<div class="doc_subsubsection">
4422 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4423</div>
4424<div class="doc_text">
4425
4426<h5>Syntax:</h5>
4427<pre>
4428 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4429</pre>
4430
4431<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4432<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4433 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4434
4435
4436<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4437<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4438 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4439 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4440 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4441 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4442
4443<h5>Semantics:</h5>
4444<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4445 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4446
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4447<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4448
4449<h5>Example:</h5>
4450<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4451 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4452 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4453</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4454
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4455</div>
4456
4457<!-- _______________________________________________________________________ -->
4458<div class="doc_subsubsection">
4459 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4460</div>
4461<div class="doc_text">
4462
4463<h5>Syntax:</h5>
4464<pre>
4465 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4466</pre>
4467
4468<h5>Overview:</h5>
4469<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4470
4471<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4472<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4473 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4474 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4475 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4476 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4477
4478<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4479<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4480 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4481 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4482
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4483<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4484
4485<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4486<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4487 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4488 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4489</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4490
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4491</div>
4492
4493<!-- _______________________________________________________________________ -->
4494<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4495 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4496</div>
4497
4498<div class="doc_text">
4499
4500<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4501<pre>
4502 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4503</pre>
4504
4505<h5>Overview:</h5>
4506<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4507 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4508
4509<h5>Arguments:</h5>
4510<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4511 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4512 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4513 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4514 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4515
4516<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4517<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4518 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4519 <a href="#t_floating">floating point</a> type. If the value cannot fit
4520 within the destination type, <tt>ty2</tt>, then the results are
4521 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4522
4523<h5>Example:</h5>
4524<pre>
4525 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4526 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4527</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4528
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4529</div>
4530
4531<!-- _______________________________________________________________________ -->
4532<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4533 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4534</div>
4535<div class="doc_text">
4536
4537<h5>Syntax:</h5>
4538<pre>
4539 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4540</pre>
4541
4542<h5>Overview:</h5>
4543<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4544 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4545
4546<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4547<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4548 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4549 a <a href="#t_floating">floating point</a> type to cast it to. The source
4550 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4551
4552<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4553<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4554 <a href="#t_floating">floating point</a> type to a larger
4555 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4556 used to make a <i>no-op cast</i> because it always changes bits. Use
4557 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4558
4559<h5>Example:</h5>
4560<pre>
4561 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4562 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4563</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4564
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4565</div>
4566
4567<!-- _______________________________________________________________________ -->
4568<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4569 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4570</div>
4571<div class="doc_text">
4572
4573<h5>Syntax:</h5>
4574<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4575 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4576</pre>
4577
4578<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4579<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4580 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4581
4582<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4583<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4584 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4585 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4586 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4587 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4588
4589<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4590<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4591 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4592 towards zero) unsigned integer value. If the value cannot fit
4593 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4594
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4595<h5>Example:</h5>
4596<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4597 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4598 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4599 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4600</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4601
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4602</div>
4603
4604<!-- _______________________________________________________________________ -->
4605<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4606 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4607</div>
4608<div class="doc_text">
4609
4610<h5>Syntax:</h5>
4611<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4612 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4613</pre>
4614
4615<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4616<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4617 <a href="#t_floating">floating point</a> <tt>value</tt> to
4618 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4619
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4620<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4621<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4622 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4623 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4624 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4625 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4626
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4627<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4628<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4629 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4630 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4631 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4632
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4633<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4634<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4635 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4636 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4637 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4638</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4639
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4640</div>
4641
4642<!-- _______________________________________________________________________ -->
4643<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4644 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4645</div>
4646<div class="doc_text">
4647
4648<h5>Syntax:</h5>
4649<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4650 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4651</pre>
4652
4653<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4654<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4655 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4656
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4657<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4658<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4659 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4660 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4661 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4662 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4663
4664<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4665<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4666 integer quantity and converts it to the corresponding floating point
4667 value. If the value cannot fit in the floating point value, the results are
4668 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4669
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4670<h5>Example:</h5>
4671<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4672 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4673 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4674</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4675
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4676</div>
4677
4678<!-- _______________________________________________________________________ -->
4679<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4680 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4681</div>
4682<div class="doc_text">
4683
4684<h5>Syntax:</h5>
4685<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4686 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4687</pre>
4688
4689<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4690<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4691 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4692
4693<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4694<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4695 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4696 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4697 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4698 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4699
4700<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4701<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4702 quantity and converts it to the corresponding floating point value. If the
4703 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4704
4705<h5>Example:</h5>
4706<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4707 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4708 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4709</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4710
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4711</div>
4712
4713<!-- _______________________________________________________________________ -->
4714<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4715 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4716</div>
4717<div class="doc_text">
4718
4719<h5>Syntax:</h5>
4720<pre>
4721 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4722</pre>
4723
4724<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4725<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4726 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4727
4728<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4729<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4730 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4731 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4732
4733<h5>Semantics:</h5>
4734<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4735 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4736 truncating or zero extending that value to the size of the integer type. If
4737 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4738 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4739 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4740 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4741
4742<h5>Example:</h5>
4743<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4744 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4745 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4746</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4747
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4748</div>
4749
4750<!-- _______________________________________________________________________ -->
4751<div class="doc_subsubsection">
4752 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4753</div>
4754<div class="doc_text">
4755
4756<h5>Syntax:</h5>
4757<pre>
4758 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4759</pre>
4760
4761<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4762<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4763 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4764
4765<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4766<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4767 value to cast, and a type to cast it to, which must be a
4768 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4769
4770<h5>Semantics:</h5>
4771<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4772 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4773 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4774 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4775 than the size of a pointer then a zero extension is done. If they are the
4776 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4777
4778<h5>Example:</h5>
4779<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4780 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4781 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4782 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4783</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4784
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4785</div>
4786
4787<!-- _______________________________________________________________________ -->
4788<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4789 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4790</div>
4791<div class="doc_text">
4792
4793<h5>Syntax:</h5>
4794<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4795 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4796</pre>
4797
4798<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4799<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4800 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4801
4802<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4803<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4804 non-aggregate first class value, and a type to cast it to, which must also be
4805 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4806 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4807 identical. If the source type is a pointer, the destination type must also be
4808 a pointer. This instruction supports bitwise conversion of vectors to
4809 integers and to vectors of other types (as long as they have the same
4810 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4811
4812<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4813<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4814 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4815 this conversion. The conversion is done as if the <tt>value</tt> had been
4816 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4817 be converted to other pointer types with this instruction. To convert
4818 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4819 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4820
4821<h5>Example:</h5>
4822<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4823 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4824 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4825 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4826</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4827
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4828</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4829
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4830<!-- ======================================================================= -->
4831<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4832
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4833<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4834
4835<p>The instructions in this category are the "miscellaneous" instructions, which
4836 defy better classification.</p>
4837
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4838</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4839
4840<!-- _______________________________________________________________________ -->
4841<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4842</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4843
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4844<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4845
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4846<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4847<pre>
4848 &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 Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4849</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4850
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4851<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4852<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4853 boolean values based on comparison of its two integer, integer vector, or
4854 pointer operands.</p>
4855
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4856<h5>Arguments:</h5>
4857<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4858 the condition code indicating the kind of comparison to perform. It is not a
4859 value, just a keyword. The possible condition code are:</p>
4860
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4861<ol>
4862 <li><tt>eq</tt>: equal</li>
4863 <li><tt>ne</tt>: not equal </li>
4864 <li><tt>ugt</tt>: unsigned greater than</li>
4865 <li><tt>uge</tt>: unsigned greater or equal</li>
4866 <li><tt>ult</tt>: unsigned less than</li>
4867 <li><tt>ule</tt>: unsigned less or equal</li>
4868 <li><tt>sgt</tt>: signed greater than</li>
4869 <li><tt>sge</tt>: signed greater or equal</li>
4870 <li><tt>slt</tt>: signed less than</li>
4871 <li><tt>sle</tt>: signed less or equal</li>
4872</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4873
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4874<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4875 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4876 typed. They must also be identical types.</p>
4877
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4878<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4879<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4880 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4881 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4882 result, as follows:</p>
4883
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4884<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4885 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4886 <tt>false</tt> otherwise. No sign interpretation is necessary or
4887 performed.</li>
4888
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4889 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4890 <tt>false</tt> otherwise. No sign interpretation is necessary or
4891 performed.</li>
4892
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4893 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4894 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4895
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4896 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4897 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4898 to <tt>op2</tt>.</li>
4899
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4900 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4901 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4902
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4903 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4904 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4905
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4906 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4907 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4908
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4909 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4910 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4911 to <tt>op2</tt>.</li>
4912
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4913 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4914 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4915
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4916 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4917 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4918</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4920<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4921 values are compared as if they were integers.</p>
4922
4923<p>If the operands are integer vectors, then they are compared element by
4924 element. The result is an <tt>i1</tt> vector with the same number of elements
4925 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4926
4927<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4928<pre>
4929 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4930 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4931 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4932 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4933 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4934 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4935</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4936
4937<p>Note that the code generator does not yet support vector types with
4938 the <tt>icmp</tt> instruction.</p>
4939
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4940</div>
4941
4942<!-- _______________________________________________________________________ -->
4943<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4944</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4945
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4946<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4947
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4948<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4949<pre>
4950 &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 Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4951</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4952
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4953<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4954<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4955 values based on comparison of its operands.</p>
4956
4957<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4958(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4959
4960<p>If the operands are floating point vectors, then the result type is a vector
4961 of boolean with the same number of elements as the operands being
4962 compared.</p>
4963
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4964<h5>Arguments:</h5>
4965<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4966 the condition code indicating the kind of comparison to perform. It is not a
4967 value, just a keyword. The possible condition code are:</p>
4968
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4969<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4970 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4971 <li><tt>oeq</tt>: ordered and equal</li>
4972 <li><tt>ogt</tt>: ordered and greater than </li>
4973 <li><tt>oge</tt>: ordered and greater than or equal</li>
4974 <li><tt>olt</tt>: ordered and less than </li>
4975 <li><tt>ole</tt>: ordered and less than or equal</li>
4976 <li><tt>one</tt>: ordered and not equal</li>
4977 <li><tt>ord</tt>: ordered (no nans)</li>
4978 <li><tt>ueq</tt>: unordered or equal</li>
4979 <li><tt>ugt</tt>: unordered or greater than </li>
4980 <li><tt>uge</tt>: unordered or greater than or equal</li>
4981 <li><tt>ult</tt>: unordered or less than </li>
4982 <li><tt>ule</tt>: unordered or less than or equal</li>
4983 <li><tt>une</tt>: unordered or not equal</li>
4984 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4985 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4986</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4987
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4988<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4989 <i>unordered</i> means that either operand may be a QNAN.</p>
4990
4991<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4992 a <a href="#t_floating">floating point</a> type or
4993 a <a href="#t_vector">vector</a> of floating point type. They must have
4994 identical types.</p>
4995
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4996<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4997<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4998 according to the condition code given as <tt>cond</tt>. If the operands are
4999 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5000 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5001 follows:</p>
5002
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5003<ol>
5004 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5005
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5006 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5007 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5008
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5009 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5010 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5011
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5012 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5013 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5014
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5015 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5016 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5017
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5018 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5019 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5020
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5021 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5022 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5023
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5024 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5025
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5026 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5027 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5028
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5029 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5030 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5031
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5032 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5033 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5034
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5035 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5036 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5037
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5038 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5039 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5040
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5041 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5042 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5043
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5044 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5045
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5046 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5047</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5048
5049<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5050<pre>
5051 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5052 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5053 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5054 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5055</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5056
5057<p>Note that the code generator does not yet support vector types with
5058 the <tt>fcmp</tt> instruction.</p>
5059
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5060</div>
5061
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5062<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]5063<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5064 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5065</div>
5066
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5067<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5068
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5069<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5070<pre>
5071 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5072</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5073
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5074<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5075<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5076 SSA graph representing the function.</p>
5077
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5078<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5079<p>The type of the incoming values is specified with the first type field. After
5080 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5081 one pair for each predecessor basic block of the current block. Only values
5082 of <a href="#t_firstclass">first class</a> type may be used as the value
5083 arguments to the PHI node. Only labels may be used as the label
5084 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5085
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5086<p>There must be no non-phi instructions between the start of a basic block and
5087 the PHI instructions: i.e. PHI instructions must be first in a basic
5088 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5089
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5090<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5091 occur on the edge from the corresponding predecessor block to the current
5092 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5093 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5094
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5095<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5096<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5097 specified by the pair corresponding to the predecessor basic block that
5098 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5099
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5100<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5101<pre>
5102Loop: ; Infinite loop that counts from 0 on up...
5103 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5104 %nextindvar = add i32 %indvar, 1
5105 br label %Loop
5106</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5107
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5108</div>
5109
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5110<!-- _______________________________________________________________________ -->
5111<div class="doc_subsubsection">
5112 <a name="i_select">'<tt>select</tt>' Instruction</a>
5113</div>
5114
5115<div class="doc_text">
5116
5117<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5118<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5119 &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>
5120
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5121 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5122</pre>
5123
5124<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5125<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5126 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5127
5128
5129<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5130<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5131 values indicating the condition, and two values of the
5132 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5133 vectors and the condition is a scalar, then entire vectors are selected, not
5134 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5135
5136<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5137<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5138 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5139
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5140<p>If the condition is a vector of i1, then the value arguments must be vectors
5141 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5142
5143<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5144<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5145 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5146</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5147
5148<p>Note that the code generator does not yet support conditions
5149 with vector type.</p>
5150
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5151</div>
5152
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5153<!-- _______________________________________________________________________ -->
5154<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5155 <a name="i_call">'<tt>call</tt>' Instruction</a>
5156</div>
5157
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5158<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5159
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5160<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5161<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5162 &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 Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5163</pre>
5164
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5165<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5166<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5167
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5168<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5169<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5170
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5171<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5172 <li>The optional "tail" marker indicates that the callee function does not
5173 access any allocas or varargs in the caller. Note that calls may be
5174 marked "tail" even if they do not occur before
5175 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5176 present, the function call is eligible for tail call optimization,
5177 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5178 optimized into a jump</a>. The code generator may optimize calls marked
5179 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5180 sibling call optimization</a> when the caller and callee have
5181 matching signatures, or 2) forced tail call optimization when the
5182 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5183 <ul>
5184 <li>Caller and callee both have the calling
5185 convention <tt>fastcc</tt>.</li>
5186 <li>The call is in tail position (ret immediately follows call and ret
5187 uses value of call or is void).</li>
5188 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5189 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5190 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5191 constraints are met.</a></li>
5192 </ul>
5193 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5194
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5195 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5196 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5197 defaults to using C calling conventions. The calling convention of the
5198 call must match the calling convention of the target function, or else the
5199 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5200
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5201 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5202 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5203 '<tt>inreg</tt>' attributes are valid here.</li>
5204
5205 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5206 type of the return value. Functions that return no value are marked
5207 <tt><a href="#t_void">void</a></tt>.</li>
5208
5209 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5210 being invoked. The argument types must match the types implied by this
5211 signature. This type can be omitted if the function is not varargs and if
5212 the function type does not return a pointer to a function.</li>
5213
5214 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5215 be invoked. In most cases, this is a direct function invocation, but
5216 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5217 to function value.</li>
5218
5219 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5220 signature argument types and parameter attributes. All arguments must be
5221 of <a href="#t_firstclass">first class</a> type. If the function
5222 signature indicates the function accepts a variable number of arguments,
5223 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5224
5225 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5226 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5227 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5228</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5229
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5230<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5231<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5232 a specified function, with its incoming arguments bound to the specified
5233 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5234 function, control flow continues with the instruction after the function
5235 call, and the return value of the function is bound to the result
5236 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5237
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5238<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5239<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5240 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5241 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5242 %X = tail call i32 @foo() <i>; yields i32</i>
5243 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5244 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5245
5246 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5247 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5248 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5249 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5250 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5251 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5252</pre>
5253
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5254<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5255standard C99 library as being the C99 library functions, and may perform
5256optimizations or generate code for them under that assumption. This is
5257something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5258freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5259
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5260</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5261
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5262<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5263<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5264 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5265</div>
5266
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5267<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5268
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5269<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5270<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5271 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5272</pre>
5273
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5274<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5275<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5276 the "variable argument" area of a function call. It is used to implement the
5277 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5278
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5279<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5280<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5281 argument. It returns a value of the specified argument type and increments
5282 the <tt>va_list</tt> to point to the next argument. The actual type
5283 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5284
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5285<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5286<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5287 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5288 to the next argument. For more information, see the variable argument
5289 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5290
5291<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5292 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5293 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5294
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5295<p><tt>va_arg</tt> is an LLVM instruction instead of
5296 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5297 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5298
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5299<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5300<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5301
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5302<p>Note that the code generator does not yet fully support va_arg on many
5303 targets. Also, it does not currently support va_arg with aggregate types on
5304 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5305
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5306</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5307
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5308<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5309<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5310<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5311
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5312<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5313
5314<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5315 well known names and semantics and are required to follow certain
5316 restrictions. Overall, these intrinsics represent an extension mechanism for
5317 the LLVM language that does not require changing all of the transformations
5318 in LLVM when adding to the language (or the bitcode reader/writer, the
5319 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5320
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5321<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5322 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5323 begin with this prefix. Intrinsic functions must always be external
5324 functions: you cannot define the body of intrinsic functions. Intrinsic
5325 functions may only be used in call or invoke instructions: it is illegal to
5326 take the address of an intrinsic function. Additionally, because intrinsic
5327 functions are part of the LLVM language, it is required if any are added that
5328 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5329
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5330<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5331 family of functions that perform the same operation but on different data
5332 types. Because LLVM can represent over 8 million different integer types,
5333 overloading is used commonly to allow an intrinsic function to operate on any
5334 integer type. One or more of the argument types or the result type can be
5335 overloaded to accept any integer type. Argument types may also be defined as
5336 exactly matching a previous argument's type or the result type. This allows
5337 an intrinsic function which accepts multiple arguments, but needs all of them
5338 to be of the same type, to only be overloaded with respect to a single
5339 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5340
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5341<p>Overloaded intrinsics will have the names of its overloaded argument types
5342 encoded into its function name, each preceded by a period. Only those types
5343 which are overloaded result in a name suffix. Arguments whose type is matched
5344 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5345 can take an integer of any width and returns an integer of exactly the same
5346 integer width. This leads to a family of functions such as
5347 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5348 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5349 suffix is required. Because the argument's type is matched against the return
5350 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5351
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5352<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5353 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5354
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5355</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5356
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5357<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5358<div class="doc_subsection">
5359 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5360</div>
5361
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5362<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5363
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5364<p>Variable argument support is defined in LLVM with
5365 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5366 intrinsic functions. These functions are related to the similarly named
5367 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5368
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5369<p>All of these functions operate on arguments that use a target-specific value
5370 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5371 not define what this type is, so all transformations should be prepared to
5372 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5373
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5374<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5375 instruction and the variable argument handling intrinsic functions are
5376 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5377
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5378<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5379<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5380define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5381 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5382 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5383 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5384 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5385
5386 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5387 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5388
5389 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5390 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5391 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5392 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5393 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5394
5395 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5396 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5397 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5398}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5399
5400declare void @llvm.va_start(i8*)
5401declare void @llvm.va_copy(i8*, i8*)
5402declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5403</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5404</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5405
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5406</div>
5407
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5408<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5409<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5410 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5411</div>
5412
5413
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5414<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5415
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5416<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5417<pre>
5418 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5419</pre>
5420
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5421<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5422<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5423 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5424
5425<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5426<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5427
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5428<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5429<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5430 macro available in C. In a target-dependent way, it initializes
5431 the <tt>va_list</tt> element to which the argument points, so that the next
5432 call to <tt>va_arg</tt> will produce the first variable argument passed to
5433 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5434 need to know the last argument of the function as the compiler can figure
5435 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5436
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5437</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5438
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5439<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5440<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5441 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5442</div>
5443
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5444<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5445
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5446<h5>Syntax:</h5>
5447<pre>
5448 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5449</pre>
5450
5451<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5452<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5453 which has been initialized previously
5454 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5455 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5456
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5457<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5458<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5459
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5460<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5461<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5462 macro available in C. In a target-dependent way, it destroys
5463 the <tt>va_list</tt> element to which the argument points. Calls
5464 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5465 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5466 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5467
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5468</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5469
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5470<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5471<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5472 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5473</div>
5474
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5475<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5476
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5477<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5478<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5479 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5480</pre>
5481
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5482<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5483<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5484 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5485
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5486<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5487<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5488 The second argument is a pointer to a <tt>va_list</tt> element to copy
5489 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5490
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5491<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5492<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5493 macro available in C. In a target-dependent way, it copies the
5494 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5495 element. This intrinsic is necessary because
5496 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5497 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5498
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5499</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5500
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5501<!-- ======================================================================= -->
5502<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5503 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5504</div>
5505
5506<div class="doc_text">
5507
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5508<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5509Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5510intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5511roots on the stack</a>, as well as garbage collector implementations that
5512require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5513barriers. Front-ends for type-safe garbage collected languages should generate
5514these intrinsics to make use of the LLVM garbage collectors. For more details,
5515see <a href="GarbageCollection.html">Accurate Garbage Collection with
5516LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5518<p>The garbage collection intrinsics only operate on objects in the generic
5519 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5520
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5521</div>
5522
5523<!-- _______________________________________________________________________ -->
5524<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5525 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5526</div>
5527
5528<div class="doc_text">
5529
5530<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5531<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5532 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5533</pre>
5534
5535<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5536<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5538
5539<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5540<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5541 root pointer. The second pointer (which must be either a constant or a
5542 global value address) contains the meta-data to be associated with the
5543 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5544
5545<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5546<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5547 location. At compile-time, the code generator generates information to allow
5548 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5549 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5550 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5551
5552</div>
5553
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5554<!-- _______________________________________________________________________ -->
5555<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5556 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5557</div>
5558
5559<div class="doc_text">
5560
5561<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5562<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5563 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5564</pre>
5565
5566<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5567<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5568 locations, allowing garbage collector implementations that require read
5569 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5570
5571<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5572<p>The second argument is the address to read from, which should be an address
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5573 allocated from the garbage collector. The first object is a pointer to the
5574 start of the referenced object, if needed by the language runtime (otherwise
5575 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5576
5577<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5578<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5579 instruction, but may be replaced with substantially more complex code by the
5580 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5581 may only be used in a function which <a href="#gc">specifies a GC
5582 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5583
5584</div>
5585
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5586<!-- _______________________________________________________________________ -->
5587<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5588 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5589</div>
5590
5591<div class="doc_text">
5592
5593<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5594<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5595 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5596</pre>
5597
5598<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5599<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5600 locations, allowing garbage collector implementations that require write
5601 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5602
5603<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5604<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5605 object to store it to, and the third is the address of the field of Obj to
5606 store to. If the runtime does not require a pointer to the object, Obj may
5607 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5608
5609<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5610<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5611 instruction, but may be replaced with substantially more complex code by the
5612 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5613 may only be used in a function which <a href="#gc">specifies a GC
5614 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5615
5616</div>
5617
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5618<!-- ======================================================================= -->
5619<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5620 <a name="int_codegen">Code Generator Intrinsics</a>
5621</div>
5622
5623<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5624
5625<p>These intrinsics are provided by LLVM to expose special features that may
5626 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5627
5628</div>
5629
5630<!-- _______________________________________________________________________ -->
5631<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5632 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5633</div>
5634
5635<div class="doc_text">
5636
5637<h5>Syntax:</h5>
5638<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5639 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5640</pre>
5641
5642<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5643<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5644 target-specific value indicating the return address of the current function
5645 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5646
5647<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5648<p>The argument to this intrinsic indicates which function to return the address
5649 for. Zero indicates the calling function, one indicates its caller, etc.
5650 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5651
5652<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5653<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5654 indicating the return address of the specified call frame, or zero if it
5655 cannot be identified. The value returned by this intrinsic is likely to be
5656 incorrect or 0 for arguments other than zero, so it should only be used for
5657 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5658
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5659<p>Note that calling this intrinsic does not prevent function inlining or other
5660 aggressive transformations, so the value returned may not be that of the
5661 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5662
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5663</div>
5664
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5665<!-- _______________________________________________________________________ -->
5666<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5667 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5668</div>
5669
5670<div class="doc_text">
5671
5672<h5>Syntax:</h5>
5673<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5674 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5675</pre>
5676
5677<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5678<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5679 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5680
5681<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5682<p>The argument to this intrinsic indicates which function to return the frame
5683 pointer for. Zero indicates the calling function, one indicates its caller,
5684 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5685
5686<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5687<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5688 indicating the frame address of the specified call frame, or zero if it
5689 cannot be identified. The value returned by this intrinsic is likely to be
5690 incorrect or 0 for arguments other than zero, so it should only be used for
5691 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5692
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5693<p>Note that calling this intrinsic does not prevent function inlining or other
5694 aggressive transformations, so the value returned may not be that of the
5695 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5696
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5697</div>
5698
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5699<!-- _______________________________________________________________________ -->
5700<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5701 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5702</div>
5703
5704<div class="doc_text">
5705
5706<h5>Syntax:</h5>
5707<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5708 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5709</pre>
5710
5711<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5712<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5713 of the function stack, for use
5714 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5715 useful for implementing language features like scoped automatic variable
5716 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5717
5718<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5719<p>This intrinsic returns a opaque pointer value that can be passed
5720 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5721 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5722 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5723 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5724 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5725 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5726
5727</div>
5728
5729<!-- _______________________________________________________________________ -->
5730<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5731 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5732</div>
5733
5734<div class="doc_text">
5735
5736<h5>Syntax:</h5>
5737<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5738 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5739</pre>
5740
5741<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5742<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5743 the function stack to the state it was in when the
5744 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5745 executed. This is useful for implementing language features like scoped
5746 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5747
5748<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5749<p>See the description
5750 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5751
5752</div>
5753
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5754<!-- _______________________________________________________________________ -->
5755<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5756 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5757</div>
5758
5759<div class="doc_text">
5760
5761<h5>Syntax:</h5>
5762<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5763 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5764</pre>
5765
5766<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5767<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5768 insert a prefetch instruction if supported; otherwise, it is a noop.
5769 Prefetches have no effect on the behavior of the program but can change its
5770 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5771
5772<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5773<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5774 specifier determining if the fetch should be for a read (0) or write (1),
5775 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5776 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5777 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5778
5779<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5780<p>This intrinsic does not modify the behavior of the program. In particular,
5781 prefetches cannot trap and do not produce a value. On targets that support
5782 this intrinsic, the prefetch can provide hints to the processor cache for
5783 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5784
5785</div>
5786
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5787<!-- _______________________________________________________________________ -->
5788<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5789 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5790</div>
5791
5792<div class="doc_text">
5793
5794<h5>Syntax:</h5>
5795<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5796 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5797</pre>
5798
5799<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5800<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5801 Counter (PC) in a region of code to simulators and other tools. The method
5802 is target specific, but it is expected that the marker will use exported
5803 symbols to transmit the PC of the marker. The marker makes no guarantees
5804 that it will remain with any specific instruction after optimizations. It is
5805 possible that the presence of a marker will inhibit optimizations. The
5806 intended use is to be inserted after optimizations to allow correlations of
5807 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5808
5809<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5810<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5811
5812<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5813<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5814 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5815
5816</div>
5817
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5818<!-- _______________________________________________________________________ -->
5819<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5820 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5821</div>
5822
5823<div class="doc_text">
5824
5825<h5>Syntax:</h5>
5826<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5827 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5828</pre>
5829
5830<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5831<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5832 counter register (or similar low latency, high accuracy clocks) on those
5833 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5834 should map to RPCC. As the backing counters overflow quickly (on the order
5835 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5836
5837<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5838<p>When directly supported, reading the cycle counter should not modify any
5839 memory. Implementations are allowed to either return a application specific
5840 value or a system wide value. On backends without support, this is lowered
5841 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5842
5843</div>
5844
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5845<!-- ======================================================================= -->
5846<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5847 <a name="int_libc">Standard C Library Intrinsics</a>
5848</div>
5849
5850<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5851
5852<p>LLVM provides intrinsics for a few important standard C library functions.
5853 These intrinsics allow source-language front-ends to pass information about
5854 the alignment of the pointer arguments to the code generator, providing
5855 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5856
5857</div>
5858
5859<!-- _______________________________________________________________________ -->
5860<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5861 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5862</div>
5863
5864<div class="doc_text">
5865
5866<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5867<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5868 integer bit width. Not all targets support all bit widths however.</p>
5869
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5870<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5871 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5872 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5873 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5874 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5875 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5876 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5877 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5878 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5879</pre>
5880
5881<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5882<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5883 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5884
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5885<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5886 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5887
5888<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5889<p>The first argument is a pointer to the destination, the second is a pointer
5890 to the source. The third argument is an integer argument specifying the
5891 number of bytes to copy, and the fourth argument is the alignment of the
5892 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5893
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5894<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5895 then the caller guarantees that both the source and destination pointers are
5896 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5897
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5898<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5899<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5900 source location to the destination location, which are not allowed to
5901 overlap. It copies "len" bytes of memory over. If the argument is known to
5902 be aligned to some boundary, this can be specified as the fourth argument,
5903 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5904
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5905</div>
5906
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5907<!-- _______________________________________________________________________ -->
5908<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5909 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5910</div>
5911
5912<div class="doc_text">
5913
5914<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5915<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5916 width. Not all targets support all bit widths however.</p>
5917
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5918<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5919 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5920 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5921 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5922 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5923 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5924 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5925 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5926 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5927</pre>
5928
5929<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5930<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5931 source location to the destination location. It is similar to the
5932 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5933 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5934
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5935<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5936 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5937
5938<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5939<p>The first argument is a pointer to the destination, the second is a pointer
5940 to the source. The third argument is an integer argument specifying the
5941 number of bytes to copy, and the fourth argument is the alignment of the
5942 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5943
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5944<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5945 then the caller guarantees that the source and destination pointers are
5946 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5947
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5948<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5949<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5950 source location to the destination location, which may overlap. It copies
5951 "len" bytes of memory over. If the argument is known to be aligned to some
5952 boundary, this can be specified as the fourth argument, otherwise it should
5953 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5954
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5955</div>
5956
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5957<!-- _______________________________________________________________________ -->
5958<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5959 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5960</div>
5961
5962<div class="doc_text">
5963
5964<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5965<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5966 width. Not all targets support all bit widths however.</p>
5967
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5968<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5969 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5970 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5971 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5972 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5973 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5974 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5975 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5976 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5977</pre>
5978
5979<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5980<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5981 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5982
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5983<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5984 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5985
5986<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5987<p>The first argument is a pointer to the destination to fill, the second is the
5988 byte value to fill it with, the third argument is an integer argument
5989 specifying the number of bytes to fill, and the fourth argument is the known
5990 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5991
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5992<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5993 then the caller guarantees that the destination pointer is aligned to that
5994 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5995
5996<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5997<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5998 at the destination location. If the argument is known to be aligned to some
5999 boundary, this can be specified as the fourth argument, otherwise it should
6000 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6001
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6002</div>
6003
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6004<!-- _______________________________________________________________________ -->
6005<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6006 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6007</div>
6008
6009<div class="doc_text">
6010
6011<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6012<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6013 floating point or vector of floating point type. Not all targets support all
6014 types however.</p>
6015
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6016<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6017 declare float @llvm.sqrt.f32(float %Val)
6018 declare double @llvm.sqrt.f64(double %Val)
6019 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6020 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6021 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6022</pre>
6023
6024<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6025<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6026 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6027 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6028 behavior for negative numbers other than -0.0 (which allows for better
6029 optimization, because there is no need to worry about errno being
6030 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6031
6032<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6033<p>The argument and return value are floating point numbers of the same
6034 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6035
6036<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6037<p>This function returns the sqrt of the specified operand if it is a
6038 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6039
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6040</div>
6041
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6042<!-- _______________________________________________________________________ -->
6043<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6044 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6045</div>
6046
6047<div class="doc_text">
6048
6049<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6050<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6051 floating point or vector of floating point type. Not all targets support all
6052 types however.</p>
6053
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6054<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6055 declare float @llvm.powi.f32(float %Val, i32 %power)
6056 declare double @llvm.powi.f64(double %Val, i32 %power)
6057 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6058 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6059 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6060</pre>
6061
6062<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6063<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6064 specified (positive or negative) power. The order of evaluation of
6065 multiplications is not defined. When a vector of floating point type is
6066 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6067
6068<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6069<p>The second argument is an integer power, and the first is a value to raise to
6070 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6071
6072<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6073<p>This function returns the first value raised to the second power with an
6074 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6075
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6076</div>
6077
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6078<!-- _______________________________________________________________________ -->
6079<div class="doc_subsubsection">
6080 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
6081</div>
6082
6083<div class="doc_text">
6084
6085<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6086<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6087 floating point or vector of floating point type. Not all targets support all
6088 types however.</p>
6089
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6090<pre>
6091 declare float @llvm.sin.f32(float %Val)
6092 declare double @llvm.sin.f64(double %Val)
6093 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6094 declare fp128 @llvm.sin.f128(fp128 %Val)
6095 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6096</pre>
6097
6098<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6099<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6100
6101<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6102<p>The argument and return value are floating point numbers of the same
6103 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6104
6105<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6106<p>This function returns the sine of the specified operand, returning the same
6107 values as the libm <tt>sin</tt> functions would, and handles error conditions
6108 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6109
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6110</div>
6111
6112<!-- _______________________________________________________________________ -->
6113<div class="doc_subsubsection">
6114 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6115</div>
6116
6117<div class="doc_text">
6118
6119<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6120<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6121 floating point or vector of floating point type. Not all targets support all
6122 types however.</p>
6123
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6124<pre>
6125 declare float @llvm.cos.f32(float %Val)
6126 declare double @llvm.cos.f64(double %Val)
6127 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6128 declare fp128 @llvm.cos.f128(fp128 %Val)
6129 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6130</pre>
6131
6132<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6133<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6134
6135<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6136<p>The argument and return value are floating point numbers of the same
6137 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6138
6139<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6140<p>This function returns the cosine of the specified operand, returning the same
6141 values as the libm <tt>cos</tt> functions would, and handles error conditions
6142 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6143
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6144</div>
6145
6146<!-- _______________________________________________________________________ -->
6147<div class="doc_subsubsection">
6148 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6149</div>
6150
6151<div class="doc_text">
6152
6153<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6154<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6155 floating point or vector of floating point type. Not all targets support all
6156 types however.</p>
6157
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6158<pre>
6159 declare float @llvm.pow.f32(float %Val, float %Power)
6160 declare double @llvm.pow.f64(double %Val, double %Power)
6161 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6162 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6163 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6164</pre>
6165
6166<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6167<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6168 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6169
6170<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6171<p>The second argument is a floating point power, and the first is a value to
6172 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6173
6174<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6175<p>This function returns the first value raised to the second power, returning
6176 the same values as the libm <tt>pow</tt> functions would, and handles error
6177 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6178
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6179</div>
6180
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6181<!-- ======================================================================= -->
6182<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6183 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6184</div>
6185
6186<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6187
6188<p>LLVM provides intrinsics for a few important bit manipulation operations.
6189 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6190
6191</div>
6192
6193<!-- _______________________________________________________________________ -->
6194<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6195 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6196</div>
6197
6198<div class="doc_text">
6199
6200<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6201<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6202 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6203
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6204<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6205 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6206 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6207 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6208</pre>
6209
6210<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6211<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6212 values with an even number of bytes (positive multiple of 16 bits). These
6213 are useful for performing operations on data that is not in the target's
6214 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6215
6216<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6217<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6218 and low byte of the input i16 swapped. Similarly,
6219 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6220 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6221 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6222 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6223 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6224 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6225
6226</div>
6227
6228<!-- _______________________________________________________________________ -->
6229<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6230 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6231</div>
6232
6233<div class="doc_text">
6234
6235<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6236<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6237 width. Not all targets support all bit widths however.</p>
6238
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6239<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6240 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6241 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6242 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6243 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6244 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6245</pre>
6246
6247<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6248<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6249 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6250
6251<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6252<p>The only argument is the value to be counted. The argument may be of any
6253 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6254
6255<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6256<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6257
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6258</div>
6259
6260<!-- _______________________________________________________________________ -->
6261<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6262 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6263</div>
6264
6265<div class="doc_text">
6266
6267<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6268<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6269 integer bit width. Not all targets support all bit widths however.</p>
6270
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6271<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6272 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6273 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6274 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6275 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6276 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6277</pre>
6278
6279<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6280<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6281 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6282
6283<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6284<p>The only argument is the value to be counted. The argument may be of any
6285 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6286
6287<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6288<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6289 zeros in a variable. If the src == 0 then the result is the size in bits of
6290 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6291
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6292</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6293
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6294<!-- _______________________________________________________________________ -->
6295<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6296 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6297</div>
6298
6299<div class="doc_text">
6300
6301<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6302<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6303 integer bit width. Not all targets support all bit widths however.</p>
6304
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6305<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6306 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6307 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6308 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6309 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6310 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6311</pre>
6312
6313<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6314<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6315 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6316
6317<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6318<p>The only argument is the value to be counted. The argument may be of any
6319 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6320
6321<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6322<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6323 zeros in a variable. If the src == 0 then the result is the size in bits of
6324 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6325
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6326</div>
6327
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6328<!-- ======================================================================= -->
6329<div class="doc_subsection">
6330 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6331</div>
6332
6333<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6334
6335<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6336
6337</div>
6338
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6339<!-- _______________________________________________________________________ -->
6340<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6341 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6342</div>
6343
6344<div class="doc_text">
6345
6346<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6347<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6348 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6349
6350<pre>
6351 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6352 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6353 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6354</pre>
6355
6356<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6357<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6358 a signed addition of the two arguments, and indicate whether an overflow
6359 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6360
6361<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6362<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6363 be of integer types of any bit width, but they must have the same bit
6364 width. The second element of the result structure must be of
6365 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6366 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6367
6368<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6369<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6370 a signed addition of the two variables. They return a structure &mdash; the
6371 first element of which is the signed summation, and the second element of
6372 which is a bit specifying if the signed summation resulted in an
6373 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6374
6375<h5>Examples:</h5>
6376<pre>
6377 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6378 %sum = extractvalue {i32, i1} %res, 0
6379 %obit = extractvalue {i32, i1} %res, 1
6380 br i1 %obit, label %overflow, label %normal
6381</pre>
6382
6383</div>
6384
6385<!-- _______________________________________________________________________ -->
6386<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6387 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6388</div>
6389
6390<div class="doc_text">
6391
6392<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6393<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6394 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6395
6396<pre>
6397 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6398 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6399 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6400</pre>
6401
6402<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6403<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6404 an unsigned addition of the two arguments, and indicate whether a carry
6405 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6406
6407<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6408<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6409 be of integer types of any bit width, but they must have the same bit
6410 width. The second element of the result structure must be of
6411 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6412 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6413
6414<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6415<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6416 an unsigned addition of the two arguments. They return a structure &mdash;
6417 the first element of which is the sum, and the second element of which is a
6418 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6419
6420<h5>Examples:</h5>
6421<pre>
6422 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6423 %sum = extractvalue {i32, i1} %res, 0
6424 %obit = extractvalue {i32, i1} %res, 1
6425 br i1 %obit, label %carry, label %normal
6426</pre>
6427
6428</div>
6429
6430<!-- _______________________________________________________________________ -->
6431<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6432 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6433</div>
6434
6435<div class="doc_text">
6436
6437<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6438<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6439 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6440
6441<pre>
6442 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6443 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6444 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6445</pre>
6446
6447<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6448<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6449 a signed subtraction of the two arguments, and indicate whether an overflow
6450 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6451
6452<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6453<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6454 be of integer types of any bit width, but they must have the same bit
6455 width. The second element of the result structure must be of
6456 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6457 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6458
6459<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6460<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6461 a signed subtraction of the two arguments. They return a structure &mdash;
6462 the first element of which is the subtraction, and the second element of
6463 which is a bit specifying if the signed subtraction resulted in an
6464 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6465
6466<h5>Examples:</h5>
6467<pre>
6468 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6469 %sum = extractvalue {i32, i1} %res, 0
6470 %obit = extractvalue {i32, i1} %res, 1
6471 br i1 %obit, label %overflow, label %normal
6472</pre>
6473
6474</div>
6475
6476<!-- _______________________________________________________________________ -->
6477<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6478 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6479</div>
6480
6481<div class="doc_text">
6482
6483<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6484<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6485 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6486
6487<pre>
6488 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6489 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6490 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6491</pre>
6492
6493<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6494<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6495 an unsigned subtraction of the two arguments, and indicate whether an
6496 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6497
6498<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6499<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6500 be of integer types of any bit width, but they must have the same bit
6501 width. The second element of the result structure must be of
6502 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6503 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6504
6505<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6506<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6507 an unsigned subtraction of the two arguments. They return a structure &mdash;
6508 the first element of which is the subtraction, and the second element of
6509 which is a bit specifying if the unsigned subtraction resulted in an
6510 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6511
6512<h5>Examples:</h5>
6513<pre>
6514 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6515 %sum = extractvalue {i32, i1} %res, 0
6516 %obit = extractvalue {i32, i1} %res, 1
6517 br i1 %obit, label %overflow, label %normal
6518</pre>
6519
6520</div>
6521
6522<!-- _______________________________________________________________________ -->
6523<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6524 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6525</div>
6526
6527<div class="doc_text">
6528
6529<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6530<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6531 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6532
6533<pre>
6534 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6535 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6536 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6537</pre>
6538
6539<h5>Overview:</h5>
6540
6541<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6542 a signed multiplication of the two arguments, and indicate whether an
6543 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6544
6545<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6546<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6547 be of integer types of any bit width, but they must have the same bit
6548 width. The second element of the result structure must be of
6549 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6550 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6551
6552<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6553<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6554 a signed multiplication of the two arguments. They return a structure &mdash;
6555 the first element of which is the multiplication, and the second element of
6556 which is a bit specifying if the signed multiplication resulted in an
6557 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6558
6559<h5>Examples:</h5>
6560<pre>
6561 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6562 %sum = extractvalue {i32, i1} %res, 0
6563 %obit = extractvalue {i32, i1} %res, 1
6564 br i1 %obit, label %overflow, label %normal
6565</pre>
6566
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6567</div>
6568
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6569<!-- _______________________________________________________________________ -->
6570<div class="doc_subsubsection">
6571 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6572</div>
6573
6574<div class="doc_text">
6575
6576<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6577<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6578 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6579
6580<pre>
6581 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6582 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6583 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6584</pre>
6585
6586<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6587<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6588 a unsigned multiplication of the two arguments, and indicate whether an
6589 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6590
6591<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6592<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6593 be of integer types of any bit width, but they must have the same bit
6594 width. The second element of the result structure must be of
6595 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6596 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6597
6598<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6599<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6600 an unsigned multiplication of the two arguments. They return a structure
6601 &mdash; the first element of which is the multiplication, and the second
6602 element of which is a bit specifying if the unsigned multiplication resulted
6603 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6604
6605<h5>Examples:</h5>
6606<pre>
6607 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6608 %sum = extractvalue {i32, i1} %res, 0
6609 %obit = extractvalue {i32, i1} %res, 1
6610 br i1 %obit, label %overflow, label %normal
6611</pre>
6612
6613</div>
6614
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6615<!-- ======================================================================= -->
6616<div class="doc_subsection">
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6617 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
6618</div>
6619
6620<div class="doc_text">
6621
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame^]6622<p>Half precision floating point is storage-only format. This means that it is
6623 an encoding (typically for density in memory) but typically does not support
6624 computation in the format.</p>
6625
6626<p>This means that you code must first load the half-precision floating point
6627 value as an i16, then convert it to float with <a
6628 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
6629 Computation can then be performed on the float value (including extending to
6630 double etc). When the value is ready to be stored back to memory, this is
6631 done by converting to float if needed, then converting to i16 with
6632 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
6633 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6634</div>
6635
6636<!-- _______________________________________________________________________ -->
6637<div class="doc_subsubsection">
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame^]6638 <a name="int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6639</div>
6640
6641<div class="doc_text">
6642
6643<h5>Syntax:</h5>
6644<pre>
6645 declare i16 @llvm.convert.to.fp16(f32 %a)
6646</pre>
6647
6648<h5>Overview:</h5>
6649<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6650 a conversion from single precision floating point format to half precision
6651 floating point format.</p>
6652
6653<h5>Arguments:</h5>
6654<p>The intrinsic function contains single argument - the value to be
6655 converted.</p>
6656
6657<h5>Semantics:</h5>
6658<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6659 a conversion from single precision floating point format to half precision
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame^]6660 floating point format. The return value is just an <tt>i16</tt> which
6661 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6662
6663<h5>Examples:</h5>
6664<pre>
6665 %res = call i16 @llvm.convert.to.fp16(f32 %a)
6666 store i16 %res, i16* @x, align 2
6667</pre>
6668
6669</div>
6670
6671<!-- _______________________________________________________________________ -->
6672<div class="doc_subsubsection">
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame^]6673 <a name="int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6674</div>
6675
6676<div class="doc_text">
6677
6678<h5>Syntax:</h5>
6679<pre>
6680 declare f32 @llvm.convert.from.fp16(i16 %a)
6681</pre>
6682
6683<h5>Overview:</h5>
6684<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
6685 a conversion from half precision floating point format to single precision
6686 floating point format.</p>
6687
6688<h5>Arguments:</h5>
6689<p>The intrinsic function contains single argument - the value to be
6690 converted.</p>
6691
6692<h5>Semantics:</h5>
6693<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame^]6694 conversion from half single precision floating point format to signgle
6695 precision floating point format. The input half-float value is represented by
6696 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6697
6698<h5>Examples:</h5>
6699<pre>
6700 %a = load i16* @x, align 2
6701 %res = call f32 @llvm.convert.from.fp16(i16 %a)
6702</pre>
6703
6704</div>
6705
6706<!-- ======================================================================= -->
6707<div class="doc_subsection">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6708 <a name="int_debugger">Debugger Intrinsics</a>
6709</div>
6710
6711<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6712
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6713<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6714 prefix), are described in
6715 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6716 Level Debugging</a> document.</p>
6717
6718</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6719
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6720<!-- ======================================================================= -->
6721<div class="doc_subsection">
6722 <a name="int_eh">Exception Handling Intrinsics</a>
6723</div>
6724
6725<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6726
6727<p>The LLVM exception handling intrinsics (which all start with
6728 <tt>llvm.eh.</tt> prefix), are described in
6729 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6730 Handling</a> document.</p>
6731
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6732</div>
6733
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6734<!-- ======================================================================= -->
6735<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6736 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6737</div>
6738
6739<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6740
6741<p>This intrinsic makes it possible to excise one parameter, marked with
6742 the <tt>nest</tt> attribute, from a function. The result is a callable
6743 function pointer lacking the nest parameter - the caller does not need to
6744 provide a value for it. Instead, the value to use is stored in advance in a
6745 "trampoline", a block of memory usually allocated on the stack, which also
6746 contains code to splice the nest value into the argument list. This is used
6747 to implement the GCC nested function address extension.</p>
6748
6749<p>For example, if the function is
6750 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6751 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6752 follows:</p>
6753
6754<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6755<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6756 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6757 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6758 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6759 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6760</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6761</div>
6762
6763<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6764 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6765
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6766</div>
6767
6768<!-- _______________________________________________________________________ -->
6769<div class="doc_subsubsection">
6770 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6771</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6772
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6773<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6774
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6775<h5>Syntax:</h5>
6776<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6777 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6778</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6779
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6780<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6781<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6782 function pointer suitable for executing it.</p>
6783
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6784<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6785<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6786 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6787 sufficiently aligned block of memory; this memory is written to by the
6788 intrinsic. Note that the size and the alignment are target-specific - LLVM
6789 currently provides no portable way of determining them, so a front-end that
6790 generates this intrinsic needs to have some target-specific knowledge.
6791 The <tt>func</tt> argument must hold a function bitcast to
6792 an <tt>i8*</tt>.</p>
6793
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6794<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6795<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6796 dependent code, turning it into a function. A pointer to this function is
6797 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6798 function pointer type</a> before being called. The new function's signature
6799 is the same as that of <tt>func</tt> with any arguments marked with
6800 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6801 is allowed, and it must be of pointer type. Calling the new function is
6802 equivalent to calling <tt>func</tt> with the same argument list, but
6803 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6804 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6805 by <tt>tramp</tt> is modified, then the effect of any later call to the
6806 returned function pointer is undefined.</p>
6807
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6808</div>
6809
6810<!-- ======================================================================= -->
6811<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6812 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6813</div>
6814
6815<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6816
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6817<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6818 hardware constructs for atomic operations and memory synchronization. This
6819 provides an interface to the hardware, not an interface to the programmer. It
6820 is aimed at a low enough level to allow any programming models or APIs
6821 (Application Programming Interfaces) which need atomic behaviors to map
6822 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6823 hardware provides a "universal IR" for source languages, it also provides a
6824 starting point for developing a "universal" atomic operation and
6825 synchronization IR.</p>
6826
6827<p>These do <em>not</em> form an API such as high-level threading libraries,
6828 software transaction memory systems, atomic primitives, and intrinsic
6829 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6830 application libraries. The hardware interface provided by LLVM should allow
6831 a clean implementation of all of these APIs and parallel programming models.
6832 No one model or paradigm should be selected above others unless the hardware
6833 itself ubiquitously does so.</p>
6834
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6835</div>
6836
6837<!-- _______________________________________________________________________ -->
6838<div class="doc_subsubsection">
6839 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6840</div>
6841<div class="doc_text">
6842<h5>Syntax:</h5>
6843<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6844 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 Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6845</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6846
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6847<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6848<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6849 specific pairs of memory access types.</p>
6850
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6851<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6852<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6853 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6854 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6855 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6856
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6857<ul>
6858 <li><tt>ll</tt>: load-load barrier</li>
6859 <li><tt>ls</tt>: load-store barrier</li>
6860 <li><tt>sl</tt>: store-load barrier</li>
6861 <li><tt>ss</tt>: store-store barrier</li>
6862 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6863</ul>
6864
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6865<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6866<p>This intrinsic causes the system to enforce some ordering constraints upon
6867 the loads and stores of the program. This barrier does not
6868 indicate <em>when</em> any events will occur, it only enforces
6869 an <em>order</em> in which they occur. For any of the specified pairs of load
6870 and store operations (f.ex. load-load, or store-load), all of the first
6871 operations preceding the barrier will complete before any of the second
6872 operations succeeding the barrier begin. Specifically the semantics for each
6873 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6874
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6875<ul>
6876 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6877 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6878 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6879 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6880 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6881 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6882 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6883 load after the barrier begins.</li>
6884</ul>
6885
6886<p>These semantics are applied with a logical "and" behavior when more than one
6887 is enabled in a single memory barrier intrinsic.</p>
6888
6889<p>Backends may implement stronger barriers than those requested when they do
6890 not support as fine grained a barrier as requested. Some architectures do
6891 not need all types of barriers and on such architectures, these become
6892 noops.</p>
6893
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6894<h5>Example:</h5>
6895<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6896%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6897%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6898 store i32 4, %ptr
6899
6900%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6901 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6902 <i>; guarantee the above finishes</i>
6903 store i32 8, %ptr <i>; before this begins</i>
6904</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6905
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6906</div>
6907
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6908<!-- _______________________________________________________________________ -->
6909<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6910 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6911</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6912
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6913<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6914
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6915<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6916<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6917 any integer bit width and for different address spaces. Not all targets
6918 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6919
6920<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6921 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6922 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6923 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6924 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6925</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6926
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6927<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6928<p>This loads a value in memory and compares it to a given value. If they are
6929 equal, it stores a new value into the memory.</p>
6930
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6931<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6932<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6933 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6934 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6935 this integer type. While any bit width integer may be used, targets may only
6936 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6937
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6938<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6939<p>This entire intrinsic must be executed atomically. It first loads the value
6940 in memory pointed to by <tt>ptr</tt> and compares it with the
6941 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6942 memory. The loaded value is yielded in all cases. This provides the
6943 equivalent of an atomic compare-and-swap operation within the SSA
6944 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6945
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6946<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6947<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6948%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6949%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6950 store i32 4, %ptr
6951
6952%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6953%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6954 <i>; yields {i32}:result1 = 4</i>
6955%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6956%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6957
6958%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6959%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6960 <i>; yields {i32}:result2 = 8</i>
6961%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6962
6963%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6964</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6965
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6966</div>
6967
6968<!-- _______________________________________________________________________ -->
6969<div class="doc_subsubsection">
6970 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6971</div>
6972<div class="doc_text">
6973<h5>Syntax:</h5>
6974
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6975<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6976 integer bit width. Not all targets support all bit widths however.</p>
6977
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6978<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6979 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6980 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6981 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6982 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6983</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6984
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6985<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6986<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6987 the value from memory. It then stores the value in <tt>val</tt> in the memory
6988 at <tt>ptr</tt>.</p>
6989
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6990<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6991<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6992 the <tt>val</tt> argument and the result must be integers of the same bit
6993 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6994 integer type. The targets may only lower integer representations they
6995 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6996
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6997<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6998<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6999 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7000 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7001
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7002<h5>Examples:</h5>
7003<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7004%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7005%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7006 store i32 4, %ptr
7007
7008%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7009%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7010 <i>; yields {i32}:result1 = 4</i>
7011%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7012%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7013
7014%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7015%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7016 <i>; yields {i32}:result2 = 8</i>
7017
7018%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7019%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7020</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7021
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7022</div>
7023
7024<!-- _______________________________________________________________________ -->
7025<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7026 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7027
7028</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7029
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7030<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7031
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7032<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7033<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7034 any integer bit width. Not all targets support all bit widths however.</p>
7035
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7036<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7037 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7038 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7039 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7040 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7041</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7042
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7043<h5>Overview:</h5>
7044<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7045 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7046
7047<h5>Arguments:</h5>
7048<p>The intrinsic takes two arguments, the first a pointer to an integer value
7049 and the second an integer value. The result is also an integer value. These
7050 integer types can have any bit width, but they must all have the same bit
7051 width. The targets may only lower integer representations they support.</p>
7052
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7053<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7054<p>This intrinsic does a series of operations atomically. It first loads the
7055 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7056 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7057
7058<h5>Examples:</h5>
7059<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7060%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7061%ptr = bitcast i8* %mallocP to i32*
7062 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7063%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7064 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7065%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7066 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7067%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7068 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7069%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7070</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7071
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7072</div>
7073
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7074<!-- _______________________________________________________________________ -->
7075<div class="doc_subsubsection">
7076 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
7077
7078</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7079
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7080<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7081
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7082<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7083<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7084 any integer bit width and for different address spaces. Not all targets
7085 support all bit widths however.</p>
7086
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7087<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7088 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7089 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7090 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7091 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7092</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7093
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7094<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7095<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7096 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7097
7098<h5>Arguments:</h5>
7099<p>The intrinsic takes two arguments, the first a pointer to an integer value
7100 and the second an integer value. The result is also an integer value. These
7101 integer types can have any bit width, but they must all have the same bit
7102 width. The targets may only lower integer representations they support.</p>
7103
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7104<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7105<p>This intrinsic does a series of operations atomically. It first loads the
7106 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7107 result to <tt>ptr</tt>. It yields the original value stored
7108 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7109
7110<h5>Examples:</h5>
7111<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7112%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7113%ptr = bitcast i8* %mallocP to i32*
7114 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7115%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7116 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7117%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7118 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7119%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7120 <i>; yields {i32}:result3 = 2</i>
7121%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7122</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7123
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7124</div>
7125
7126<!-- _______________________________________________________________________ -->
7127<div class="doc_subsubsection">
7128 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
7129 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
7130 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
7131 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7132</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7133
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7134<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7135
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7136<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7137<p>These are overloaded intrinsics. You can
7138 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7139 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7140 bit width and for different address spaces. Not all targets support all bit
7141 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7142
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7143<pre>
7144 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7145 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7146 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7147 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7148</pre>
7149
7150<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7151 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7152 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7153 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7154 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7155</pre>
7156
7157<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7158 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7159 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7160 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7161 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7162</pre>
7163
7164<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7165 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7166 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7167 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7168 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7169</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7170
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7171<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7172<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7173 the value stored in memory at <tt>ptr</tt>. It yields the original value
7174 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7175
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7176<h5>Arguments:</h5>
7177<p>These intrinsics take two arguments, the first a pointer to an integer value
7178 and the second an integer value. The result is also an integer value. These
7179 integer types can have any bit width, but they must all have the same bit
7180 width. The targets may only lower integer representations they support.</p>
7181
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7182<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7183<p>These intrinsics does a series of operations atomically. They first load the
7184 value stored at <tt>ptr</tt>. They then do the bitwise
7185 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7186 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7187
7188<h5>Examples:</h5>
7189<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7190%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7191%ptr = bitcast i8* %mallocP to i32*
7192 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7193%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7194 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7195%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7196 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7197%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7198 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7199%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7200 <i>; yields {i32}:result3 = FF</i>
7201%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7202</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7203
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7204</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7205
7206<!-- _______________________________________________________________________ -->
7207<div class="doc_subsubsection">
7208 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7209 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7210 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7211 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7212</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7213
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7214<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7215
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7216<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7217<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7218 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7219 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7220 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7221
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7222<pre>
7223 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7224 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7225 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7226 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7227</pre>
7228
7229<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7230 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7231 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7232 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7233 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7234</pre>
7235
7236<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7237 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7238 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7239 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7240 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7241</pre>
7242
7243<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7244 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7245 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7246 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7247 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7248</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7249
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7250<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7251<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7252 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7253 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7254
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7255<h5>Arguments:</h5>
7256<p>These intrinsics take two arguments, the first a pointer to an integer value
7257 and the second an integer value. The result is also an integer value. These
7258 integer types can have any bit width, but they must all have the same bit
7259 width. The targets may only lower integer representations they support.</p>
7260
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7261<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7262<p>These intrinsics does a series of operations atomically. They first load the
7263 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7264 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7265 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7266
7267<h5>Examples:</h5>
7268<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7269%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7270%ptr = bitcast i8* %mallocP to i32*
7271 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7272%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7273 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7274%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7275 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7276%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7277 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7278%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7279 <i>; yields {i32}:result3 = 8</i>
7280%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7281</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7282
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7283</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7284
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7285
7286<!-- ======================================================================= -->
7287<div class="doc_subsection">
7288 <a name="int_memorymarkers">Memory Use Markers</a>
7289</div>
7290
7291<div class="doc_text">
7292
7293<p>This class of intrinsics exists to information about the lifetime of memory
7294 objects and ranges where variables are immutable.</p>
7295
7296</div>
7297
7298<!-- _______________________________________________________________________ -->
7299<div class="doc_subsubsection">
7300 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7301</div>
7302
7303<div class="doc_text">
7304
7305<h5>Syntax:</h5>
7306<pre>
7307 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7308</pre>
7309
7310<h5>Overview:</h5>
7311<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7312 object's lifetime.</p>
7313
7314<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7315<p>The first argument is a constant integer representing the size of the
7316 object, or -1 if it is variable sized. The second argument is a pointer to
7317 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7318
7319<h5>Semantics:</h5>
7320<p>This intrinsic indicates that before this point in the code, the value of the
7321 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewyckyd20fd592009-10-27 16:56:58 +0000[diff] [blame]7322 never be used and has an undefined value. A load from the pointer that
7323 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7324 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7325
7326</div>
7327
7328<!-- _______________________________________________________________________ -->
7329<div class="doc_subsubsection">
7330 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7331</div>
7332
7333<div class="doc_text">
7334
7335<h5>Syntax:</h5>
7336<pre>
7337 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7338</pre>
7339
7340<h5>Overview:</h5>
7341<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7342 object's lifetime.</p>
7343
7344<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7345<p>The first argument is a constant integer representing the size of the
7346 object, or -1 if it is variable sized. The second argument is a pointer to
7347 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7348
7349<h5>Semantics:</h5>
7350<p>This intrinsic indicates that after this point in the code, the value of the
7351 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7352 never be used and has an undefined value. Any stores into the memory object
7353 following this intrinsic may be removed as dead.
7354
7355</div>
7356
7357<!-- _______________________________________________________________________ -->
7358<div class="doc_subsubsection">
7359 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7360</div>
7361
7362<div class="doc_text">
7363
7364<h5>Syntax:</h5>
7365<pre>
7366 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7367</pre>
7368
7369<h5>Overview:</h5>
7370<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7371 a memory object will not change.</p>
7372
7373<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7374<p>The first argument is a constant integer representing the size of the
7375 object, or -1 if it is variable sized. The second argument is a pointer to
7376 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7377
7378<h5>Semantics:</h5>
7379<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7380 the return value, the referenced memory location is constant and
7381 unchanging.</p>
7382
7383</div>
7384
7385<!-- _______________________________________________________________________ -->
7386<div class="doc_subsubsection">
7387 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7388</div>
7389
7390<div class="doc_text">
7391
7392<h5>Syntax:</h5>
7393<pre>
7394 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7395</pre>
7396
7397<h5>Overview:</h5>
7398<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7399 a memory object are mutable.</p>
7400
7401<h5>Arguments:</h5>
7402<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7403 The second argument is a constant integer representing the size of the
7404 object, or -1 if it is variable sized and the third argument is a pointer
7405 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7406
7407<h5>Semantics:</h5>
7408<p>This intrinsic indicates that the memory is mutable again.</p>
7409
7410</div>
7411
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7412<!-- ======================================================================= -->
7413<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7414 <a name="int_general">General Intrinsics</a>
7415</div>
7416
7417<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7418
7419<p>This class of intrinsics is designed to be generic and has no specific
7420 purpose.</p>
7421
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7422</div>
7423
7424<!-- _______________________________________________________________________ -->
7425<div class="doc_subsubsection">
7426 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7427</div>
7428
7429<div class="doc_text">
7430
7431<h5>Syntax:</h5>
7432<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]7433 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7434</pre>
7435
7436<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7437<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7438
7439<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7440<p>The first argument is a pointer to a value, the second is a pointer to a
7441 global string, the third is a pointer to a global string which is the source
7442 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7443
7444<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7445<p>This intrinsic allows annotation of local variables with arbitrary strings.
7446 This can be useful for special purpose optimizations that want to look for
7447 these annotations. These have no other defined use, they are ignored by code
7448 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7449
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7450</div>
7451
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7452<!-- _______________________________________________________________________ -->
7453<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7454 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7455</div>
7456
7457<div class="doc_text">
7458
7459<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7460<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7461 any integer bit width.</p>
7462
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7463<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]7464 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7465 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7466 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7467 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7468 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7469</pre>
7470
7471<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7472<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7473
7474<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7475<p>The first argument is an integer value (result of some expression), the
7476 second is a pointer to a global string, the third is a pointer to a global
7477 string which is the source file name, and the last argument is the line
7478 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7479
7480<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7481<p>This intrinsic allows annotations to be put on arbitrary expressions with
7482 arbitrary strings. This can be useful for special purpose optimizations that
7483 want to look for these annotations. These have no other defined use, they
7484 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7485
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7486</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7487
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7488<!-- _______________________________________________________________________ -->
7489<div class="doc_subsubsection">
7490 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7491</div>
7492
7493<div class="doc_text">
7494
7495<h5>Syntax:</h5>
7496<pre>
7497 declare void @llvm.trap()
7498</pre>
7499
7500<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7501<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7502
7503<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7504<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7505
7506<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7507<p>This intrinsics is lowered to the target dependent trap instruction. If the
7508 target does not have a trap instruction, this intrinsic will be lowered to
7509 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7510
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7511</div>
7512
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7513<!-- _______________________________________________________________________ -->
7514<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7515 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7516</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7517
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7518<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7519
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7520<h5>Syntax:</h5>
7521<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7522 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7523</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7524
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7525<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7526<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7527 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7528 ensure that it is placed on the stack before local variables.</p>
7529
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7530<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7531<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7532 arguments. The first argument is the value loaded from the stack
7533 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7534 that has enough space to hold the value of the guard.</p>
7535
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7536<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7537<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7538 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7539 stack. This is to ensure that if a local variable on the stack is
7540 overwritten, it will destroy the value of the guard. When the function exits,
7541 the guard on the stack is checked against the original guard. If they're
7542 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7543 function.</p>
7544
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7545</div>
7546
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7547<!-- _______________________________________________________________________ -->
7548<div class="doc_subsubsection">
7549 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7550</div>
7551
7552<div class="doc_text">
7553
7554<h5>Syntax:</h5>
7555<pre>
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7556 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7557 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7558</pre>
7559
7560<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7561<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopher3070e162010-01-08 21:42:39 +0000[diff] [blame]7562 to the optimizers to discover at compile time either a) when an
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7563 operation like memcpy will either overflow a buffer that corresponds to
7564 an object, or b) to determine that a runtime check for overflow isn't
7565 necessary. An object in this context means an allocation of a
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7566 specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7567
7568<h5>Arguments:</h5>
7569<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7570 argument is a pointer to or into the <tt>object</tt>. The second argument
7571 is a boolean 0 or 1. This argument determines whether you want the
7572 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7573 1, variables are not allowed.</p>
7574
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7575<h5>Semantics:</h5>
7576<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7577 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7578 (depending on the <tt>type</tt> argument if the size cannot be determined
7579 at compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7580
7581</div>
7582
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7583<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7584<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7585<address>
7586 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7587 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7588 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7589 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7590
7591 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]7592 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7593 Last modified: $Date$
7594</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]7595
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]7596</body>
7597</html>