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gerrit-public.fairphone.software / toolchain / llvm-project / 3ef668c27ae05a20329f406e58bfe74af507ce4c / . / 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">
8 <meta name="description"
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>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]58 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]59 </ol>
60 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]61 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]62 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]63 <li><a href="#simpleconstants">Simple Constants</a></li>
64 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
65 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
66 <li><a href="#undefvalues">Undefined Values</a></li>
67 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]68 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]69 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]70 <li><a href="#othervalues">Other Values</a>
71 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]72 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]73 </ol>
74 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]75 <li><a href="#instref">Instruction Reference</a>
76 <ol>
77 <li><a href="#terminators">Terminator Instructions</a>
78 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]79 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
80 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
82 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]84 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]87 <li><a href="#binaryops">Binary Operations</a>
88 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]89 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
90 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
91 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]92 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
93 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
94 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]95 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
96 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
97 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]98 </ol>
99 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]100 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
101 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]102 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
103 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
104 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]106 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]107 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]110 <li><a href="#vectorops">Vector Operations</a>
111 <ol>
112 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
113 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
114 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]115 </ol>
116 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]117 <li><a href="#aggregateops">Aggregate Operations</a>
118 <ol>
119 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
120 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
121 </ol>
122 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]123 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]124 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
126 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
127 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]128 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
129 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
130 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]133 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]134 <ol>
135 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]140 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
141 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
142 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
143 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]144 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
145 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]146 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]147 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]148 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]149 <li><a href="#otherops">Other Operations</a>
150 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]151 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
152 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]153 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
154 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]156 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]157 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]158 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]161 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]162 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]163 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]164 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]165 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
166 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]167 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
169 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]170 </ol>
171 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]172 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
173 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]174 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
176 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]177 </ol>
178 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]179 <li><a href="#int_codegen">Code Generator Intrinsics</a>
180 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]181 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
183 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
184 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
185 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
186 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
187 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]188 </ol>
189 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]190 <li><a href="#int_libc">Standard C Library Intrinsics</a>
191 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]192 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]197 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
199 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]200 </ol>
201 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]202 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]203 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]204 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]205 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]208 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
209 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]210 </ol>
211 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]212 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
213 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]214 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
215 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
216 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
217 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
218 <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]219 <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]220 </ol>
221 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]222 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]223 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]224 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]225 <ol>
226 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]227 </ol>
228 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]229 <li><a href="#int_atomics">Atomic intrinsics</a>
230 <ol>
231 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
232 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
233 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
234 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
235 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
236 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
237 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
238 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
239 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
240 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
241 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
242 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
243 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
244 </ol>
245 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]246 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]247 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]248 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]249 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]250 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]251 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]252 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]253 '<tt>llvm.trap</tt>' Intrinsic</a></li>
254 <li><a href="#int_stackprotector">
255 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]256 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]257 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]258 </ol>
259 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]260</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]261
262<div class="doc_author">
263 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
264 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]265</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]266
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]267<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]268<div class="doc_section"> <a name="abstract">Abstract </a></div>
269<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]270
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]271<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]272<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]273LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]274type safety, low-level operations, flexibility, and the capability of
275representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]276representation used throughout all phases of the LLVM compilation
277strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]278</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]279
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]280<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]281<div class="doc_section"> <a name="introduction">Introduction</a> </div>
282<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]283
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]284<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]285
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]286<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]287different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]288representation (suitable for fast loading by a Just-In-Time compiler),
289and as a human readable assembly language representation. This allows
290LLVM to provide a powerful intermediate representation for efficient
291compiler transformations and analysis, while providing a natural means
292to debug and visualize the transformations. The three different forms
293of LLVM are all equivalent. This document describes the human readable
294representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]296<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]297while being expressive, typed, and extensible at the same time. It
298aims to be a "universal IR" of sorts, by being at a low enough level
299that high-level ideas may be cleanly mapped to it (similar to how
300microprocessors are "universal IR's", allowing many source languages to
301be mapped to them). By providing type information, LLVM can be used as
302the target of optimizations: for example, through pointer analysis, it
303can be proven that a C automatic variable is never accessed outside of
304the current function... allowing it to be promoted to a simple SSA
305value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]306
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]307</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]308
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]309<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]310<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]311
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]312<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]313
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]314<p>It is important to note that this document describes 'well formed'
315LLVM assembly language. There is a difference between what the parser
316accepts and what is considered 'well formed'. For example, the
317following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]318
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]319<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]320<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]321%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]322</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]323</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]325<p>...because the definition of <tt>%x</tt> does not dominate all of
326its uses. The LLVM infrastructure provides a verification pass that may
327be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]328automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]329the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]330by the verifier pass indicate bugs in transformation passes or input to
331the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]332</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]333
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]334<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]335
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]336<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]337<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]338<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]339
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]340<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]341
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]342 <p>LLVM identifiers come in two basic types: global and local. Global
343 identifiers (functions, global variables) begin with the @ character. Local
344 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]345 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]346
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]347<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]348 <li>Named values are represented as a string of characters with their prefix.
349 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
350 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]351 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame]352 with quotes. Special characters may be escaped using "\xx" where xx is the
353 ASCII code for the character in hexadecimal. In this way, any character can
354 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]355
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]356 <li>Unnamed values are represented as an unsigned numeric value with their
357 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]358
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]359 <li>Constants, which are described in a <a href="#constants">section about
360 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]361</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]362
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]363<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]364don't need to worry about name clashes with reserved words, and the set of
365reserved words may be expanded in the future without penalty. Additionally,
366unnamed identifiers allow a compiler to quickly come up with a temporary
367variable without having to avoid symbol table conflicts.</p>
368
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]369<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]370languages. There are keywords for different opcodes
371('<tt><a href="#i_add">add</a></tt>',
372 '<tt><a href="#i_bitcast">bitcast</a></tt>',
373 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]374href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]375and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]376none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]377
378<p>Here is an example of LLVM code to multiply the integer variable
379'<tt>%X</tt>' by 8:</p>
380
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]381<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]382
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]383<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]384<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]385%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]386</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]388
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]389<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]390
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]391<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]392<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]393%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]394</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]395</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]396
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]397<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]398
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]400<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]401<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
402<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
403%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]404</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]405</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]406
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]407<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
408important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]410<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]411
412 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
413 line.</li>
414
415 <li>Unnamed temporaries are created when the result of a computation is not
416 assigned to a named value.</li>
417
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]418 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]419
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]422<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]423demonstrating instructions, we will follow an instruction with a comment that
424defines the type and name of value produced. Comments are shown in italic
425text.</p>
426
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]427</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]428
429<!-- *********************************************************************** -->
430<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
431<!-- *********************************************************************** -->
432
433<!-- ======================================================================= -->
434<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
435</div>
436
437<div class="doc_text">
438
439<p>LLVM programs are composed of "Module"s, each of which is a
440translation unit of the input programs. Each module consists of
441functions, global variables, and symbol table entries. Modules may be
442combined together with the LLVM linker, which merges function (and
443global variable) definitions, resolves forward declarations, and merges
444symbol table entries. Here is an example of the "hello world" module:</p>
445
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]446<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]447<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]448<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
449 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]450
451<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]452<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]453
454<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]455define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]456 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]457 %cast210 = <a
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]458 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]459
460 <i>; Call puts function to write out the string to stdout...</i>
461 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]462 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]463 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]464 href="#i_ret">ret</a> i32 0<br>}<br>
465</pre>
466</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]467
468<p>This example is made up of a <a href="#globalvars">global variable</a>
469named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
470function, and a <a href="#functionstructure">function definition</a>
471for "<tt>main</tt>".</p>
472
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]473<p>In general, a module is made up of a list of global values,
474where both functions and global variables are global values. Global values are
475represented by a pointer to a memory location (in this case, a pointer to an
476array of char, and a pointer to a function), and have one of the following <a
477href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]478
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]479</div>
480
481<!-- ======================================================================= -->
482<div class="doc_subsection">
483 <a name="linkage">Linkage Types</a>
484</div>
485
486<div class="doc_text">
487
488<p>
489All Global Variables and Functions have one of the following types of linkage:
490</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
492<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]493
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]494 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
495
496 <dd>Global values with private linkage are only directly accessible by
497 objects in the current module. In particular, linking code into a module with
498 an private global value may cause the private to be renamed as necessary to
499 avoid collisions. Because the symbol is private to the module, all
500 references can be updated. This doesn't show up in any symbol table in the
501 object file.
502 </dd>
503
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]504 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]505
Duncan Sands35e43c12009-01-16 09:29:46 +0000[diff] [blame]506 <dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]507 the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]508 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]509 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]510
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]511 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]512
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]513 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
514 the same name when linkage occurs. This is typically used to implement
515 inline functions, templates, or other code which must be generated in each
516 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
517 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]518 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]519
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
521
522 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
523 linkage, except that unreferenced <tt>common</tt> globals may not be
524 discarded. This is used for globals that may be emitted in multiple
525 translation units, but that are not guaranteed to be emitted into every
526 translation unit that uses them. One example of this is tentative
527 definitions in C, such as "<tt>int X;</tt>" at global scope.
528 </dd>
529
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]531
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]532 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
533 that some targets may choose to emit different assembly sequences for them
534 for target-dependent reasons. This is used for globals that are declared
535 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]536 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]539
540 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
541 pointer to array type. When two global variables with appending linkage are
542 linked together, the two global arrays are appended together. This is the
543 LLVM, typesafe, equivalent of having the system linker append together
544 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]545 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]546
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]548 <dd>The semantics of this linkage follow the ELF object file model: the
549 symbol is weak until linked, if not linked, the symbol becomes null instead
550 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]551 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]552
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]553 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]554
555 <dd>If none of the above identifiers are used, the global is externally
556 visible, meaning that it participates in linkage and can be used to resolve
557 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]558 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]559</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]560
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]561 <p>
562 The next two types of linkage are targeted for Microsoft Windows platform
563 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]564 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]565 </p>
566
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]567 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
569
570 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
571 or variable via a global pointer to a pointer that is set up by the DLL
572 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame]573 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]574 </dd>
575
576 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
577
578 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
579 pointer to a pointer in a DLL, so that it can be referenced with the
580 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame]581 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]582 name.
583 </dd>
584
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]585</dl>
586
Dan Gohman8ef44982008-11-24 17:18:39 +0000[diff] [blame]587<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]588variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
589variable and was linked with this one, one of the two would be renamed,
590preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
591external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]592outside of the current module.</p>
593<p>It is illegal for a function <i>declaration</i>
594to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]595or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]596<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]597linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]598</div>
599
600<!-- ======================================================================= -->
601<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]602 <a name="callingconv">Calling Conventions</a>
603</div>
604
605<div class="doc_text">
606
607<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
608and <a href="#i_invoke">invokes</a> can all have an optional calling convention
609specified for the call. The calling convention of any pair of dynamic
610caller/callee must match, or the behavior of the program is undefined. The
611following calling conventions are supported by LLVM, and more may be added in
612the future:</p>
613
614<dl>
615 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
616
617 <dd>This calling convention (the default if no other calling convention is
618 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]619 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]620 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]621 </dd>
622
623 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
624
625 <dd>This calling convention attempts to make calls as fast as possible
626 (e.g. by passing things in registers). This calling convention allows the
627 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]628 without having to conform to an externally specified ABI (Application Binary
629 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]630 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
631 supported. This calling convention does not support varargs and requires the
632 prototype of all callees to exactly match the prototype of the function
633 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]634 </dd>
635
636 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
637
638 <dd>This calling convention attempts to make code in the caller as efficient
639 as possible under the assumption that the call is not commonly executed. As
640 such, these calls often preserve all registers so that the call does not break
641 any live ranges in the caller side. This calling convention does not support
642 varargs and requires the prototype of all callees to exactly match the
643 prototype of the function definition.
644 </dd>
645
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]646 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]647
648 <dd>Any calling convention may be specified by number, allowing
649 target-specific calling conventions to be used. Target specific calling
650 conventions start at 64.
651 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]652</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]653
654<p>More calling conventions can be added/defined on an as-needed basis, to
655support pascal conventions or any other well-known target-independent
656convention.</p>
657
658</div>
659
660<!-- ======================================================================= -->
661<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]662 <a name="visibility">Visibility Styles</a>
663</div>
664
665<div class="doc_text">
666
667<p>
668All Global Variables and Functions have one of the following visibility styles:
669</p>
670
671<dl>
672 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
673
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]674 <dd>On targets that use the ELF object file format, default visibility means
675 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]676 modules and, in shared libraries, means that the declared entity may be
677 overridden. On Darwin, default visibility means that the declaration is
678 visible to other modules. Default visibility corresponds to "external
679 linkage" in the language.
680 </dd>
681
682 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
683
684 <dd>Two declarations of an object with hidden visibility refer to the same
685 object if they are in the same shared object. Usually, hidden visibility
686 indicates that the symbol will not be placed into the dynamic symbol table,
687 so no other module (executable or shared library) can reference it
688 directly.
689 </dd>
690
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]691 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
692
693 <dd>On ELF, protected visibility indicates that the symbol will be placed in
694 the dynamic symbol table, but that references within the defining module will
695 bind to the local symbol. That is, the symbol cannot be overridden by another
696 module.
697 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]698</dl>
699
700</div>
701
702<!-- ======================================================================= -->
703<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]704 <a name="namedtypes">Named Types</a>
705</div>
706
707<div class="doc_text">
708
709<p>LLVM IR allows you to specify name aliases for certain types. This can make
710it easier to read the IR and make the IR more condensed (particularly when
711recursive types are involved). An example of a name specification is:
712</p>
713
714<div class="doc_code">
715<pre>
716%mytype = type { %mytype*, i32 }
717</pre>
718</div>
719
720<p>You may give a name to any <a href="#typesystem">type</a> except "<a
721href="t_void">void</a>". Type name aliases may be used anywhere a type is
722expected with the syntax "%mytype".</p>
723
724<p>Note that type names are aliases for the structural type that they indicate,
725and that you can therefore specify multiple names for the same type. This often
726leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
727structural typing, the name is not part of the type. When printing out LLVM IR,
728the printer will pick <em>one name</em> to render all types of a particular
729shape. This means that if you have code where two different source types end up
730having the same LLVM type, that the dumper will sometimes print the "wrong" or
731unexpected type. This is an important design point and isn't going to
732change.</p>
733
734</div>
735
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]736<!-- ======================================================================= -->
737<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]738 <a name="globalvars">Global Variables</a>
739</div>
740
741<div class="doc_text">
742
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]743<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]744instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]745an explicit section to be placed in, and may have an optional explicit alignment
746specified. A variable may be defined as "thread_local", which means that it
747will not be shared by threads (each thread will have a separated copy of the
748variable). A variable may be defined as a global "constant," which indicates
749that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]750optimization, allowing the global data to be placed in the read-only section of
751an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]752cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]753
754<p>
755LLVM explicitly allows <em>declarations</em> of global variables to be marked
756constant, even if the final definition of the global is not. This capability
757can be used to enable slightly better optimization of the program, but requires
758the language definition to guarantee that optimizations based on the
759'constantness' are valid for the translation units that do not include the
760definition.
761</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]762
763<p>As SSA values, global variables define pointer values that are in
764scope (i.e. they dominate) all basic blocks in the program. Global
765variables always define a pointer to their "content" type because they
766describe a region of memory, and all memory objects in LLVM are
767accessed through pointers.</p>
768
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]769<p>A global variable may be declared to reside in a target-specifc numbered
770address space. For targets that support them, address spaces may affect how
771optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]772the variable. The default address space is zero. The address space qualifier
773must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]774
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]775<p>LLVM allows an explicit section to be specified for globals. If the target
776supports it, it will emit globals to the section specified.</p>
777
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]778<p>An explicit alignment may be specified for a global. If not present, or if
779the alignment is set to zero, the alignment of the global is set by the target
780to whatever it feels convenient. If an explicit alignment is specified, the
781global is forced to have at least that much alignment. All alignments must be
782a power of 2.</p>
783
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]784<p>For example, the following defines a global in a numbered address space with
785an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]786
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]787<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]788<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]789@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]790</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]791</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]792
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]793</div>
794
795
796<!-- ======================================================================= -->
797<div class="doc_subsection">
798 <a name="functionstructure">Functions</a>
799</div>
800
801<div class="doc_text">
802
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]803<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
804an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]805<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]806<a href="#callingconv">calling convention</a>, a return type, an optional
807<a href="#paramattrs">parameter attribute</a> for the return type, a function
808name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]809<a href="#paramattrs">parameter attributes</a>), optional
810<a href="#fnattrs">function attributes</a>, an optional section,
811an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]812an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]813
814LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
815optional <a href="#linkage">linkage type</a>, an optional
816<a href="#visibility">visibility style</a>, an optional
817<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]818<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]819name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]820<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]821
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]822<p>A function definition contains a list of basic blocks, forming the CFG
823(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]824the function. Each basic block may optionally start with a label (giving the
825basic block a symbol table entry), contains a list of instructions, and ends
826with a <a href="#terminators">terminator</a> instruction (such as a branch or
827function return).</p>
828
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]829<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]830executed on entrance to the function, and it is not allowed to have predecessor
831basic blocks (i.e. there can not be any branches to the entry block of a
832function). Because the block can have no predecessors, it also cannot have any
833<a href="#i_phi">PHI nodes</a>.</p>
834
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]835<p>LLVM allows an explicit section to be specified for functions. If the target
836supports it, it will emit functions to the section specified.</p>
837
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]838<p>An explicit alignment may be specified for a function. If not present, or if
839the alignment is set to zero, the alignment of the function is set by the target
840to whatever it feels convenient. If an explicit alignment is specified, the
841function is forced to have at least that much alignment. All alignments must be
842a power of 2.</p>
843
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]844 <h5>Syntax:</h5>
845
846<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]847<tt>
848define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
849 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
850 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
851 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
852 [<a href="#gc">gc</a>] { ... }
853</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]854</div>
855
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]856</div>
857
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]858
859<!-- ======================================================================= -->
860<div class="doc_subsection">
861 <a name="aliasstructure">Aliases</a>
862</div>
863<div class="doc_text">
864 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]865 function, global variable, another alias or bitcast of global value). Aliases
866 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]867 optional <a href="#visibility">visibility style</a>.</p>
868
869 <h5>Syntax:</h5>
870
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]871<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]872<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]873@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]874</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]875</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]876
877</div>
878
879
880
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]881<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]882<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
883<div class="doc_text">
884 <p>The return type and each parameter of a function type may have a set of
885 <i>parameter attributes</i> associated with them. Parameter attributes are
886 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]887 a function. Parameter attributes are considered to be part of the function,
888 not of the function type, so functions with different parameter attributes
889 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]890
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]891 <p>Parameter attributes are simple keywords that follow the type specified. If
892 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]893 example:</p>
894
895<div class="doc_code">
896<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]897declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]898declare i32 @atoi(i8 zeroext)
899declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]900</pre>
901</div>
902
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]903 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
904 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]905
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]906 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]907 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]908 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]909 <dd>This indicates to the code generator that the parameter or return value
910 should be zero-extended to a 32-bit value by the caller (for a parameter)
911 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]912
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]913 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]914 <dd>This indicates to the code generator that the parameter or return value
915 should be sign-extended to a 32-bit value by the caller (for a parameter)
916 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]917
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]918 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]919 <dd>This indicates that this parameter or return value should be treated
920 in a special target-dependent fashion during while emitting code for a
921 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]922 to memory, though some targets use it to distinguish between two different
923 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]924
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]925 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]926 <dd>This indicates that the pointer parameter should really be passed by
927 value to the function. The attribute implies that a hidden copy of the
928 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]929 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]930 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]931 value, but is also valid on pointers to scalars. The copy is considered to
932 belong to the caller not the callee (for example,
933 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]934 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner08aa9062009-02-05 05:42:28 +0000[diff] [blame]935 values. The byval attribute also supports specifying an alignment with the
936 align attribute. This has a target-specific effect on the code generator
937 that usually indicates a desired alignment for the synthesized stack
938 slot.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]939
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]940 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]941 <dd>This indicates that the pointer parameter specifies the address of a
942 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]943 This pointer must be guaranteed by the caller to be valid: loads and stores
944 to the structure may be assumed by the callee to not to trap. This may only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]945 be applied to the first parameter. This is not a valid attribute for
946 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]947
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]948 <dt><tt>noalias</tt></dt>
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]949 <dd>This indicates that the pointer does not alias any global or any other
950 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyd59572c2008-11-24 05:00:44 +0000[diff] [blame]951 case. On a function return value, <tt>noalias</tt> additionally indicates
952 that the pointer does not alias any other pointers visible to the
Nick Lewycky2abb1082008-12-19 06:39:12 +0000[diff] [blame]953 caller. For further details, please see the discussion of the NoAlias
954 response in
955 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
956 analysis</a>.</dd>
957
958 <dt><tt>nocapture</tt></dt>
959 <dd>This indicates that the callee does not make any copies of the pointer
960 that outlive the callee itself. This is not a valid attribute for return
961 values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]962
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]963 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]964 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]965 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
966 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]967 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]968
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]969</div>
970
971<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]972<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]973 <a name="gc">Garbage Collector Names</a>
974</div>
975
976<div class="doc_text">
977<p>Each function may specify a garbage collector name, which is simply a
978string.</p>
979
980<div class="doc_code"><pre
981>define void @f() gc "name" { ...</pre></div>
982
983<p>The compiler declares the supported values of <i>name</i>. Specifying a
984collector which will cause the compiler to alter its output in order to support
985the named garbage collection algorithm.</p>
986</div>
987
988<!-- ======================================================================= -->
989<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]990 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]991</div>
992
993<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]994
995<p>Function attributes are set to communicate additional information about
996 a function. Function attributes are considered to be part of the function,
997 not of the function type, so functions with different parameter attributes
998 can have the same function type.</p>
999
1000 <p>Function attributes are simple keywords that follow the type specified. If
1001 multiple attributes are needed, they are space separated. For
1002 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1003
1004<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1005<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1006define void @f() noinline { ... }
1007define void @f() alwaysinline { ... }
1008define void @f() alwaysinline optsize { ... }
1009define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1010</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1011</div>
1012
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1013<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1014<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1015<dd>This attribute indicates that the inliner should attempt to inline this
1016function into callers whenever possible, ignoring any active inlining size
1017threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1018
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1019<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1020<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]1021in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1022<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1023
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1024<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]1025<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1026make choices that keep the code size of this function low, and otherwise do
1027optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1028
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1029<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1030<dd>This function attribute indicates that the function never returns normally.
1031This produces undefined behavior at runtime if the function ever does
1032dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1033
1034<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1035<dd>This function attribute indicates that the function never returns with an
1036unwind or exceptional control flow. If the function does unwind, its runtime
1037behavior is undefined.</dd>
1038
1039<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1040<dd>This attribute indicates that the function computes its result (or the
1041exception it throws) based strictly on its arguments, without dereferencing any
1042pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1043registers, etc) visible to caller functions. It does not write through any
1044pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1045never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1046
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1047<dt><tt><a name="readonly">readonly</a></tt></dt>
1048<dd>This attribute indicates that the function does not write through any
1049pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1050or otherwise modify any state (e.g. memory, control registers, etc) visible to
1051caller functions. It may dereference pointer arguments and read state that may
1052be set in the caller. A readonly function always returns the same value (or
1053throws the same exception) when called with the same set of arguments and global
1054state.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1055
1056<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1057<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1058protector. It is in the form of a "canary"&mdash;a random value placed on the
1059stack before the local variables that's checked upon return from the function to
1060see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1061needs stack protectors or not.
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1062
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1063<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1064that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1065have an <tt>ssp</tt> attribute.</p></dd>
1066
1067<dt><tt>sspreq</tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1068<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1069stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1070function attribute.
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1071
1072<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1073function that doesn't have an <tt>sspreq</tt> attribute or which has
1074an <tt>ssp</tt> attribute, then the resulting function will have
1075an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1076</dl>
1077
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1078</div>
1079
1080<!-- ======================================================================= -->
1081<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1082 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1083</div>
1084
1085<div class="doc_text">
1086<p>
1087Modules may contain "module-level inline asm" blocks, which corresponds to the
1088GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1089LLVM and treated as a single unit, but may be separated in the .ll file if
1090desired. The syntax is very simple:
1091</p>
1092
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1093<div class="doc_code">
1094<pre>
1095module asm "inline asm code goes here"
1096module asm "more can go here"
1097</pre>
1098</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1099
1100<p>The strings can contain any character by escaping non-printable characters.
1101 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1102 for the number.
1103</p>
1104
1105<p>
1106 The inline asm code is simply printed to the machine code .s file when
1107 assembly code is generated.
1108</p>
1109</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1110
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1111<!-- ======================================================================= -->
1112<div class="doc_subsection">
1113 <a name="datalayout">Data Layout</a>
1114</div>
1115
1116<div class="doc_text">
1117<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1118data is to be laid out in memory. The syntax for the data layout is simply:</p>
1119<pre> target datalayout = "<i>layout specification</i>"</pre>
1120<p>The <i>layout specification</i> consists of a list of specifications
1121separated by the minus sign character ('-'). Each specification starts with a
1122letter and may include other information after the letter to define some
1123aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1124<dl>
1125 <dt><tt>E</tt></dt>
1126 <dd>Specifies that the target lays out data in big-endian form. That is, the
1127 bits with the most significance have the lowest address location.</dd>
1128 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1129 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1130 the bits with the least significance have the lowest address location.</dd>
1131 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1132 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1133 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1134 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1135 too.</dd>
1136 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1137 <dd>This specifies the alignment for an integer type of a given bit
1138 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1139 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1140 <dd>This specifies the alignment for a vector type of a given bit
1141 <i>size</i>.</dd>
1142 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1143 <dd>This specifies the alignment for a floating point type of a given bit
1144 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1145 (double).</dd>
1146 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1147 <dd>This specifies the alignment for an aggregate type of a given bit
1148 <i>size</i>.</dd>
1149</dl>
1150<p>When constructing the data layout for a given target, LLVM starts with a
1151default set of specifications which are then (possibly) overriden by the
1152specifications in the <tt>datalayout</tt> keyword. The default specifications
1153are given in this list:</p>
1154<ul>
1155 <li><tt>E</tt> - big endian</li>
1156 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1157 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1158 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1159 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1160 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1161 <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]1162 alignment of 64-bits</li>
1163 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1164 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1165 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1166 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1167 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1168</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1169<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1170following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1171<ol>
1172 <li>If the type sought is an exact match for one of the specifications, that
1173 specification is used.</li>
1174 <li>If no match is found, and the type sought is an integer type, then the
1175 smallest integer type that is larger than the bitwidth of the sought type is
1176 used. If none of the specifications are larger than the bitwidth then the the
1177 largest integer type is used. For example, given the default specifications
1178 above, the i7 type will use the alignment of i8 (next largest) while both
1179 i65 and i256 will use the alignment of i64 (largest specified).</li>
1180 <li>If no match is found, and the type sought is a vector type, then the
1181 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1182 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1183 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1184</ol>
1185</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1186
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1187<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1188<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1189<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1190
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1191<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1192
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1193<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1194intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1195optimizations to be performed on the intermediate representation directly,
1196without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1197extra analyses on the side before the transformation. A strong type
1198system makes it easier to read the generated code and enables novel
1199analyses and transformations that are not feasible to perform on normal
1200three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1201
1202</div>
1203
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1204<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1205<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1206Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1207<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1208<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1209classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1210
1211<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1212 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1213 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1214 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1215 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1216 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1217 </tr>
1218 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1219 <td><a href="#t_floating">floating point</a></td>
1220 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1221 </tr>
1222 <tr>
1223 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1224 <td><a href="#t_integer">integer</a>,
1225 <a href="#t_floating">floating point</a>,
1226 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1227 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1228 <a href="#t_struct">structure</a>,
1229 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1230 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1231 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1232 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1233 <tr>
1234 <td><a href="#t_primitive">primitive</a></td>
1235 <td><a href="#t_label">label</a>,
1236 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1237 <a href="#t_floating">floating point</a>.</td>
1238 </tr>
1239 <tr>
1240 <td><a href="#t_derived">derived</a></td>
1241 <td><a href="#t_integer">integer</a>,
1242 <a href="#t_array">array</a>,
1243 <a href="#t_function">function</a>,
1244 <a href="#t_pointer">pointer</a>,
1245 <a href="#t_struct">structure</a>,
1246 <a href="#t_pstruct">packed structure</a>,
1247 <a href="#t_vector">vector</a>,
1248 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1249 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1250 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1251 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1252</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1253
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1254<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1255most important. Values of these types are the only ones which can be
1256produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1257instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1258</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1259
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1260<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1261<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1262
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1263<div class="doc_text">
1264<p>The primitive types are the fundamental building blocks of the LLVM
1265system.</p>
1266
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1267</div>
1268
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1269<!-- _______________________________________________________________________ -->
1270<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1271
1272<div class="doc_text">
1273 <table>
1274 <tbody>
1275 <tr><th>Type</th><th>Description</th></tr>
1276 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1277 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1278 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1279 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1280 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1281 </tbody>
1282 </table>
1283</div>
1284
1285<!-- _______________________________________________________________________ -->
1286<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1287
1288<div class="doc_text">
1289<h5>Overview:</h5>
1290<p>The void type does not represent any value and has no size.</p>
1291
1292<h5>Syntax:</h5>
1293
1294<pre>
1295 void
1296</pre>
1297</div>
1298
1299<!-- _______________________________________________________________________ -->
1300<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1301
1302<div class="doc_text">
1303<h5>Overview:</h5>
1304<p>The label type represents code labels.</p>
1305
1306<h5>Syntax:</h5>
1307
1308<pre>
1309 label
1310</pre>
1311</div>
1312
1313
1314<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1315<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1316
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1317<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1318
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1319<p>The real power in LLVM comes from the derived types in the system.
1320This is what allows a programmer to represent arrays, functions,
1321pointers, and other useful types. Note that these derived types may be
1322recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1323
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1324</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1326<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1327<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1328
1329<div class="doc_text">
1330
1331<h5>Overview:</h5>
1332<p>The integer type is a very simple derived type that simply specifies an
1333arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13342^23-1 (about 8 million) can be specified.</p>
1335
1336<h5>Syntax:</h5>
1337
1338<pre>
1339 iN
1340</pre>
1341
1342<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1343value.</p>
1344
1345<h5>Examples:</h5>
1346<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1347 <tbody>
1348 <tr>
1349 <td><tt>i1</tt></td>
1350 <td>a single-bit integer.</td>
1351 </tr><tr>
1352 <td><tt>i32</tt></td>
1353 <td>a 32-bit integer.</td>
1354 </tr><tr>
1355 <td><tt>i1942652</tt></td>
1356 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1357 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1358 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1359</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1360
1361<p>Note that the code generator does not yet support large integer types
1362to be used as function return types. The specific limit on how large a
1363return type the code generator can currently handle is target-dependent;
1364currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1365targets.</p>
1366
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1367</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1368
1369<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1370<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1371
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1372<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1373
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1374<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1375
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1376<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1377sequentially in memory. The array type requires a size (number of
1378elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1379
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1380<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1381
1382<pre>
1383 [&lt;# elements&gt; x &lt;elementtype&gt;]
1384</pre>
1385
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1386<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1387be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1388
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1389<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1390<table class="layout">
1391 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1392 <td class="left"><tt>[40 x i32]</tt></td>
1393 <td class="left">Array of 40 32-bit integer values.</td>
1394 </tr>
1395 <tr class="layout">
1396 <td class="left"><tt>[41 x i32]</tt></td>
1397 <td class="left">Array of 41 32-bit integer values.</td>
1398 </tr>
1399 <tr class="layout">
1400 <td class="left"><tt>[4 x i8]</tt></td>
1401 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1402 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1403</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1404<p>Here are some examples of multidimensional arrays:</p>
1405<table class="layout">
1406 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1407 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1408 <td class="left">3x4 array of 32-bit integer values.</td>
1409 </tr>
1410 <tr class="layout">
1411 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1412 <td class="left">12x10 array of single precision floating point values.</td>
1413 </tr>
1414 <tr class="layout">
1415 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1416 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1417 </tr>
1418</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1419
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1420<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1421length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1422LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1423As a special case, however, zero length arrays are recognized to be variable
1424length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1425type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1426
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1427<p>Note that the code generator does not yet support large aggregate types
1428to be used as function return types. The specific limit on how large an
1429aggregate return type the code generator can currently handle is
1430target-dependent, and also dependent on the aggregate element types.</p>
1431
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1432</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1433
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1434<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1435<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1436<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1437
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1438<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1439
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1440<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1441consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1442return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel9c1f8b12008-03-24 20:52:42 +0000[diff] [blame]1443If the return type is a struct type then all struct elements must be of first
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1444class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1445
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1446<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1447
1448<pre>
1449 &lt;returntype list&gt; (&lt;parameter list&gt;)
1450</pre>
1451
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1452<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukman20f9a622004-08-12 20:16:08 +0000[diff] [blame]1453specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1454which indicates that the function takes a variable number of arguments.
1455Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1456 href="#int_varargs">variable argument handling intrinsic</a> functions.
1457'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1458<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1459
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1460<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1461<table class="layout">
1462 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1463 <td class="left"><tt>i32 (i32)</tt></td>
1464 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1465 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1466 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1467 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1468 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1469 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1470 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1471 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1472 <tt>float</tt>.
1473 </td>
1474 </tr><tr class="layout">
1475 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1476 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1477 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1478 which returns an integer. This is the signature for <tt>printf</tt> in
1479 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1480 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1481 </tr><tr class="layout">
1482 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1483 <td class="left">A function taking an <tt>i32</tt>, returning two
1484 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1485 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1486 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1487</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1488
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1489</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1490<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1491<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1492<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1493<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1494<p>The structure type is used to represent a collection of data members
1495together in memory. The packing of the field types is defined to match
1496the ABI of the underlying processor. The elements of a structure may
1497be any type that has a size.</p>
1498<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1499and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1500field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1501instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1502<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1503<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1504<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1505<table class="layout">
1506 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1507 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1508 <td class="left">A triple of three <tt>i32</tt> values</td>
1509 </tr><tr class="layout">
1510 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1511 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1512 second element is a <a href="#t_pointer">pointer</a> to a
1513 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1514 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1515 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1516</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1517
1518<p>Note that the code generator does not yet support large aggregate types
1519to be used as function return types. The specific limit on how large an
1520aggregate return type the code generator can currently handle is
1521target-dependent, and also dependent on the aggregate element types.</p>
1522
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1523</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1524
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1525<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1526<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1527</div>
1528<div class="doc_text">
1529<h5>Overview:</h5>
1530<p>The packed structure type is used to represent a collection of data members
1531together in memory. There is no padding between fields. Further, the alignment
1532of a packed structure is 1 byte. The elements of a packed structure may
1533be any type that has a size.</p>
1534<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1535and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1536field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1537instruction.</p>
1538<h5>Syntax:</h5>
1539<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1540<h5>Examples:</h5>
1541<table class="layout">
1542 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1543 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1544 <td class="left">A triple of three <tt>i32</tt> values</td>
1545 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1546 <td class="left">
1547<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1548 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1549 second element is a <a href="#t_pointer">pointer</a> to a
1550 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1551 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1552 </tr>
1553</table>
1554</div>
1555
1556<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1557<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1558<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1559<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1560<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1561reference to another object, which must live in memory. Pointer types may have
1562an optional address space attribute defining the target-specific numbered
1563address space where the pointed-to object resides. The default address space is
1564zero.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1565
1566<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattnerd1d4cff2009-02-08 22:21:28 +0000[diff] [blame]1567it permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1568
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1569<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1570<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1571<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1572<table class="layout">
1573 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1574 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1575 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1576 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1577 </tr>
1578 <tr class="layout">
1579 <td class="left"><tt>i32 (i32 *) *</tt></td>
1580 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1581 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1582 <tt>i32</tt>.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1586 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1587 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1588 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1589</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1590</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1591
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1592<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1593<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1594<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1595
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1596<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1597
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1598<p>A vector type is a simple derived type that represents a vector
1599of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1600are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1601A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1602elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1603of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1604considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1605
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1606<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1607
1608<pre>
1609 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1610</pre>
1611
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1612<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1613be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1614
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1615<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1616
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1617<table class="layout">
1618 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1619 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1620 <td class="left">Vector of 4 32-bit integer values.</td>
1621 </tr>
1622 <tr class="layout">
1623 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1624 <td class="left">Vector of 8 32-bit floating-point values.</td>
1625 </tr>
1626 <tr class="layout">
1627 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1628 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1629 </tr>
1630</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1631
1632<p>Note that the code generator does not yet support large vector types
1633to be used as function return types. The specific limit on how large a
1634vector return type codegen can currently handle is target-dependent;
1635currently it's often a few times longer than a hardware vector register.</p>
1636
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1637</div>
1638
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1639<!-- _______________________________________________________________________ -->
1640<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1641<div class="doc_text">
1642
1643<h5>Overview:</h5>
1644
1645<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1646corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1647In LLVM, opaque types can eventually be resolved to any type (not just a
1648structure type).</p>
1649
1650<h5>Syntax:</h5>
1651
1652<pre>
1653 opaque
1654</pre>
1655
1656<h5>Examples:</h5>
1657
1658<table class="layout">
1659 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1660 <td class="left"><tt>opaque</tt></td>
1661 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1662 </tr>
1663</table>
1664</div>
1665
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1666<!-- ======================================================================= -->
1667<div class="doc_subsection">
1668 <a name="t_uprefs">Type Up-references</a>
1669</div>
1670
1671<div class="doc_text">
1672<h5>Overview:</h5>
1673<p>
1674An "up reference" allows you to refer to a lexically enclosing type without
1675requiring it to have a name. For instance, a structure declaration may contain a
1676pointer to any of the types it is lexically a member of. Example of up
1677references (with their equivalent as named type declarations) include:</p>
1678
1679<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1680 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1681 { \2 }* %y = type { %y }*
1682 \1* %z = type %z*
1683</pre>
1684
1685<p>
1686An up reference is needed by the asmprinter for printing out cyclic types when
1687there is no declared name for a type in the cycle. Because the asmprinter does
1688not want to print out an infinite type string, it needs a syntax to handle
1689recursive types that have no names (all names are optional in llvm IR).
1690</p>
1691
1692<h5>Syntax:</h5>
1693<pre>
1694 \&lt;level&gt;
1695</pre>
1696
1697<p>
1698The level is the count of the lexical type that is being referred to.
1699</p>
1700
1701<h5>Examples:</h5>
1702
1703<table class="layout">
1704 <tr class="layout">
1705 <td class="left"><tt>\1*</tt></td>
1706 <td class="left">Self-referential pointer.</td>
1707 </tr>
1708 <tr class="layout">
1709 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1710 <td class="left">Recursive structure where the upref refers to the out-most
1711 structure.</td>
1712 </tr>
1713</table>
1714</div>
1715
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1716
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1717<!-- *********************************************************************** -->
1718<div class="doc_section"> <a name="constants">Constants</a> </div>
1719<!-- *********************************************************************** -->
1720
1721<div class="doc_text">
1722
1723<p>LLVM has several different basic types of constants. This section describes
1724them all and their syntax.</p>
1725
1726</div>
1727
1728<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1729<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1730
1731<div class="doc_text">
1732
1733<dl>
1734 <dt><b>Boolean constants</b></dt>
1735
1736 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1737 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1738 </dd>
1739
1740 <dt><b>Integer constants</b></dt>
1741
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1742 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1743 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1744 integer types.
1745 </dd>
1746
1747 <dt><b>Floating point constants</b></dt>
1748
1749 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1750 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1751 notation (see below). The assembler requires the exact decimal value of
1752 a floating-point constant. For example, the assembler accepts 1.25 but
1753 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1754 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1755
1756 <dt><b>Null pointer constants</b></dt>
1757
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1758 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1759 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1760
1761</dl>
1762
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1763<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1764of floating point constants. For example, the form '<tt>double
17650x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17664.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1767(and the only time that they are generated by the disassembler) is when a
1768floating point constant must be emitted but it cannot be represented as a
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1769decimal floating point number in a reasonable number of digits. For example,
1770NaN's, infinities, and other
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1771special values are represented in their IEEE hexadecimal format so that
1772assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1773<p>When using the hexadecimal form, constants of types float and double are
1774represented using the 16-digit form shown above (which matches the IEEE754
1775representation for double); float values must, however, be exactly representable
1776as IEE754 single precision.
1777Hexadecimal format is always used for long
1778double, and there are three forms of long double. The 80-bit
1779format used by x86 is represented as <tt>0xK</tt>
1780followed by 20 hexadecimal digits.
1781The 128-bit format used by PowerPC (two adjacent doubles) is represented
1782by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
1783format is represented
1784by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
1785target uses this format. Long doubles will only work if they match
1786the long double format on your target. All hexadecimal formats are big-endian
1787(sign bit at the left).</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1788</div>
1789
1790<!-- ======================================================================= -->
1791<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1792</div>
1793
1794<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1795<p>Aggregate constants arise from aggregation of simple constants
1796and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1797
1798<dl>
1799 <dt><b>Structure constants</b></dt>
1800
1801 <dd>Structure constants are represented with notation similar to structure
1802 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1803 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1804 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1805 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1806 types of elements must match those specified by the type.
1807 </dd>
1808
1809 <dt><b>Array constants</b></dt>
1810
1811 <dd>Array constants are represented with notation similar to array type
1812 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1813 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1814 constants must have <a href="#t_array">array type</a>, and the number and
1815 types of elements must match those specified by the type.
1816 </dd>
1817
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1818 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1819
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1820 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1821 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1822 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1823 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1824 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1825 match those specified by the type.
1826 </dd>
1827
1828 <dt><b>Zero initialization</b></dt>
1829
1830 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1831 value to zero of <em>any</em> type, including scalar and aggregate types.
1832 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1833 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1834 initializers.
1835 </dd>
1836</dl>
1837
1838</div>
1839
1840<!-- ======================================================================= -->
1841<div class="doc_subsection">
1842 <a name="globalconstants">Global Variable and Function Addresses</a>
1843</div>
1844
1845<div class="doc_text">
1846
1847<p>The addresses of <a href="#globalvars">global variables</a> and <a
1848href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1849constants. These constants are explicitly referenced when the <a
1850href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1851href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1852file:</p>
1853
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1854<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1855<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1856@X = global i32 17
1857@Y = global i32 42
1858@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1859</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1860</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1861
1862</div>
1863
1864<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1865<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1866<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1867 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1868 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1869 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1870
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1871 <p>Undefined values indicate to the compiler that the program is well defined
1872 no matter what value is used, giving the compiler more freedom to optimize.
1873 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1874</div>
1875
1876<!-- ======================================================================= -->
1877<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1878</div>
1879
1880<div class="doc_text">
1881
1882<p>Constant expressions are used to allow expressions involving other constants
1883to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1884href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1885that does not have side effects (e.g. load and call are not supported). The
1886following is the syntax for constant expressions:</p>
1887
1888<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1889 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1890 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1891 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1892
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1893 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1894 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1895 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1896
1897 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1898 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1899 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1900
1901 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1902 <dd>Truncate a floating point constant to another floating point type. The
1903 size of CST must be larger than the size of TYPE. Both types must be
1904 floating point.</dd>
1905
1906 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1907 <dd>Floating point extend a constant to another type. The size of CST must be
1908 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1909
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1910 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1911 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1912 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1913 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1914 of the same number of elements. If the value won't fit in the integer type,
1915 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1916
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1917 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1918 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1919 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1920 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1921 of the same number of elements. If the value won't fit in the integer type,
1922 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1923
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1924 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1925 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1926 constant. TYPE must be a scalar or vector floating point type. CST must be of
1927 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1928 of the same number of elements. If the value won't fit in the floating point
1929 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1930
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1931 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1932 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1933 constant. TYPE must be a scalar or vector floating point type. CST must be of
1934 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1935 of the same number of elements. If the value won't fit in the floating point
1936 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1937
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1938 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1939 <dd>Convert a pointer typed constant to the corresponding integer constant
1940 TYPE must be an integer type. CST must be of pointer type. The CST value is
1941 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1942
1943 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1944 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1945 pointer type. CST must be of integer type. The CST value is zero extended,
1946 truncated, or unchanged to make it fit in a pointer size. This one is
1947 <i>really</i> dangerous!</dd>
1948
1949 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1950 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1951 identical (same number of bits). The conversion is done as if the CST value
1952 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1953 with this operator, just the type. This can be used for conversion of
Nick Lewyckycd5b1442009-02-28 17:30:06 +0000[diff] [blame]1954 aggregate types to any aggregate type, as long as they have the same bit
1955 width. Vector types may also be casted to and from any other type as long as
1956 they have the same bit width. For pointers it is only valid to cast to
1957 another pointer type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1958 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1959
1960 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1961
1962 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1963 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1964 instruction, the index list may have zero or more indexes, which are required
1965 to make sense for the type of "CSTPTR".</dd>
1966
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1967 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1968
1969 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1970 constants.</dd>
1971
1972 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1973 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1974
1975 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1976 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1977
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1978 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1979 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1980
1981 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1982 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1983
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1984 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1985
1986 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1987 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1988
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1989 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1990
1991 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1992 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1993
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1994
1995 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1996
1997 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1998 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1999
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2000 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
2001
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2002 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2003 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2004 binary</a> operations. The constraints on operands are the same as those for
2005 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2006 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2007</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2008</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2009
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2010<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2011<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2012<!-- *********************************************************************** -->
2013
2014<!-- ======================================================================= -->
2015<div class="doc_subsection">
2016<a name="inlineasm">Inline Assembler Expressions</a>
2017</div>
2018
2019<div class="doc_text">
2020
2021<p>
2022LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
2023Module-Level Inline Assembly</a>) through the use of a special value. This
2024value represents the inline assembler as a string (containing the instructions
2025to emit), a list of operand constraints (stored as a string), and a flag that
2026indicates whether or not the inline asm expression has side effects. An example
2027inline assembler expression is:
2028</p>
2029
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2030<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2031<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2032i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2033</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2034</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2035
2036<p>
2037Inline assembler expressions may <b>only</b> be used as the callee operand of
2038a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2039</p>
2040
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2041<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2042<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2043%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]2044</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2045</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2046
2047<p>
2048Inline asms with side effects not visible in the constraint list must be marked
2049as having side effects. This is done through the use of the
2050'<tt>sideeffect</tt>' keyword, like so:
2051</p>
2052
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2053<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2054<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2055call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2056</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2057</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2058
2059<p>TODO: The format of the asm and constraints string still need to be
2060documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]2061need to be documented). This is probably best done by reference to another
2062document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2063</p>
2064
2065</div>
2066
2067<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2068<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2069<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2070
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2071<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2072
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2073<p>The LLVM instruction set consists of several different
2074classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2075instructions</a>, <a href="#binaryops">binary instructions</a>,
2076<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2077 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2078instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2079
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2080</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2082<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2083<div class="doc_subsection"> <a name="terminators">Terminator
2084Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2085
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2086<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2087
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2088<p>As mentioned <a href="#functionstructure">previously</a>, every
2089basic block in a program ends with a "Terminator" instruction, which
2090indicates which block should be executed after the current block is
2091finished. These terminator instructions typically yield a '<tt>void</tt>'
2092value: they produce control flow, not values (the one exception being
2093the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2094<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2095 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2096instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2097the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2098 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2099 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2100
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2101</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2103<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2104<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2105Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2106<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2107<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2108<pre>
2109 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]2110 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2111</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2112
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2113<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2114
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2115<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2116optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]2117<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2118returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2119control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2120
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2121<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2122
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2123<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2124the return value. The type of the return value must be a
2125'<a href="#t_firstclass">first class</a>' type.</p>
2126
2127<p>A function is not <a href="#wellformed">well formed</a> if
2128it it has a non-void return type and contains a '<tt>ret</tt>'
2129instruction with no return value or a return value with a type that
2130does not match its type, or if it has a void return type and contains
2131a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2132
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2133<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2134
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2135<p>When the '<tt>ret</tt>' instruction is executed, control flow
2136returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]2137 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2138the instruction after the call. If the caller was an "<a
2139 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2140at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2141returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2142return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2143
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2144<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2145
2146<pre>
2147 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2148 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2149 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2150</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2151
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2152<p>Note that the code generator does not yet fully support large
2153 return values. The specific sizes that are currently supported are
2154 dependent on the target. For integers, on 32-bit targets the limit
2155 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2156 For aggregate types, the current limits are dependent on the element
2157 types; for example targets are often limited to 2 total integer
2158 elements and 2 total floating-point elements.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2159
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2160</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2161<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2162<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2163<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2164<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2165<pre> 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]2166</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2167<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2168<p>The '<tt>br</tt>' instruction is used to cause control flow to
2169transfer to a different basic block in the current function. There are
2170two forms of this instruction, corresponding to a conditional branch
2171and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2172<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2173<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2174single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]2175unconditional form of the '<tt>br</tt>' instruction takes a single
2176'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2177<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2178<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2179argument is evaluated. If the value is <tt>true</tt>, control flows
2180to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2181control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2182<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2183<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2184 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2185</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2186<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2187<div class="doc_subsubsection">
2188 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2189</div>
2190
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2191<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2192<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2193
2194<pre>
2195 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2196</pre>
2197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2198<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2199
2200<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2201several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2202instruction, allowing a branch to occur to one of many possible
2203destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2204
2205
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2206<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2207
2208<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2209comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2210an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2211table is not allowed to contain duplicate constant entries.</p>
2212
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2213<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2214
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2215<p>The <tt>switch</tt> instruction specifies a table of values and
2216destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2217table is searched for the given value. If the value is found, control flow is
2218transfered to the corresponding destination; otherwise, control flow is
2219transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2220
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2221<h5>Implementation:</h5>
2222
2223<p>Depending on properties of the target machine and the particular
2224<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2225ways. For example, it could be generated as a series of chained conditional
2226branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2227
2228<h5>Example:</h5>
2229
2230<pre>
2231 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2232 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2233 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2234
2235 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2236 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2237
2238 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2239 switch i32 %val, label %otherwise [ i32 0, label %onzero
2240 i32 1, label %onone
2241 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2242</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2243</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2244
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2245<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2246<div class="doc_subsubsection">
2247 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2248</div>
2249
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2250<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2251
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2252<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2253
2254<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2255 &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]2256 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2257</pre>
2258
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2259<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2260
2261<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2262function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2263'<tt>normal</tt>' label or the
2264'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2265"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2266"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2267href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2268continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2269
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2270<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2271
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2272<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2273
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2274<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2275 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2276 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2277 convention</a> the call should use. If none is specified, the call defaults
2278 to using C calling conventions.
2279 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2280
2281 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2282 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2283 and '<tt>inreg</tt>' attributes are valid here.</li>
2284
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2285 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2286 function value being invoked. In most cases, this is a direct function
2287 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2288 an arbitrary pointer to function value.
2289 </li>
2290
2291 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2292 function to be invoked. </li>
2293
2294 <li>'<tt>function args</tt>': argument list whose types match the function
2295 signature argument types. If the function signature indicates the function
2296 accepts a variable number of arguments, the extra arguments can be
2297 specified. </li>
2298
2299 <li>'<tt>normal label</tt>': the label reached when the called function
2300 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2301
2302 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2303 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2304
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2305 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2306 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2307 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2308</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2311
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2312<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2313href="#i_call">call</a></tt>' instruction in most regards. The primary
2314difference is that it establishes an association with a label, which is used by
2315the runtime library to unwind the stack.</p>
2316
2317<p>This instruction is used in languages with destructors to ensure that proper
2318cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2319exception. Additionally, this is important for implementation of
2320'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2322<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2323<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2324 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2325 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2326 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2327 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2328</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2329</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2330
2331
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2332<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2333
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2334<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2335Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2336
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2337<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2338
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2339<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2340<pre>
2341 unwind
2342</pre>
2343
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2344<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2345
2346<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2347at the first callee in the dynamic call stack which used an <a
2348href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2349primarily used to implement exception handling.</p>
2350
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2351<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2352
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2353<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2354immediately halt. The dynamic call stack is then searched for the first <a
2355href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2356execution continues at the "exceptional" destination block specified by the
2357<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2358dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2359</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2360
2361<!-- _______________________________________________________________________ -->
2362
2363<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2364Instruction</a> </div>
2365
2366<div class="doc_text">
2367
2368<h5>Syntax:</h5>
2369<pre>
2370 unreachable
2371</pre>
2372
2373<h5>Overview:</h5>
2374
2375<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2376instruction is used to inform the optimizer that a particular portion of the
2377code is not reachable. This can be used to indicate that the code after a
2378no-return function cannot be reached, and other facts.</p>
2379
2380<h5>Semantics:</h5>
2381
2382<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2383</div>
2384
2385
2386
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2387<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2388<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2389<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2390<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2391program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2392produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2393multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2394The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2395<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2396</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2397<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2398<div class="doc_subsubsection">
2399 <a name="i_add">'<tt>add</tt>' Instruction</a>
2400</div>
2401
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2402<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2403
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2404<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2405
2406<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2407 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2408</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2409
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2410<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2411
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2412<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2413
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2414<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2415
2416<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2417 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2418 <a href="#t_vector">vector</a> values. Both arguments must have identical
2419 types.</p>
2420
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2421<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2422
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2423<p>The value produced is the integer or floating point sum of the two
2424operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2425
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2426<p>If an integer sum has unsigned overflow, the result returned is the
2427mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2428the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2429
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2430<p>Because LLVM integers use a two's complement representation, this
2431instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2432
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2433<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2434
2435<pre>
2436 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2437</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2438</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2439<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2440<div class="doc_subsubsection">
2441 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2442</div>
2443
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2444<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2445
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2446<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2447
2448<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2449 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2450</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2451
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2452<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2453
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2454<p>The '<tt>sub</tt>' instruction returns the difference of its two
2455operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2456
2457<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2458'<tt>neg</tt>' instruction present in most other intermediate
2459representations.</p>
2460
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2461<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2462
2463<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2464 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2465 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2466 types.</p>
2467
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2468<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2469
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2470<p>The value produced is the integer or floating point difference of
2471the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2472
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2473<p>If an integer difference has unsigned overflow, the result returned is the
2474mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2475the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2476
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2477<p>Because LLVM integers use a two's complement representation, this
2478instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2479
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2480<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2481<pre>
2482 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2483 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2484</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2485</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2486
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2487<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2488<div class="doc_subsubsection">
2489 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2490</div>
2491
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2492<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2493
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2494<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2495<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2496</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2497<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2498<p>The '<tt>mul</tt>' instruction returns the product of its two
2499operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2500
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2501<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2502
2503<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2504href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2505or <a href="#t_vector">vector</a> values. Both arguments must have identical
2506types.</p>
2507
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2508<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2509
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2510<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2511two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2512
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2513<p>If the result of an integer multiplication has unsigned overflow,
2514the result returned is the mathematical result modulo
25152<sup>n</sup>, where n is the bit width of the result.</p>
2516<p>Because LLVM integers use a two's complement representation, and the
2517result is the same width as the operands, this instruction returns the
2518correct result for both signed and unsigned integers. If a full product
2519(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2520should be sign-extended or zero-extended as appropriate to the
2521width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2522<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2523<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2524</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2525</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2526
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2527<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2528<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2529</a></div>
2530<div class="doc_text">
2531<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2532<pre> &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]2533</pre>
2534<h5>Overview:</h5>
2535<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2536operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2537
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2538<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2539
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2540<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2541<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2542values. Both arguments must have identical types.</p>
2543
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2544<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2545
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2546<p>The value produced is the unsigned integer quotient of the two operands.</p>
2547<p>Note that unsigned integer division and signed integer division are distinct
2548operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2549<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2550<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2551<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2552</pre>
2553</div>
2554<!-- _______________________________________________________________________ -->
2555<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2556</a> </div>
2557<div class="doc_text">
2558<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2559<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2560 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2561</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2562
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2563<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2564
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2565<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2566operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2567
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2568<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2569
2570<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2571<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2572values. Both arguments must have identical types.</p>
2573
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2574<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2575<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2576<p>Note that signed integer division and unsigned integer division are distinct
2577operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2578<p>Division by zero leads to undefined behavior. Overflow also leads to
2579undefined behavior; this is a rare case, but can occur, for example,
2580by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2581<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2582<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2583</pre>
2584</div>
2585<!-- _______________________________________________________________________ -->
2586<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2587Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2588<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2589<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2590<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2591 &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]2592</pre>
2593<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2594
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2595<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2596operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2597
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2598<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2599
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2600<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2601<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2602of floating point values. Both arguments must have identical types.</p>
2603
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2604<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2605
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2606<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2607
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2608<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2609
2610<pre>
2611 &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]2612</pre>
2613</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2614
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2615<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2616<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2617</div>
2618<div class="doc_text">
2619<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2620<pre> &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]2621</pre>
2622<h5>Overview:</h5>
2623<p>The '<tt>urem</tt>' instruction returns the remainder from the
2624unsigned division of its two arguments.</p>
2625<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2626<p>The two arguments to the '<tt>urem</tt>' instruction must be
2627<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2628values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2629<h5>Semantics:</h5>
2630<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2631This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2632<p>Note that unsigned integer remainder and signed integer remainder are
2633distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2634<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2635<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2636<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2637</pre>
2638
2639</div>
2640<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2641<div class="doc_subsubsection">
2642 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2643</div>
2644
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2645<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2646
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2647<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2648
2649<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2650 &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]2651</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2652
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2653<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2654
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2655<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2656signed division of its two operands. This instruction can also take
2657<a href="#t_vector">vector</a> versions of the values in which case
2658the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2659
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2660<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2661
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2662<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2663<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2664values. Both arguments must have identical types.</p>
2665
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2666<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2667
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2668<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2669has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2670operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2671a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2672 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2673Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2674please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2675Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2676<p>Note that signed integer remainder and unsigned integer remainder are
2677distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2678<p>Taking the remainder of a division by zero leads to undefined behavior.
2679Overflow also leads to undefined behavior; this is a rare case, but can occur,
2680for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2681(The remainder doesn't actually overflow, but this rule lets srem be
2682implemented using instructions that return both the result of the division
2683and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2684<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2685<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2686</pre>
2687
2688</div>
2689<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2690<div class="doc_subsubsection">
2691 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2692
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2693<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2694
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2695<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2696<pre> &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]2697</pre>
2698<h5>Overview:</h5>
2699<p>The '<tt>frem</tt>' instruction returns the remainder from the
2700division of its two operands.</p>
2701<h5>Arguments:</h5>
2702<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2703<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2704of floating point values. Both arguments must have identical types.</p>
2705
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2706<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2707
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2708<p>This instruction returns the <i>remainder</i> of a division.
2709The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2710
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2711<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2712
2713<pre>
2714 &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]2715</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2716</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2717
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2718<!-- ======================================================================= -->
2719<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2720Operations</a> </div>
2721<div class="doc_text">
2722<p>Bitwise binary operators are used to do various forms of
2723bit-twiddling in a program. They are generally very efficient
2724instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2725instructions. They require two operands of the same type, execute an operation on them,
2726and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2727</div>
2728
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2729<!-- _______________________________________________________________________ -->
2730<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2731Instruction</a> </div>
2732<div class="doc_text">
2733<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2734<pre> &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]2735</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2736
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2737<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2738
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2739<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2740the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2741
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2742<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2743
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2744<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2745 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2746type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2747
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2748<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2749
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2750<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2751where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2752equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2753If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2754corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2755
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2756<h5>Example:</h5><pre>
2757 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2758 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2759 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2760 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2761 &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]2762</pre>
2763</div>
2764<!-- _______________________________________________________________________ -->
2765<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2766Instruction</a> </div>
2767<div class="doc_text">
2768<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2769<pre> &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]2770</pre>
2771
2772<h5>Overview:</h5>
2773<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2774operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2775
2776<h5>Arguments:</h5>
2777<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2778<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2779type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2780
2781<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2782
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2783<p>This instruction always performs a logical shift right operation. The most
2784significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2785shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2786the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2787vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2788amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2789
2790<h5>Example:</h5>
2791<pre>
2792 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2793 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2794 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2795 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2796 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2797 &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]2798</pre>
2799</div>
2800
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2801<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2802<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2803Instruction</a> </div>
2804<div class="doc_text">
2805
2806<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2807<pre> &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]2808</pre>
2809
2810<h5>Overview:</h5>
2811<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2812operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2813
2814<h5>Arguments:</h5>
2815<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2816<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2817type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2818
2819<h5>Semantics:</h5>
2820<p>This instruction always performs an arithmetic shift right operation,
2821The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2822of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2823larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2824arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2825corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2826
2827<h5>Example:</h5>
2828<pre>
2829 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2830 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2831 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2832 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2833 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2834 &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]2835</pre>
2836</div>
2837
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2838<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2839<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2840Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2841
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2842<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2843
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2844<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2845
2846<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2847 &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]2848</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2849
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2850<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2851
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2852<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2853its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2854
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2855<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2856
2857<p>The two arguments to the '<tt>and</tt>' instruction must be
2858<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2859values. Both arguments must have identical types.</p>
2860
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2861<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2862<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2863<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2864<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2865<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2866 <tbody>
2867 <tr>
2868 <td>In0</td>
2869 <td>In1</td>
2870 <td>Out</td>
2871 </tr>
2872 <tr>
2873 <td>0</td>
2874 <td>0</td>
2875 <td>0</td>
2876 </tr>
2877 <tr>
2878 <td>0</td>
2879 <td>1</td>
2880 <td>0</td>
2881 </tr>
2882 <tr>
2883 <td>1</td>
2884 <td>0</td>
2885 <td>0</td>
2886 </tr>
2887 <tr>
2888 <td>1</td>
2889 <td>1</td>
2890 <td>1</td>
2891 </tr>
2892 </tbody>
2893</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2894</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2895<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2896<pre>
2897 &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]2898 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2899 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2900</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2901</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2902<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2903<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2904<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2905<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2906<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2907</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2908<h5>Overview:</h5>
2909<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2910or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2911<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2912
2913<p>The two arguments to the '<tt>or</tt>' instruction must be
2914<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2915values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2916<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2917<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2918<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2919<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2920<table border="1" cellspacing="0" cellpadding="4">
2921 <tbody>
2922 <tr>
2923 <td>In0</td>
2924 <td>In1</td>
2925 <td>Out</td>
2926 </tr>
2927 <tr>
2928 <td>0</td>
2929 <td>0</td>
2930 <td>0</td>
2931 </tr>
2932 <tr>
2933 <td>0</td>
2934 <td>1</td>
2935 <td>1</td>
2936 </tr>
2937 <tr>
2938 <td>1</td>
2939 <td>0</td>
2940 <td>1</td>
2941 </tr>
2942 <tr>
2943 <td>1</td>
2944 <td>1</td>
2945 <td>1</td>
2946 </tr>
2947 </tbody>
2948</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2949</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2950<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2951<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2952 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2953 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2954</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2955</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2956<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2957<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2958Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2959<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2960<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2961<pre> &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]2962</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2963<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2964<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2965or of its two operands. The <tt>xor</tt> is used to implement the
2966"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2967<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2968<p>The two arguments to the '<tt>xor</tt>' instruction must be
2969<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2970values. Both arguments must have identical types.</p>
2971
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2972<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2973
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2974<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2975<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2976<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2977<table border="1" cellspacing="0" cellpadding="4">
2978 <tbody>
2979 <tr>
2980 <td>In0</td>
2981 <td>In1</td>
2982 <td>Out</td>
2983 </tr>
2984 <tr>
2985 <td>0</td>
2986 <td>0</td>
2987 <td>0</td>
2988 </tr>
2989 <tr>
2990 <td>0</td>
2991 <td>1</td>
2992 <td>1</td>
2993 </tr>
2994 <tr>
2995 <td>1</td>
2996 <td>0</td>
2997 <td>1</td>
2998 </tr>
2999 <tr>
3000 <td>1</td>
3001 <td>1</td>
3002 <td>0</td>
3003 </tr>
3004 </tbody>
3005</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]3006</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3007<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3008<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3009<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
3010 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3011 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3012 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3013</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3014</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3016<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3017<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3018 <a name="vectorops">Vector Operations</a>
3019</div>
3020
3021<div class="doc_text">
3022
3023<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3024target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3025vector-specific operations needed to process vectors effectively. While LLVM
3026does directly support these vector operations, many sophisticated algorithms
3027will want to use target-specific intrinsics to take full advantage of a specific
3028target.</p>
3029
3030</div>
3031
3032<!-- _______________________________________________________________________ -->
3033<div class="doc_subsubsection">
3034 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3035</div>
3036
3037<div class="doc_text">
3038
3039<h5>Syntax:</h5>
3040
3041<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3042 &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]3043</pre>
3044
3045<h5>Overview:</h5>
3046
3047<p>
3048The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3049element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3050</p>
3051
3052
3053<h5>Arguments:</h5>
3054
3055<p>
3056The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3057value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3058an index indicating the position from which to extract the element.
3059The index may be a variable.</p>
3060
3061<h5>Semantics:</h5>
3062
3063<p>
3064The result is a scalar of the same type as the element type of
3065<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3066<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3067results are undefined.
3068</p>
3069
3070<h5>Example:</h5>
3071
3072<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3073 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3074</pre>
3075</div>
3076
3077
3078<!-- _______________________________________________________________________ -->
3079<div class="doc_subsubsection">
3080 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3081</div>
3082
3083<div class="doc_text">
3084
3085<h5>Syntax:</h5>
3086
3087<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3088 &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]3089</pre>
3090
3091<h5>Overview:</h5>
3092
3093<p>
3094The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3095element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3096</p>
3097
3098
3099<h5>Arguments:</h5>
3100
3101<p>
3102The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3103value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3104scalar value whose type must equal the element type of the first
3105operand. The third operand is an index indicating the position at
3106which to insert the value. The index may be a variable.</p>
3107
3108<h5>Semantics:</h5>
3109
3110<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3111The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3112element values are those of <tt>val</tt> except at position
3113<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3114exceeds the length of <tt>val</tt>, the results are undefined.
3115</p>
3116
3117<h5>Example:</h5>
3118
3119<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3120 %result = 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]3121</pre>
3122</div>
3123
3124<!-- _______________________________________________________________________ -->
3125<div class="doc_subsubsection">
3126 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3127</div>
3128
3129<div class="doc_text">
3130
3131<h5>Syntax:</h5>
3132
3133<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3134 &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]3135</pre>
3136
3137<h5>Overview:</h5>
3138
3139<p>
3140The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3141from two input vectors, returning a vector with the same element type as
3142the input and length that is the same as the shuffle mask.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3143</p>
3144
3145<h5>Arguments:</h5>
3146
3147<p>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3148The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3149with types that match each other. The third argument is a shuffle mask whose
3150element type is always 'i32'. The result of the instruction is a vector whose
3151length is the same as the shuffle mask and whose element type is the same as
3152the element type of the first two operands.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3153</p>
3154
3155<p>
3156The shuffle mask operand is required to be a constant vector with either
3157constant integer or undef values.
3158</p>
3159
3160<h5>Semantics:</h5>
3161
3162<p>
3163The elements of the two input vectors are numbered from left to right across
3164both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3165the result vector, which element of the two input vectors the result element
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3166gets. The element selector may be undef (meaning "don't care") and the second
3167operand may be undef if performing a shuffle from only one vector.
3168</p>
3169
3170<h5>Example:</h5>
3171
3172<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3173 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3174 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3175 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3176 &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.
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3177 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3178 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3179 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3180 &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]3181</pre>
3182</div>
3183
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3184
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3185<!-- ======================================================================= -->
3186<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3187 <a name="aggregateops">Aggregate Operations</a>
3188</div>
3189
3190<div class="doc_text">
3191
3192<p>LLVM supports several instructions for working with aggregate values.
3193</p>
3194
3195</div>
3196
3197<!-- _______________________________________________________________________ -->
3198<div class="doc_subsubsection">
3199 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3200</div>
3201
3202<div class="doc_text">
3203
3204<h5>Syntax:</h5>
3205
3206<pre>
3207 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3208</pre>
3209
3210<h5>Overview:</h5>
3211
3212<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3213The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3214or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3215</p>
3216
3217
3218<h5>Arguments:</h5>
3219
3220<p>
3221The first operand of an '<tt>extractvalue</tt>' instruction is a
3222value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3223type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3224in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3225'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3226</p>
3227
3228<h5>Semantics:</h5>
3229
3230<p>
3231The result is the value at the position in the aggregate specified by
3232the index operands.
3233</p>
3234
3235<h5>Example:</h5>
3236
3237<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3238 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3239</pre>
3240</div>
3241
3242
3243<!-- _______________________________________________________________________ -->
3244<div class="doc_subsubsection">
3245 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3246</div>
3247
3248<div class="doc_text">
3249
3250<h5>Syntax:</h5>
3251
3252<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3253 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3254</pre>
3255
3256<h5>Overview:</h5>
3257
3258<p>
3259The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3260into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3261</p>
3262
3263
3264<h5>Arguments:</h5>
3265
3266<p>
3267The first operand of an '<tt>insertvalue</tt>' instruction is a
3268value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3269The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3270The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3271indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3272indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3273'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3274The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3275by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3276</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3277
3278<h5>Semantics:</h5>
3279
3280<p>
3281The result is an aggregate of the same type as <tt>val</tt>. Its
3282value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3283specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3284</p>
3285
3286<h5>Example:</h5>
3287
3288<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3289 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3290</pre>
3291</div>
3292
3293
3294<!-- ======================================================================= -->
3295<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3296 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3297</div>
3298
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3299<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3300
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3301<p>A key design point of an SSA-based representation is how it
3302represents memory. In LLVM, no memory locations are in SSA form, which
3303makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3304allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3305
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3306</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3307
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3308<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3309<div class="doc_subsubsection">
3310 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3311</div>
3312
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3313<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3314
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3315<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3316
3317<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3318 &lt;result&gt; = malloc &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]3319</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3321<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3322
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3323<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3324heap and returns a pointer to it. The object is always allocated in the generic
3325address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3328
3329<p>The '<tt>malloc</tt>' instruction allocates
3330<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3331bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3332appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3333number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3334If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3335be aligned to at least that boundary. If not specified, or if zero, the target can
3336choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3337
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3338<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3339
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3340<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3341
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3342<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]3343a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3344result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3345
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3346<h5>Example:</h5>
3347
3348<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3349 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3350
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3351 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3352 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3353 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3354 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3355 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3356</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3357
3358<p>Note that the code generator does not yet respect the
3359 alignment value.</p>
3360
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3361</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3363<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3364<div class="doc_subsubsection">
3365 <a name="i_free">'<tt>free</tt>' Instruction</a>
3366</div>
3367
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3368<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3370<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3371
3372<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3373 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3374</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3377
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3378<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3379memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3380
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3382
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3383<p>'<tt>value</tt>' shall be a pointer value that points to a value
3384that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3385instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3386
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3387<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3388
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3389<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3390after this instruction executes. If the pointer is null, the operation
3391is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3393<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3394
3395<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3396 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3397 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3398</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3399</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3400
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3401<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3402<div class="doc_subsubsection">
3403 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3404</div>
3405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3406<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3407
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3408<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3409
3410<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3411 &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]3412</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3413
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3414<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3415
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3416<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3417currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3418returns to its caller. The object is always allocated in the generic address
3419space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3420
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3421<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3422
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3423<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3424bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3425appropriate type to the program. If "NumElements" is specified, it is the
3426number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3427If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3428to be aligned to at least that boundary. If not specified, or if zero, the target
3429can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3430
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3431<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3432
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3433<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3434
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3435<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3436there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3437memory is automatically released when the function returns. The '<tt>alloca</tt>'
3438instruction is commonly used to represent automatic variables that must
3439have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3440 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3441instructions), the memory is reclaimed. Allocating zero bytes
3442is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3443
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3444<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3445
3446<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3447 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3448 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3449 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3450 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3451</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3452</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3453
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3454<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3455<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3456Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3457<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3458<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3459<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3460<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3461<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3462<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3463<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3464address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3465 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3466marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3467the number or order of execution of this <tt>load</tt> with other
3468volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3469instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3470<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3471The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3472(that is, the alignment of the memory address). A value of 0 or an
3473omitted "align" argument means that the operation has the preferential
3474alignment for the target. It is the responsibility of the code emitter
3475to ensure that the alignment information is correct. Overestimating
3476the alignment results in an undefined behavior. Underestimating the
3477alignment may produce less efficient code. An alignment of 1 is always
3478safe.
3479</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3480<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3481<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3482<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3483<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3484 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3485 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3486 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3487</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3488</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3489<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3490<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3491Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3492<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3493<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3494<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3495 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3496</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3497<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3498<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3499<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3500<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3501to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3502operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3503of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3504operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3505optimizer is not allowed to modify the number or order of execution of
3506this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3507 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3508<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3509The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3510(that is, the alignment of the memory address). A value of 0 or an
3511omitted "align" argument means that the operation has the preferential
3512alignment for the target. It is the responsibility of the code emitter
3513to ensure that the alignment information is correct. Overestimating
3514the alignment results in an undefined behavior. Underestimating the
3515alignment may produce less efficient code. An alignment of 1 is always
3516safe.
3517</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3518<h5>Semantics:</h5>
3519<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3520at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3521<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3522<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3523 store i32 3, i32* %ptr <i>; yields {void}</i>
3524 %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]3525</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3526</div>
3527
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3528<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3529<div class="doc_subsubsection">
3530 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3531</div>
3532
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3533<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3534<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3535<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3536 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3537</pre>
3538
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3539<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3540
3541<p>
3542The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3543subelement of an aggregate data structure. It performs address calculation only
3544and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3545
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3546<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3547
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3548<p>The first argument is always a pointer, and forms the basis of the
3549calculation. The remaining arguments are indices, that indicate which of the
3550elements of the aggregate object are indexed. The interpretation of each index
3551is dependent on the type being indexed into. The first index always indexes the
3552pointer value given as the first argument, the second index indexes a value of
3553the type pointed to (not necessarily the value directly pointed to, since the
3554first index can be non-zero), etc. The first type indexed into must be a pointer
3555value, subsequent types can be arrays, vectors and structs. Note that subsequent
3556types being indexed into can never be pointers, since that would require loading
3557the pointer before continuing calculation.</p>
3558
3559<p>The type of each index argument depends on the type it is indexing into.
3560When indexing into a (packed) structure, only <tt>i32</tt> integer
3561<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3562only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3563will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3564
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3565<p>For example, let's consider a C code fragment and how it gets
3566compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3567
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3568<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3569<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3570struct RT {
3571 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3572 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3573 char C;
3574};
3575struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3576 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3577 double Y;
3578 struct RT Z;
3579};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3580
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3581int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3582 return &amp;s[1].Z.B[5][13];
3583}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3584</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3585</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3586
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3587<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3588
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3589<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3590<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3591%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3592%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3593
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3594define i32* %foo(%ST* %s) {
3595entry:
3596 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3597 ret i32* %reg
3598}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3599</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3600</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3601
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3602<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3603
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3604<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3605type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3606}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3607the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3608i8 }</tt>' type, another structure. The third index indexes into the second
3609element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3610array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3611'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3612to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3613
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3614<p>Note that it is perfectly legal to index partially through a
3615structure, returning a pointer to an inner element. Because of this,
3616the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3617
3618<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3619 define i32* %foo(%ST* %s) {
3620 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3621 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3622 %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]3623 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3624 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3625 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3626 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3627</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3628
3629<p>Note that it is undefined to access an array out of bounds: array and
3630pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3631The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3632defined to be accessible as variable length arrays, which requires access
3633beyond the zero'th element.</p>
3634
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3635<p>The getelementptr instruction is often confusing. For some more insight
3636into how it works, see <a href="GetElementPtr.html">the getelementptr
3637FAQ</a>.</p>
3638
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3639<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3640
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3641<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3642 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3643 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3644 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3645 %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]3646 <i>; yields i8*:eptr</i>
3647 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3648</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3649</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3650
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3651<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3652<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3653</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3654<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3655<p>The instructions in this category are the conversion instructions (casting)
3656which all take a single operand and a type. They perform various bit conversions
3657on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3658</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3659
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3660<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3661<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3662 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3663</div>
3664<div class="doc_text">
3665
3666<h5>Syntax:</h5>
3667<pre>
3668 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3669</pre>
3670
3671<h5>Overview:</h5>
3672<p>
3673The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3674</p>
3675
3676<h5>Arguments:</h5>
3677<p>
3678The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3679be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3680and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3681type. The bit size of <tt>value</tt> must be larger than the bit size of
3682<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3683
3684<h5>Semantics:</h5>
3685<p>
3686The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3687and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3688larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3689It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3690
3691<h5>Example:</h5>
3692<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3693 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3694 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3695 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3696</pre>
3697</div>
3698
3699<!-- _______________________________________________________________________ -->
3700<div class="doc_subsubsection">
3701 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3702</div>
3703<div class="doc_text">
3704
3705<h5>Syntax:</h5>
3706<pre>
3707 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3708</pre>
3709
3710<h5>Overview:</h5>
3711<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3712<tt>ty2</tt>.</p>
3713
3714
3715<h5>Arguments:</h5>
3716<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3717<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3718also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3719<tt>value</tt> must be smaller than the bit size of the destination type,
3720<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3721
3722<h5>Semantics:</h5>
3723<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerc87f3df2007-05-24 19:13:27 +0000[diff] [blame]3724bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3725
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3726<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]3727
3728<h5>Example:</h5>
3729<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3730 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3731 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3732</pre>
3733</div>
3734
3735<!-- _______________________________________________________________________ -->
3736<div class="doc_subsubsection">
3737 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3738</div>
3739<div class="doc_text">
3740
3741<h5>Syntax:</h5>
3742<pre>
3743 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3744</pre>
3745
3746<h5>Overview:</h5>
3747<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3748
3749<h5>Arguments:</h5>
3750<p>
3751The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3752<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3753also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3754<tt>value</tt> must be smaller than the bit size of the destination type,
3755<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3756
3757<h5>Semantics:</h5>
3758<p>
3759The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3760bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerc87f3df2007-05-24 19:13:27 +0000[diff] [blame]3761the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3762
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3763<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]3764
3765<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3766<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3767 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3768 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3769</pre>
3770</div>
3771
3772<!-- _______________________________________________________________________ -->
3773<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3774 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3775</div>
3776
3777<div class="doc_text">
3778
3779<h5>Syntax:</h5>
3780
3781<pre>
3782 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3783</pre>
3784
3785<h5>Overview:</h5>
3786<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3787<tt>ty2</tt>.</p>
3788
3789
3790<h5>Arguments:</h5>
3791<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3792 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3793cast it to. The size of <tt>value</tt> must be larger than the size of
3794<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3795<i>no-op cast</i>.</p>
3796
3797<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3798<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3799<a href="#t_floating">floating point</a> type to a smaller
3800<a href="#t_floating">floating point</a> type. If the value cannot fit within
3801the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3802
3803<h5>Example:</h5>
3804<pre>
3805 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3806 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3807</pre>
3808</div>
3809
3810<!-- _______________________________________________________________________ -->
3811<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3812 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3813</div>
3814<div class="doc_text">
3815
3816<h5>Syntax:</h5>
3817<pre>
3818 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3819</pre>
3820
3821<h5>Overview:</h5>
3822<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3823floating point value.</p>
3824
3825<h5>Arguments:</h5>
3826<p>The '<tt>fpext</tt>' instruction takes a
3827<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3828and a <a href="#t_floating">floating point</a> type to cast it to. The source
3829type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3830
3831<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3832<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3833<a href="#t_floating">floating point</a> type to a larger
3834<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3835used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3836<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]3837
3838<h5>Example:</h5>
3839<pre>
3840 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3841 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3842</pre>
3843</div>
3844
3845<!-- _______________________________________________________________________ -->
3846<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3847 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3848</div>
3849<div class="doc_text">
3850
3851<h5>Syntax:</h5>
3852<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3853 &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]3854</pre>
3855
3856<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3857<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3858unsigned integer equivalent of type <tt>ty2</tt>.
3859</p>
3860
3861<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3862<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3863scalar or vector <a href="#t_floating">floating point</a> value, and a type
3864to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3865type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3866vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3867
3868<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3869<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3870<a href="#t_floating">floating point</a> operand into the nearest (rounding
3871towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3872the results are undefined.</p>
3873
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3874<h5>Example:</h5>
3875<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3876 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3877 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3878 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3879</pre>
3880</div>
3881
3882<!-- _______________________________________________________________________ -->
3883<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3884 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3885</div>
3886<div class="doc_text">
3887
3888<h5>Syntax:</h5>
3889<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3890 &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]3891</pre>
3892
3893<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3894<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3895<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3896</p>
3897
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3898<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3899<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3900scalar or vector <a href="#t_floating">floating point</a> value, and a type
3901to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3902type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3903vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3904
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3905<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3906<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3907<a href="#t_floating">floating point</a> operand into the nearest (rounding
3908towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3909the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3910
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3911<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3912<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3913 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3914 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3915 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3916</pre>
3917</div>
3918
3919<!-- _______________________________________________________________________ -->
3920<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3921 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3922</div>
3923<div class="doc_text">
3924
3925<h5>Syntax:</h5>
3926<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3927 &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]3928</pre>
3929
3930<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3931<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3932integer and converts that value to the <tt>ty2</tt> type.</p>
3933
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3934<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3935<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3936scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3937to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3938type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3939floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3940
3941<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3942<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3943integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3944the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3945
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3946<h5>Example:</h5>
3947<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3948 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3949 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3950</pre>
3951</div>
3952
3953<!-- _______________________________________________________________________ -->
3954<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3955 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3956</div>
3957<div class="doc_text">
3958
3959<h5>Syntax:</h5>
3960<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3961 &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]3962</pre>
3963
3964<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3965<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3966integer and converts that value to the <tt>ty2</tt> type.</p>
3967
3968<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3969<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3970scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3971to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3972type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3973floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3974
3975<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3976<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3977integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3978the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3979
3980<h5>Example:</h5>
3981<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3982 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3983 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3984</pre>
3985</div>
3986
3987<!-- _______________________________________________________________________ -->
3988<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3989 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3990</div>
3991<div class="doc_text">
3992
3993<h5>Syntax:</h5>
3994<pre>
3995 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3996</pre>
3997
3998<h5>Overview:</h5>
3999<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4000the integer type <tt>ty2</tt>.</p>
4001
4002<h5>Arguments:</h5>
4003<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4004must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4005<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]4006
4007<h5>Semantics:</h5>
4008<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
4009<tt>ty2</tt> by interpreting the pointer value as an integer and either
4010truncating or zero extending that value to the size of the integer type. If
4011<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4012<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4013are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4014change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4015
4016<h5>Example:</h5>
4017<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4018 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4019 %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]4020</pre>
4021</div>
4022
4023<!-- _______________________________________________________________________ -->
4024<div class="doc_subsubsection">
4025 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4026</div>
4027<div class="doc_text">
4028
4029<h5>Syntax:</h5>
4030<pre>
4031 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4032</pre>
4033
4034<h5>Overview:</h5>
4035<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4036a pointer type, <tt>ty2</tt>.</p>
4037
4038<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4039<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4040value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4041<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4042
4043<h5>Semantics:</h5>
4044<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4045<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4046the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4047size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4048the size of a pointer then a zero extension is done. If they are the same size,
4049nothing is done (<i>no-op cast</i>).</p>
4050
4051<h5>Example:</h5>
4052<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4053 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4054 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4055 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4056</pre>
4057</div>
4058
4059<!-- _______________________________________________________________________ -->
4060<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4061 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4062</div>
4063<div class="doc_text">
4064
4065<h5>Syntax:</h5>
4066<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4067 &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]4068</pre>
4069
4070<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4071
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4072<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4073<tt>ty2</tt> without changing any bits.</p>
4074
4075<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4076
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4077<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]4078a non-aggregate first class value, and a type to cast it to, which must also be
4079a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4080<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]4081and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4082type is a pointer, the destination type must also be a pointer. This
4083instruction supports bitwise conversion of vectors to integers and to vectors
4084of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4085
4086<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4087<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4088<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4089this conversion. The conversion is done as if the <tt>value</tt> had been
4090stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4091converted to other pointer types with this instruction. To convert pointers to
4092other types, use the <a href="#i_inttoptr">inttoptr</a> or
4093<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4094
4095<h5>Example:</h5>
4096<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4097 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4098 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4099 %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]4100</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4101</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4102
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4103<!-- ======================================================================= -->
4104<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4105<div class="doc_text">
4106<p>The instructions in this category are the "miscellaneous"
4107instructions, which defy better classification.</p>
4108</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4109
4110<!-- _______________________________________________________________________ -->
4111<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4112</div>
4113<div class="doc_text">
4114<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4115<pre> &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]4116</pre>
4117<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4118<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4119a vector of boolean values based on comparison
4120of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4121<h5>Arguments:</h5>
4122<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4123the condition code indicating the kind of comparison to perform. It is not
4124a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4125</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4126<ol>
4127 <li><tt>eq</tt>: equal</li>
4128 <li><tt>ne</tt>: not equal </li>
4129 <li><tt>ugt</tt>: unsigned greater than</li>
4130 <li><tt>uge</tt>: unsigned greater or equal</li>
4131 <li><tt>ult</tt>: unsigned less than</li>
4132 <li><tt>ule</tt>: unsigned less or equal</li>
4133 <li><tt>sgt</tt>: signed greater than</li>
4134 <li><tt>sge</tt>: signed greater or equal</li>
4135 <li><tt>slt</tt>: signed less than</li>
4136 <li><tt>sle</tt>: signed less or equal</li>
4137</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4138<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4139<a href="#t_pointer">pointer</a>
4140or integer <a href="#t_vector">vector</a> typed.
4141They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4142<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4143<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4144the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4145yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4146</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4147<ol>
4148 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4149 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4150 </li>
4151 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4152 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4153 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4154 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4155 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4156 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4157 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4158 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4159 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4160 <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]4161 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4162 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4163 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4164 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4165 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4166 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4167 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4168 <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]4169</ol>
4170<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4171values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4172<p>If the operands are integer vectors, then they are compared
4173element by element. The result is an <tt>i1</tt> vector with
4174the same number of elements as the values being compared.
4175Otherwise, the result is an <tt>i1</tt>.
4176</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4177
4178<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4179<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4180 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4181 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4182 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4183 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4184 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4185</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4186
4187<p>Note that the code generator does not yet support vector types with
4188 the <tt>icmp</tt> instruction.</p>
4189
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4190</div>
4191
4192<!-- _______________________________________________________________________ -->
4193<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4194</div>
4195<div class="doc_text">
4196<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4197<pre> &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]4198</pre>
4199<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4200<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4201or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4202of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4203<p>
4204If the operands are floating point scalars, then the result
4205type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4206</p>
4207<p>If the operands are floating point vectors, then the result type
4208is a vector of boolean with the same number of elements as the
4209operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4210<h5>Arguments:</h5>
4211<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4212the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4213a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4214<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4215 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4216 <li><tt>oeq</tt>: ordered and equal</li>
4217 <li><tt>ogt</tt>: ordered and greater than </li>
4218 <li><tt>oge</tt>: ordered and greater than or equal</li>
4219 <li><tt>olt</tt>: ordered and less than </li>
4220 <li><tt>ole</tt>: ordered and less than or equal</li>
4221 <li><tt>one</tt>: ordered and not equal</li>
4222 <li><tt>ord</tt>: ordered (no nans)</li>
4223 <li><tt>ueq</tt>: unordered or equal</li>
4224 <li><tt>ugt</tt>: unordered or greater than </li>
4225 <li><tt>uge</tt>: unordered or greater than or equal</li>
4226 <li><tt>ult</tt>: unordered or less than </li>
4227 <li><tt>ule</tt>: unordered or less than or equal</li>
4228 <li><tt>une</tt>: unordered or not equal</li>
4229 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4230 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4231</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4232<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4233<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4234<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4235either a <a href="#t_floating">floating point</a> type
4236or a <a href="#t_vector">vector</a> of floating point type.
4237They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4238<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4239<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4240according to the condition code given as <tt>cond</tt>.
4241If the operands are vectors, then the vectors are compared
4242element by element.
4243Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4244always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4245<ol>
4246 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4247 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4248 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4249 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4250 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4251 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4252 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4253 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4254 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4255 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4256 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4257 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4258 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4259 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4260 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4261 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4262 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4263 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4264 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4265 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4266 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4267 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4268 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4269 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4270 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4271 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4272 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4273 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4274</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4275
4276<h5>Example:</h5>
4277<pre> &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]4278 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4279 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4280 &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]4281</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4282
4283<p>Note that the code generator does not yet support vector types with
4284 the <tt>fcmp</tt> instruction.</p>
4285
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4286</div>
4287
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4288<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4289<div class="doc_subsubsection">
4290 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4291</div>
4292<div class="doc_text">
4293<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4294<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4295</pre>
4296<h5>Overview:</h5>
4297<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4298element-wise comparison of its two integer vector operands.</p>
4299<h5>Arguments:</h5>
4300<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4301the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4302a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4303<ol>
4304 <li><tt>eq</tt>: equal</li>
4305 <li><tt>ne</tt>: not equal </li>
4306 <li><tt>ugt</tt>: unsigned greater than</li>
4307 <li><tt>uge</tt>: unsigned greater or equal</li>
4308 <li><tt>ult</tt>: unsigned less than</li>
4309 <li><tt>ule</tt>: unsigned less or equal</li>
4310 <li><tt>sgt</tt>: signed greater than</li>
4311 <li><tt>sge</tt>: signed greater or equal</li>
4312 <li><tt>slt</tt>: signed less than</li>
4313 <li><tt>sle</tt>: signed less or equal</li>
4314</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4315<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4316<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4317<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4318<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4319according to the condition code given as <tt>cond</tt>. The comparison yields a
4320<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4321identical type as the values being compared. The most significant bit in each
4322element is 1 if the element-wise comparison evaluates to true, and is 0
4323otherwise. All other bits of the result are undefined. The condition codes
4324are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4325instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4326
4327<h5>Example:</h5>
4328<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4329 &lt;result&gt; = vicmp eq &lt;2 x i32&gt; &lt; i32 4, i32 0&gt;, &lt; i32 5, i32 0&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4330 &lt;result&gt; = vicmp ult &lt;2 x i8 &gt; &lt; i8 1, i8 2&gt;, &lt; i8 2, i8 2 &gt; <i>; yields: result=&lt;2 x i8&gt; &lt; i8 -1, i8 0 &gt;</i>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4331</pre>
4332</div>
4333
4334<!-- _______________________________________________________________________ -->
4335<div class="doc_subsubsection">
4336 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4337</div>
4338<div class="doc_text">
4339<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4340<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4341<h5>Overview:</h5>
4342<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4343element-wise comparison of its two floating point vector operands. The output
4344elements have the same width as the input elements.</p>
4345<h5>Arguments:</h5>
4346<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4347the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4348a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4349<ol>
4350 <li><tt>false</tt>: no comparison, always returns false</li>
4351 <li><tt>oeq</tt>: ordered and equal</li>
4352 <li><tt>ogt</tt>: ordered and greater than </li>
4353 <li><tt>oge</tt>: ordered and greater than or equal</li>
4354 <li><tt>olt</tt>: ordered and less than </li>
4355 <li><tt>ole</tt>: ordered and less than or equal</li>
4356 <li><tt>one</tt>: ordered and not equal</li>
4357 <li><tt>ord</tt>: ordered (no nans)</li>
4358 <li><tt>ueq</tt>: unordered or equal</li>
4359 <li><tt>ugt</tt>: unordered or greater than </li>
4360 <li><tt>uge</tt>: unordered or greater than or equal</li>
4361 <li><tt>ult</tt>: unordered or less than </li>
4362 <li><tt>ule</tt>: unordered or less than or equal</li>
4363 <li><tt>une</tt>: unordered or not equal</li>
4364 <li><tt>uno</tt>: unordered (either nans)</li>
4365 <li><tt>true</tt>: no comparison, always returns true</li>
4366</ol>
4367<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4368<a href="#t_floating">floating point</a> typed. They must also be identical
4369types.</p>
4370<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4371<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4372according to the condition code given as <tt>cond</tt>. The comparison yields a
4373<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4374an identical number of elements as the values being compared, and each element
4375having identical with to the width of the floating point elements. The most
4376significant bit in each element is 1 if the element-wise comparison evaluates to
4377true, and is 0 otherwise. All other bits of the result are undefined. The
4378condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4379<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4380
4381<h5>Example:</h5>
4382<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4383 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4384 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4385
4386 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4387 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4388</pre>
4389</div>
4390
4391<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4392<div class="doc_subsubsection">
4393 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4394</div>
4395
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4396<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4397
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4398<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4399
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4400<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4401<h5>Overview:</h5>
4402<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4403the SSA graph representing the function.</p>
4404<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4405
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4406<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4407field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4408as arguments, with one pair for each predecessor basic block of the
4409current block. Only values of <a href="#t_firstclass">first class</a>
4410type may be used as the value arguments to the PHI node. Only labels
4411may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4412
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4413<p>There must be no non-phi instructions between the start of a basic
4414block and the PHI instructions: i.e. PHI instructions must be first in
4415a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4416
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4417<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4418
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4419<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4420specified by the pair corresponding to the predecessor basic block that executed
4421just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4422
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4423<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4424<pre>
4425Loop: ; Infinite loop that counts from 0 on up...
4426 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4427 %nextindvar = add i32 %indvar, 1
4428 br label %Loop
4429</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4430</div>
4431
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4432<!-- _______________________________________________________________________ -->
4433<div class="doc_subsubsection">
4434 <a name="i_select">'<tt>select</tt>' Instruction</a>
4435</div>
4436
4437<div class="doc_text">
4438
4439<h5>Syntax:</h5>
4440
4441<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4442 &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>
4443
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4444 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4445</pre>
4446
4447<h5>Overview:</h5>
4448
4449<p>
4450The '<tt>select</tt>' instruction is used to choose one value based on a
4451condition, without branching.
4452</p>
4453
4454
4455<h5>Arguments:</h5>
4456
4457<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4458The '<tt>select</tt>' instruction requires an 'i1' value or
4459a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4460condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4461type. If the val1/val2 are vectors and
4462the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4463individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4464</p>
4465
4466<h5>Semantics:</h5>
4467
4468<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4469If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4470value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4471</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4472<p>
4473If the condition is a vector of i1, then the value arguments must
4474be vectors of the same size, and the selection is done element
4475by element.
4476</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4477
4478<h5>Example:</h5>
4479
4480<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4481 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4482</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4483
4484<p>Note that the code generator does not yet support conditions
4485 with vector type.</p>
4486
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4487</div>
4488
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4489
4490<!-- _______________________________________________________________________ -->
4491<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4492 <a name="i_call">'<tt>call</tt>' Instruction</a>
4493</div>
4494
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4495<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4496
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4497<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4498<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4499 &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]4500</pre>
4501
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4502<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4503
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4504<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4505
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4506<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4507
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4508<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4509
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4510<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4511 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4512 <p>The optional "tail" marker indicates whether the callee function accesses
4513 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4514 function call is eligible for tail call optimization. Note that calls may
4515 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4516 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4517 </li>
4518 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4519 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4520 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4521 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4522 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4523
4524 <li>
4525 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4526 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4527 and '<tt>inreg</tt>' attributes are valid here.</p>
4528 </li>
4529
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4530 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4531 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4532 the type of the return value. Functions that return no value are marked
4533 <tt><a href="#t_void">void</a></tt>.</p>
4534 </li>
4535 <li>
4536 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4537 value being invoked. The argument types must match the types implied by
4538 this signature. This type can be omitted if the function is not varargs
4539 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4540 </li>
4541 <li>
4542 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4543 be invoked. In most cases, this is a direct function invocation, but
4544 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4545 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4546 </li>
4547 <li>
4548 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4549 function signature argument types. All arguments must be of
4550 <a href="#t_firstclass">first class</a> type. If the function signature
4551 indicates the function accepts a variable number of arguments, the extra
4552 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4553 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4554 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4555 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4556 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4557 '<tt>readnone</tt>' attributes are valid here.</p>
4558 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4559</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4560
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4561<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4562
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4563<p>The '<tt>call</tt>' instruction is used to cause control flow to
4564transfer to a specified function, with its incoming arguments bound to
4565the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4566instruction in the called function, control flow continues with the
4567instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4568function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4569
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4570<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4571
4572<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4573 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4574 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4575 %X = tail call i32 @foo() <i>; yields i32</i>
4576 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4577 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4578
4579 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4580 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4581 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4582 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4583 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4584 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4585</pre>
4586
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4587</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4588
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4589<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4590<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4591 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4592</div>
4593
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4594<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4595
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4596<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4597
4598<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4599 &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]4600</pre>
4601
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4602<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4603
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4604<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4605the "variable argument" area of a function call. It is used to implement the
4606<tt>va_arg</tt> macro in C.</p>
4607
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4608<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4609
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4610<p>This instruction takes a <tt>va_list*</tt> value and the type of
4611the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4612increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4613actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4614
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4615<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4616
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4617<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4618type from the specified <tt>va_list</tt> and causes the
4619<tt>va_list</tt> to point to the next argument. For more information,
4620see the variable argument handling <a href="#int_varargs">Intrinsic
4621Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4622
4623<p>It is legal for this instruction to be called in a function which does not
4624take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4625function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4626
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4627<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4628href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4629argument.</p>
4630
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4631<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4632
4633<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4634
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]4635<p>Note that the code generator does not yet fully support va_arg
4636 on many targets. Also, it does not currently support va_arg with
4637 aggregate types on any target.</p>
4638
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4639</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4640
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4641<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4642<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4643<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4644
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4645<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4646
4647<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4648well known names and semantics and are required to follow certain restrictions.
4649Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4650language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4651adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4652
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4653<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4654prefix is reserved in LLVM for intrinsic names; thus, function names may not
4655begin with this prefix. Intrinsic functions must always be external functions:
4656you cannot define the body of intrinsic functions. Intrinsic functions may
4657only be used in call or invoke instructions: it is illegal to take the address
4658of an intrinsic function. Additionally, because intrinsic functions are part
4659of the LLVM language, it is required if any are added that they be documented
4660here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4661
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4662<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4663a family of functions that perform the same operation but on different data
4664types. Because LLVM can represent over 8 million different integer types,
4665overloading is used commonly to allow an intrinsic function to operate on any
4666integer type. One or more of the argument types or the result type can be
4667overloaded to accept any integer type. Argument types may also be defined as
4668exactly matching a previous argument's type or the result type. This allows an
4669intrinsic function which accepts multiple arguments, but needs all of them to
4670be of the same type, to only be overloaded with respect to a single argument or
4671the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4672
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4673<p>Overloaded intrinsics will have the names of its overloaded argument types
4674encoded into its function name, each preceded by a period. Only those types
4675which are overloaded result in a name suffix. Arguments whose type is matched
4676against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4677take an integer of any width and returns an integer of exactly the same integer
4678width. This leads to a family of functions such as
4679<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4680Only one type, the return type, is overloaded, and only one type suffix is
4681required. Because the argument's type is matched against the return type, it
4682does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4683
4684<p>To learn how to add an intrinsic function, please see the
4685<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4686</p>
4687
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4688</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4689
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4690<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4691<div class="doc_subsection">
4692 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4693</div>
4694
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4695<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4696
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4697<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4698 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4699intrinsic functions. These functions are related to the similarly
4700named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4701
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4702<p>All of these functions operate on arguments that use a
4703target-specific value type "<tt>va_list</tt>". The LLVM assembly
4704language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4705transformations should be prepared to handle these functions regardless of
4706the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4707
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4708<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4709instruction and the variable argument handling intrinsic functions are
4710used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4711
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4712<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4713<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4714define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4715 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4716 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4717 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4718 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4719
4720 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4721 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4722
4723 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4724 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4725 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4726 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4727 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4728
4729 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4730 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4731 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4732}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4733
4734declare void @llvm.va_start(i8*)
4735declare void @llvm.va_copy(i8*, i8*)
4736declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4737</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4738</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4739
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4740</div>
4741
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4742<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4743<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4744 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4745</div>
4746
4747
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4748<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4749<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4750<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4751<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4752<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4753<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4754href="#i_va_arg">va_arg</a></tt>.</p>
4755
4756<h5>Arguments:</h5>
4757
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4758<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]4759
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4760<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4761
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4762<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4763macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4764<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4765<tt>va_arg</tt> will produce the first variable argument passed to the function.
4766Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4767last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4768
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4769</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4770
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4771<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4772<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4773 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4774</div>
4775
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4776<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4777<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4778<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4779<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4780
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4781<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4782which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4783or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4784
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4785<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4786
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4787<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]4788
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4789<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4790
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4791<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4792macro available in C. In a target-dependent way, it destroys the
4793<tt>va_list</tt> element to which the argument points. Calls to <a
4794href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4795<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4796<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4797
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4798</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4799
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4800<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4801<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4802 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4803</div>
4804
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4805<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4806
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4807<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4808
4809<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4810 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4811</pre>
4812
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4813<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4814
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4815<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4816from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4817
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4818<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4819
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4820<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth5305ea52005-06-22 20:38:11 +0000[diff] [blame]4821The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4822
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4823
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4824<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4825
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4826<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4827macro available in C. In a target-dependent way, it copies the source
4828<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4829intrinsic is necessary because the <tt><a href="#int_va_start">
4830llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4831example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4832
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4833</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4834
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4835<!-- ======================================================================= -->
4836<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4837 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4838</div>
4839
4840<div class="doc_text">
4841
4842<p>
4843LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4844Collection</a> (GC) requires the implementation and generation of these
4845intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4846These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4847stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4848href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4849Front-ends for type-safe garbage collected languages should generate these
4850intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4851href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4852</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4853
4854<p>The garbage collection intrinsics only operate on objects in the generic
4855 address space (address space zero).</p>
4856
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4857</div>
4858
4859<!-- _______________________________________________________________________ -->
4860<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4861 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4862</div>
4863
4864<div class="doc_text">
4865
4866<h5>Syntax:</h5>
4867
4868<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4869 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4870</pre>
4871
4872<h5>Overview:</h5>
4873
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4874<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4875the code generator, and allows some metadata to be associated with it.</p>
4876
4877<h5>Arguments:</h5>
4878
4879<p>The first argument specifies the address of a stack object that contains the
4880root pointer. The second pointer (which must be either a constant or a global
4881value address) contains the meta-data to be associated with the root.</p>
4882
4883<h5>Semantics:</h5>
4884
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4885<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4886location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4887the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4888intrinsic may only be used in a function which <a href="#gc">specifies a GC
4889algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4890
4891</div>
4892
4893
4894<!-- _______________________________________________________________________ -->
4895<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4896 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4897</div>
4898
4899<div class="doc_text">
4900
4901<h5>Syntax:</h5>
4902
4903<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4904 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4905</pre>
4906
4907<h5>Overview:</h5>
4908
4909<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4910locations, allowing garbage collector implementations that require read
4911barriers.</p>
4912
4913<h5>Arguments:</h5>
4914
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4915<p>The second argument is the address to read from, which should be an address
4916allocated from the garbage collector. The first object is a pointer to the
4917start of the referenced object, if needed by the language runtime (otherwise
4918null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4919
4920<h5>Semantics:</h5>
4921
4922<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4923instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4924garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4925may only be used in a function which <a href="#gc">specifies a GC
4926algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4927
4928</div>
4929
4930
4931<!-- _______________________________________________________________________ -->
4932<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4933 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4934</div>
4935
4936<div class="doc_text">
4937
4938<h5>Syntax:</h5>
4939
4940<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4941 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4942</pre>
4943
4944<h5>Overview:</h5>
4945
4946<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4947locations, allowing garbage collector implementations that require write
4948barriers (such as generational or reference counting collectors).</p>
4949
4950<h5>Arguments:</h5>
4951
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4952<p>The first argument is the reference to store, the second is the start of the
4953object to store it to, and the third is the address of the field of Obj to
4954store to. If the runtime does not require a pointer to the object, Obj may be
4955null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4956
4957<h5>Semantics:</h5>
4958
4959<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4960instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4961garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4962may only be used in a function which <a href="#gc">specifies a GC
4963algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4964
4965</div>
4966
4967
4968
4969<!-- ======================================================================= -->
4970<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4971 <a name="int_codegen">Code Generator Intrinsics</a>
4972</div>
4973
4974<div class="doc_text">
4975<p>
4976These intrinsics are provided by LLVM to expose special features that may only
4977be implemented with code generator support.
4978</p>
4979
4980</div>
4981
4982<!-- _______________________________________________________________________ -->
4983<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4984 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4985</div>
4986
4987<div class="doc_text">
4988
4989<h5>Syntax:</h5>
4990<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4991 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4992</pre>
4993
4994<h5>Overview:</h5>
4995
4996<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4997The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4998target-specific value indicating the return address of the current function
4999or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5000</p>
5001
5002<h5>Arguments:</h5>
5003
5004<p>
5005The argument to this intrinsic indicates which function to return the address
5006for. Zero indicates the calling function, one indicates its caller, etc. The
5007argument is <b>required</b> to be a constant integer value.
5008</p>
5009
5010<h5>Semantics:</h5>
5011
5012<p>
5013The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
5014the return address of the specified call frame, or zero if it cannot be
5015identified. The value returned by this intrinsic is likely to be incorrect or 0
5016for arguments other than zero, so it should only be used for debugging purposes.
5017</p>
5018
5019<p>
5020Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]5021aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5022source-language caller.
5023</p>
5024</div>
5025
5026
5027<!-- _______________________________________________________________________ -->
5028<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5029 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5030</div>
5031
5032<div class="doc_text">
5033
5034<h5>Syntax:</h5>
5035<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5036 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5037</pre>
5038
5039<h5>Overview:</h5>
5040
5041<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]5042The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5043target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5044</p>
5045
5046<h5>Arguments:</h5>
5047
5048<p>
5049The argument to this intrinsic indicates which function to return the frame
5050pointer for. Zero indicates the calling function, one indicates its caller,
5051etc. The argument is <b>required</b> to be a constant integer value.
5052</p>
5053
5054<h5>Semantics:</h5>
5055
5056<p>
5057The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5058the frame address of the specified call frame, or zero if it cannot be
5059identified. The value returned by this intrinsic is likely to be incorrect or 0
5060for arguments other than zero, so it should only be used for debugging purposes.
5061</p>
5062
5063<p>
5064Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]5065aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5066source-language caller.
5067</p>
5068</div>
5069
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5070<!-- _______________________________________________________________________ -->
5071<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5072 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5073</div>
5074
5075<div class="doc_text">
5076
5077<h5>Syntax:</h5>
5078<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5079 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5080</pre>
5081
5082<h5>Overview:</h5>
5083
5084<p>
5085The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5086the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5087<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5088features like scoped automatic variable sized arrays in C99.
5089</p>
5090
5091<h5>Semantics:</h5>
5092
5093<p>
5094This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5095href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5096<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5097<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5098state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5099practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5100that were allocated after the <tt>llvm.stacksave</tt> was executed.
5101</p>
5102
5103</div>
5104
5105<!-- _______________________________________________________________________ -->
5106<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5107 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5108</div>
5109
5110<div class="doc_text">
5111
5112<h5>Syntax:</h5>
5113<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5114 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5115</pre>
5116
5117<h5>Overview:</h5>
5118
5119<p>
5120The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5121the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5122href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5123useful for implementing language features like scoped automatic variable sized
5124arrays in C99.
5125</p>
5126
5127<h5>Semantics:</h5>
5128
5129<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5130See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5131</p>
5132
5133</div>
5134
5135
5136<!-- _______________________________________________________________________ -->
5137<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5138 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5139</div>
5140
5141<div class="doc_text">
5142
5143<h5>Syntax:</h5>
5144<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5145 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]5146</pre>
5147
5148<h5>Overview:</h5>
5149
5150
5151<p>
5152The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5153a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5154no
5155effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]5156characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5157</p>
5158
5159<h5>Arguments:</h5>
5160
5161<p>
5162<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5163determining if the fetch should be for a read (0) or write (1), and
5164<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]5165locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5166<tt>locality</tt> arguments must be constant integers.
5167</p>
5168
5169<h5>Semantics:</h5>
5170
5171<p>
5172This intrinsic does not modify the behavior of the program. In particular,
5173prefetches cannot trap and do not produce a value. On targets that support this
5174intrinsic, the prefetch can provide hints to the processor cache for better
5175performance.
5176</p>
5177
5178</div>
5179
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5180<!-- _______________________________________________________________________ -->
5181<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5182 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5183</div>
5184
5185<div class="doc_text">
5186
5187<h5>Syntax:</h5>
5188<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5189 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5190</pre>
5191
5192<h5>Overview:</h5>
5193
5194
5195<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5196The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5197(PC) in a region of
5198code to simulators and other tools. The method is target specific, but it is
5199expected that the marker will use exported symbols to transmit the PC of the
5200marker.
5201The marker makes no guarantees that it will remain with any specific instruction
5202after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]5203optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5204correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5205</p>
5206
5207<h5>Arguments:</h5>
5208
5209<p>
5210<tt>id</tt> is a numerical id identifying the marker.
5211</p>
5212
5213<h5>Semantics:</h5>
5214
5215<p>
5216This intrinsic does not modify the behavior of the program. Backends that do not
5217support this intrinisic may ignore it.
5218</p>
5219
5220</div>
5221
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5222<!-- _______________________________________________________________________ -->
5223<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5224 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5225</div>
5226
5227<div class="doc_text">
5228
5229<h5>Syntax:</h5>
5230<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5231 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5232</pre>
5233
5234<h5>Overview:</h5>
5235
5236
5237<p>
5238The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5239counter register (or similar low latency, high accuracy clocks) on those targets
5240that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5241As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5242should only be used for small timings.
5243</p>
5244
5245<h5>Semantics:</h5>
5246
5247<p>
5248When directly supported, reading the cycle counter should not modify any memory.
5249Implementations are allowed to either return a application specific value or a
5250system wide value. On backends without support, this is lowered to a constant 0.
5251</p>
5252
5253</div>
5254
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5255<!-- ======================================================================= -->
5256<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5257 <a name="int_libc">Standard C Library Intrinsics</a>
5258</div>
5259
5260<div class="doc_text">
5261<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5262LLVM provides intrinsics for a few important standard C library functions.
5263These intrinsics allow source-language front-ends to pass information about the
5264alignment of the pointer arguments to the code generator, providing opportunity
5265for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5266</p>
5267
5268</div>
5269
5270<!-- _______________________________________________________________________ -->
5271<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5272 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5273</div>
5274
5275<div class="doc_text">
5276
5277<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5278<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5279width. Not all targets support all bit widths however.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5280<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5281 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5282 i8 &lt;len&gt;, i32 &lt;align&gt;)
5283 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5284 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5285 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5286 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5287 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5288 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5289</pre>
5290
5291<h5>Overview:</h5>
5292
5293<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5294The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5295location to the destination location.
5296</p>
5297
5298<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5299Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5300intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5301</p>
5302
5303<h5>Arguments:</h5>
5304
5305<p>
5306The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5307the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5308specifying the number of bytes to copy, and the fourth argument is the alignment
5309of the source and destination locations.
5310</p>
5311
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5312<p>
5313If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +0000[diff] [blame]5314the caller guarantees that both the source and destination pointers are aligned
5315to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5316</p>
5317
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5318<h5>Semantics:</h5>
5319
5320<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5321The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5322location to the destination location, which are not allowed to overlap. It
5323copies "len" bytes of memory over. If the argument is known to be aligned to
5324some boundary, this can be specified as the fourth argument, otherwise it should
5325be set to 0 or 1.
5326</p>
5327</div>
5328
5329
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5330<!-- _______________________________________________________________________ -->
5331<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5332 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5333</div>
5334
5335<div class="doc_text">
5336
5337<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5338<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5339width. Not all targets support all bit widths however.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5340<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5341 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5342 i8 &lt;len&gt;, i32 &lt;align&gt;)
5343 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5344 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5345 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5346 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5347 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5348 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5349</pre>
5350
5351<h5>Overview:</h5>
5352
5353<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5354The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5355location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5356'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5357</p>
5358
5359<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5360Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5361intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5362</p>
5363
5364<h5>Arguments:</h5>
5365
5366<p>
5367The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5368the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5369specifying the number of bytes to copy, and the fourth argument is the alignment
5370of the source and destination locations.
5371</p>
5372
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5373<p>
5374If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +0000[diff] [blame]5375the caller guarantees that the source and destination pointers are aligned to
5376that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5377</p>
5378
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5379<h5>Semantics:</h5>
5380
5381<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5382The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5383location to the destination location, which may overlap. It
5384copies "len" bytes of memory over. If the argument is known to be aligned to
5385some boundary, this can be specified as the fourth argument, otherwise it should
5386be set to 0 or 1.
5387</p>
5388</div>
5389
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5390
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5391<!-- _______________________________________________________________________ -->
5392<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5393 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5394</div>
5395
5396<div class="doc_text">
5397
5398<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5399<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5400width. Not all targets support all bit widths however.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5401<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5402 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5403 i8 &lt;len&gt;, i32 &lt;align&gt;)
5404 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5405 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5406 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5407 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5408 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5409 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5410</pre>
5411
5412<h5>Overview:</h5>
5413
5414<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5415The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5416byte value.
5417</p>
5418
5419<p>
5420Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5421does not return a value, and takes an extra alignment argument.
5422</p>
5423
5424<h5>Arguments:</h5>
5425
5426<p>
5427The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5428byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5429argument specifying the number of bytes to fill, and the fourth argument is the
5430known alignment of destination location.
5431</p>
5432
5433<p>
5434If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +0000[diff] [blame]5435the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5436</p>
5437
5438<h5>Semantics:</h5>
5439
5440<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5441The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5442the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5443destination location. If the argument is known to be aligned to some boundary,
5444this can be specified as the fourth argument, otherwise it should be set to 0 or
54451.
5446</p>
5447</div>
5448
5449
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5450<!-- _______________________________________________________________________ -->
5451<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5452 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5453</div>
5454
5455<div class="doc_text">
5456
5457<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5458<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5459floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5460types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5461<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5462 declare float @llvm.sqrt.f32(float %Val)
5463 declare double @llvm.sqrt.f64(double %Val)
5464 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5465 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5466 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5467</pre>
5468
5469<h5>Overview:</h5>
5470
5471<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5472The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5473returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5474<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5475negative numbers other than -0.0 (which allows for better optimization, because
5476there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5477defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5478</p>
5479
5480<h5>Arguments:</h5>
5481
5482<p>
5483The argument and return value are floating point numbers of the same type.
5484</p>
5485
5486<h5>Semantics:</h5>
5487
5488<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5489This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5490floating point number.
5491</p>
5492</div>
5493
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5494<!-- _______________________________________________________________________ -->
5495<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5496 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5497</div>
5498
5499<div class="doc_text">
5500
5501<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5502<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5503floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5504types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5505<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5506 declare float @llvm.powi.f32(float %Val, i32 %power)
5507 declare double @llvm.powi.f64(double %Val, i32 %power)
5508 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5509 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5510 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5511</pre>
5512
5513<h5>Overview:</h5>
5514
5515<p>
5516The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5517specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5518multiplications is not defined. When a vector of floating point type is
5519used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5520</p>
5521
5522<h5>Arguments:</h5>
5523
5524<p>
5525The second argument is an integer power, and the first is a value to raise to
5526that power.
5527</p>
5528
5529<h5>Semantics:</h5>
5530
5531<p>
5532This function returns the first value raised to the second power with an
5533unspecified sequence of rounding operations.</p>
5534</div>
5535
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5536<!-- _______________________________________________________________________ -->
5537<div class="doc_subsubsection">
5538 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5539</div>
5540
5541<div class="doc_text">
5542
5543<h5>Syntax:</h5>
5544<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5545floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5546types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5547<pre>
5548 declare float @llvm.sin.f32(float %Val)
5549 declare double @llvm.sin.f64(double %Val)
5550 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5551 declare fp128 @llvm.sin.f128(fp128 %Val)
5552 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5553</pre>
5554
5555<h5>Overview:</h5>
5556
5557<p>
5558The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5559</p>
5560
5561<h5>Arguments:</h5>
5562
5563<p>
5564The argument and return value are floating point numbers of the same type.
5565</p>
5566
5567<h5>Semantics:</h5>
5568
5569<p>
5570This function returns the sine of the specified operand, returning the
5571same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5572conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5573</div>
5574
5575<!-- _______________________________________________________________________ -->
5576<div class="doc_subsubsection">
5577 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5578</div>
5579
5580<div class="doc_text">
5581
5582<h5>Syntax:</h5>
5583<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5584floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5585types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5586<pre>
5587 declare float @llvm.cos.f32(float %Val)
5588 declare double @llvm.cos.f64(double %Val)
5589 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5590 declare fp128 @llvm.cos.f128(fp128 %Val)
5591 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5592</pre>
5593
5594<h5>Overview:</h5>
5595
5596<p>
5597The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5598</p>
5599
5600<h5>Arguments:</h5>
5601
5602<p>
5603The argument and return value are floating point numbers of the same type.
5604</p>
5605
5606<h5>Semantics:</h5>
5607
5608<p>
5609This function returns the cosine of the specified operand, returning the
5610same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5611conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5612</div>
5613
5614<!-- _______________________________________________________________________ -->
5615<div class="doc_subsubsection">
5616 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5617</div>
5618
5619<div class="doc_text">
5620
5621<h5>Syntax:</h5>
5622<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5623floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5624types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5625<pre>
5626 declare float @llvm.pow.f32(float %Val, float %Power)
5627 declare double @llvm.pow.f64(double %Val, double %Power)
5628 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5629 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5630 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5631</pre>
5632
5633<h5>Overview:</h5>
5634
5635<p>
5636The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5637specified (positive or negative) power.
5638</p>
5639
5640<h5>Arguments:</h5>
5641
5642<p>
5643The second argument is a floating point power, and the first is a value to
5644raise to that power.
5645</p>
5646
5647<h5>Semantics:</h5>
5648
5649<p>
5650This function returns the first value raised to the second power,
5651returning the
5652same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5653conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5654</div>
5655
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5656
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5657<!-- ======================================================================= -->
5658<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5659 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5660</div>
5661
5662<div class="doc_text">
5663<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5664LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5665These allow efficient code generation for some algorithms.
5666</p>
5667
5668</div>
5669
5670<!-- _______________________________________________________________________ -->
5671<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5672 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5673</div>
5674
5675<div class="doc_text">
5676
5677<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5678<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5679type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5680<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5681 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5682 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5683 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5684</pre>
5685
5686<h5>Overview:</h5>
5687
5688<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5689The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5690values with an even number of bytes (positive multiple of 16 bits). These are
5691useful for performing operations on data that is not in the target's native
5692byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5693</p>
5694
5695<h5>Semantics:</h5>
5696
5697<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5698The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5699and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5700intrinsic returns an i32 value that has the four bytes of the input i32
5701swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5702i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5703<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5704additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5705</p>
5706
5707</div>
5708
5709<!-- _______________________________________________________________________ -->
5710<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5711 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5712</div>
5713
5714<div class="doc_text">
5715
5716<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5717<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5718width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5719<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5720 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5721 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5722 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5723 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5724 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5725</pre>
5726
5727<h5>Overview:</h5>
5728
5729<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5730The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5731value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5732</p>
5733
5734<h5>Arguments:</h5>
5735
5736<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5737The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5738integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5739</p>
5740
5741<h5>Semantics:</h5>
5742
5743<p>
5744The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5745</p>
5746</div>
5747
5748<!-- _______________________________________________________________________ -->
5749<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5750 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5751</div>
5752
5753<div class="doc_text">
5754
5755<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5756<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5757integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5758<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5759 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5760 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5761 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5762 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5763 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5764</pre>
5765
5766<h5>Overview:</h5>
5767
5768<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5769The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5770leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5771</p>
5772
5773<h5>Arguments:</h5>
5774
5775<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5776The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5777integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5778</p>
5779
5780<h5>Semantics:</h5>
5781
5782<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5783The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5784in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5785of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5786</p>
5787</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5788
5789
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5790
5791<!-- _______________________________________________________________________ -->
5792<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5793 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5794</div>
5795
5796<div class="doc_text">
5797
5798<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5799<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5800integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5801<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5802 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5803 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5804 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5805 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5806 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5807</pre>
5808
5809<h5>Overview:</h5>
5810
5811<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5812The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5813trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5814</p>
5815
5816<h5>Arguments:</h5>
5817
5818<p>
5819The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5820integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5821</p>
5822
5823<h5>Semantics:</h5>
5824
5825<p>
5826The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5827in a variable. If the src == 0 then the result is the size in bits of the type
5828of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5829</p>
5830</div>
5831
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5832<!-- _______________________________________________________________________ -->
5833<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5834 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5835</div>
5836
5837<div class="doc_text">
5838
5839<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5840<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5841on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5842<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5843 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5844 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5845</pre>
5846
5847<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5848<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5849range of bits from an integer value and returns them in the same bit width as
5850the original value.</p>
5851
5852<h5>Arguments:</h5>
5853<p>The first argument, <tt>%val</tt> and the result may be integer types of
5854any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5855arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5856
5857<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5858<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5859of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5860<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5861operates in forward mode.</p>
5862<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5863right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5864only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5865<ol>
5866 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5867 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5868 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5869 to determine the number of bits to retain.</li>
5870 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5871 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5872</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5873<p>In reverse mode, a similar computation is made except that the bits are
5874returned in the reverse order. So, for example, if <tt>X</tt> has the value
5875<tt>i16 0x0ACF (101011001111)</tt> and we apply
5876<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5877<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5878</div>
5879
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5880<div class="doc_subsubsection">
5881 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5882</div>
5883
5884<div class="doc_text">
5885
5886<h5>Syntax:</h5>
5887<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5888on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5889<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5890 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5891 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5892</pre>
5893
5894<h5>Overview:</h5>
5895<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5896of bits in an integer value with another integer value. It returns the integer
5897with the replaced bits.</p>
5898
5899<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5900<p>The first argument, <tt>%val</tt>, and the result may be integer types of
5901any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5902whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5903integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5904type since they specify only a bit index.</p>
5905
5906<h5>Semantics:</h5>
5907<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5908of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5909<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5910operates in forward mode.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5911
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5912<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5913truncating it down to the size of the replacement area or zero extending it
5914up to that size.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5915
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5916<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5917are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5918in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5919to the <tt>%hi</tt>th bit.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5920
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5921<p>In reverse mode, a similar computation is made except that the bits are
5922reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5923<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5924
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5925<h5>Examples:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5926
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5927<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5928 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5929 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5930 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5931 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5932 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5933</pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5934
5935</div>
5936
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5937<!-- ======================================================================= -->
5938<div class="doc_subsection">
5939 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5940</div>
5941
5942<div class="doc_text">
5943<p>
5944LLVM provides intrinsics for some arithmetic with overflow operations.
5945</p>
5946
5947</div>
5948
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5949<!-- _______________________________________________________________________ -->
5950<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5951 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5952</div>
5953
5954<div class="doc_text">
5955
5956<h5>Syntax:</h5>
5957
5958<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5959on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5960
5961<pre>
5962 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5963 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5964 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5965</pre>
5966
5967<h5>Overview:</h5>
5968
5969<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5970a signed addition of the two arguments, and indicate whether an overflow
5971occurred during the signed summation.</p>
5972
5973<h5>Arguments:</h5>
5974
5975<p>The arguments (%a and %b) and the first element of the result structure may
5976be of integer types of any bit width, but they must have the same bit width. The
5977second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
5978and <tt>%b</tt> are the two values that will undergo signed addition.</p>
5979
5980<h5>Semantics:</h5>
5981
5982<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5983a signed addition of the two variables. They return a structure &mdash; the
5984first element of which is the signed summation, and the second element of which
5985is a bit specifying if the signed summation resulted in an overflow.</p>
5986
5987<h5>Examples:</h5>
5988<pre>
5989 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5990 %sum = extractvalue {i32, i1} %res, 0
5991 %obit = extractvalue {i32, i1} %res, 1
5992 br i1 %obit, label %overflow, label %normal
5993</pre>
5994
5995</div>
5996
5997<!-- _______________________________________________________________________ -->
5998<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5999 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6000</div>
6001
6002<div class="doc_text">
6003
6004<h5>Syntax:</h5>
6005
6006<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6007on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6008
6009<pre>
6010 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6011 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6012 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6013</pre>
6014
6015<h5>Overview:</h5>
6016
6017<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6018an unsigned addition of the two arguments, and indicate whether a carry occurred
6019during the unsigned summation.</p>
6020
6021<h5>Arguments:</h5>
6022
6023<p>The arguments (%a and %b) and the first element of the result structure may
6024be of integer types of any bit width, but they must have the same bit width. The
6025second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6026and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
6027
6028<h5>Semantics:</h5>
6029
6030<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6031an unsigned addition of the two arguments. They return a structure &mdash; the
6032first element of which is the sum, and the second element of which is a bit
6033specifying if the unsigned summation resulted in a carry.</p>
6034
6035<h5>Examples:</h5>
6036<pre>
6037 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6038 %sum = extractvalue {i32, i1} %res, 0
6039 %obit = extractvalue {i32, i1} %res, 1
6040 br i1 %obit, label %carry, label %normal
6041</pre>
6042
6043</div>
6044
6045<!-- _______________________________________________________________________ -->
6046<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6047 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6048</div>
6049
6050<div class="doc_text">
6051
6052<h5>Syntax:</h5>
6053
6054<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6055on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6056
6057<pre>
6058 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6059 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6060 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6061</pre>
6062
6063<h5>Overview:</h5>
6064
6065<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6066a signed subtraction of the two arguments, and indicate whether an overflow
6067occurred during the signed subtraction.</p>
6068
6069<h5>Arguments:</h5>
6070
6071<p>The arguments (%a and %b) and the first element of the result structure may
6072be of integer types of any bit width, but they must have the same bit width. The
6073second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6074and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
6075
6076<h5>Semantics:</h5>
6077
6078<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6079a signed subtraction of the two arguments. They return a structure &mdash; the
6080first element of which is the subtraction, and the second element of which is a bit
6081specifying if the signed subtraction resulted in an overflow.</p>
6082
6083<h5>Examples:</h5>
6084<pre>
6085 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6086 %sum = extractvalue {i32, i1} %res, 0
6087 %obit = extractvalue {i32, i1} %res, 1
6088 br i1 %obit, label %overflow, label %normal
6089</pre>
6090
6091</div>
6092
6093<!-- _______________________________________________________________________ -->
6094<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6095 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6096</div>
6097
6098<div class="doc_text">
6099
6100<h5>Syntax:</h5>
6101
6102<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6103on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6104
6105<pre>
6106 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6107 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6108 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6109</pre>
6110
6111<h5>Overview:</h5>
6112
6113<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6114an unsigned subtraction of the two arguments, and indicate whether an overflow
6115occurred during the unsigned subtraction.</p>
6116
6117<h5>Arguments:</h5>
6118
6119<p>The arguments (%a and %b) and the first element of the result structure may
6120be of integer types of any bit width, but they must have the same bit width. The
6121second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6122and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
6123
6124<h5>Semantics:</h5>
6125
6126<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6127an unsigned subtraction of the two arguments. They return a structure &mdash; the
6128first element of which is the subtraction, and the second element of which is a bit
6129specifying if the unsigned subtraction resulted in an overflow.</p>
6130
6131<h5>Examples:</h5>
6132<pre>
6133 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6134 %sum = extractvalue {i32, i1} %res, 0
6135 %obit = extractvalue {i32, i1} %res, 1
6136 br i1 %obit, label %overflow, label %normal
6137</pre>
6138
6139</div>
6140
6141<!-- _______________________________________________________________________ -->
6142<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6143 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6144</div>
6145
6146<div class="doc_text">
6147
6148<h5>Syntax:</h5>
6149
6150<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6151on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6152
6153<pre>
6154 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6155 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6156 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6157</pre>
6158
6159<h5>Overview:</h5>
6160
6161<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6162a signed multiplication of the two arguments, and indicate whether an overflow
6163occurred during the signed multiplication.</p>
6164
6165<h5>Arguments:</h5>
6166
6167<p>The arguments (%a and %b) and the first element of the result structure may
6168be of integer types of any bit width, but they must have the same bit width. The
6169second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6170and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
6171
6172<h5>Semantics:</h5>
6173
6174<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6175a signed multiplication of the two arguments. They return a structure &mdash;
6176the first element of which is the multiplication, and the second element of
6177which is a bit specifying if the signed multiplication resulted in an
6178overflow.</p>
6179
6180<h5>Examples:</h5>
6181<pre>
6182 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6183 %sum = extractvalue {i32, i1} %res, 0
6184 %obit = extractvalue {i32, i1} %res, 1
6185 br i1 %obit, label %overflow, label %normal
6186</pre>
6187
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6188</div>
6189
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6190<!-- _______________________________________________________________________ -->
6191<div class="doc_subsubsection">
6192 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6193</div>
6194
6195<div class="doc_text">
6196
6197<h5>Syntax:</h5>
6198
6199<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
6200on any integer bit width.</p>
6201
6202<pre>
6203 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6204 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6205 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6206</pre>
6207
6208<h5>Overview:</h5>
6209
6210<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
6211actively being fixed, but it should not currently be used!</i></p>
6212
6213<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6214a unsigned multiplication of the two arguments, and indicate whether an overflow
6215occurred during the unsigned multiplication.</p>
6216
6217<h5>Arguments:</h5>
6218
6219<p>The arguments (%a and %b) and the first element of the result structure may
6220be of integer types of any bit width, but they must have the same bit width. The
6221second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6222and <tt>%b</tt> are the two values that will undergo unsigned
6223multiplication.</p>
6224
6225<h5>Semantics:</h5>
6226
6227<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6228an unsigned multiplication of the two arguments. They return a structure &mdash;
6229the first element of which is the multiplication, and the second element of
6230which is a bit specifying if the unsigned multiplication resulted in an
6231overflow.</p>
6232
6233<h5>Examples:</h5>
6234<pre>
6235 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6236 %sum = extractvalue {i32, i1} %res, 0
6237 %obit = extractvalue {i32, i1} %res, 1
6238 br i1 %obit, label %overflow, label %normal
6239</pre>
6240
6241</div>
6242
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6243<!-- ======================================================================= -->
6244<div class="doc_subsection">
6245 <a name="int_debugger">Debugger Intrinsics</a>
6246</div>
6247
6248<div class="doc_text">
6249<p>
6250The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
6251are described in the <a
6252href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
6253Debugging</a> document.
6254</p>
6255</div>
6256
6257
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6258<!-- ======================================================================= -->
6259<div class="doc_subsection">
6260 <a name="int_eh">Exception Handling Intrinsics</a>
6261</div>
6262
6263<div class="doc_text">
6264<p> The LLVM exception handling intrinsics (which all start with
6265<tt>llvm.eh.</tt> prefix), are described in the <a
6266href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6267Handling</a> document. </p>
6268</div>
6269
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6270<!-- ======================================================================= -->
6271<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6272 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6273</div>
6274
6275<div class="doc_text">
6276<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6277 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6278 the <tt>nest</tt> attribute, from a function. The result is a callable
6279 function pointer lacking the nest parameter - the caller does not need
6280 to provide a value for it. Instead, the value to use is stored in
6281 advance in a "trampoline", a block of memory usually allocated
6282 on the stack, which also contains code to splice the nest value into the
6283 argument list. This is used to implement the GCC nested function address
6284 extension.
6285</p>
6286<p>
6287 For example, if the function is
6288 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]6289 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6290<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6291 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6292 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6293 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6294 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6295</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]6296 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6297 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6298</div>
6299
6300<!-- _______________________________________________________________________ -->
6301<div class="doc_subsubsection">
6302 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6303</div>
6304<div class="doc_text">
6305<h5>Syntax:</h5>
6306<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6307declare 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]6308</pre>
6309<h5>Overview:</h5>
6310<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6311 This fills the memory pointed to by <tt>tramp</tt> with code
6312 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6313</p>
6314<h5>Arguments:</h5>
6315<p>
6316 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6317 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
6318 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]6319 intrinsic. Note that the size and the alignment are target-specific - LLVM
6320 currently provides no portable way of determining them, so a front-end that
6321 generates this intrinsic needs to have some target-specific knowledge.
6322 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6323</p>
6324<h5>Semantics:</h5>
6325<p>
6326 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6327 dependent code, turning it into a function. A pointer to this function is
6328 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6329 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6330 before being called. The new function's signature is the same as that of
6331 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
6332 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
6333 of pointer type. Calling the new function is equivalent to calling
6334 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
6335 missing <tt>nest</tt> argument. If, after calling
6336 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
6337 modified, then the effect of any later call to the returned function pointer is
6338 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6339</p>
6340</div>
6341
6342<!-- ======================================================================= -->
6343<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6344 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6345</div>
6346
6347<div class="doc_text">
6348<p>
6349 These intrinsic functions expand the "universal IR" of LLVM to represent
6350 hardware constructs for atomic operations and memory synchronization. This
6351 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6352 is aimed at a low enough level to allow any programming models or APIs
6353 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6354 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6355 hardware behavior. Just as hardware provides a "universal IR" for source
6356 languages, it also provides a starting point for developing a "universal"
6357 atomic operation and synchronization IR.
6358</p>
6359<p>
6360 These do <em>not</em> form an API such as high-level threading libraries,
6361 software transaction memory systems, atomic primitives, and intrinsic
6362 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6363 application libraries. The hardware interface provided by LLVM should allow
6364 a clean implementation of all of these APIs and parallel programming models.
6365 No one model or paradigm should be selected above others unless the hardware
6366 itself ubiquitously does so.
6367
6368</p>
6369</div>
6370
6371<!-- _______________________________________________________________________ -->
6372<div class="doc_subsubsection">
6373 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6374</div>
6375<div class="doc_text">
6376<h5>Syntax:</h5>
6377<pre>
6378declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6379i1 &lt;device&gt; )
6380
6381</pre>
6382<h5>Overview:</h5>
6383<p>
6384 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6385 specific pairs of memory access types.
6386</p>
6387<h5>Arguments:</h5>
6388<p>
6389 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6390 The first four arguments enables a specific barrier as listed below. The fith
6391 argument specifies that the barrier applies to io or device or uncached memory.
6392
6393</p>
6394 <ul>
6395 <li><tt>ll</tt>: load-load barrier</li>
6396 <li><tt>ls</tt>: load-store barrier</li>
6397 <li><tt>sl</tt>: store-load barrier</li>
6398 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6399 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6400 </ul>
6401<h5>Semantics:</h5>
6402<p>
6403 This intrinsic causes the system to enforce some ordering constraints upon
6404 the loads and stores of the program. This barrier does not indicate
6405 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6406 which they occur. For any of the specified pairs of load and store operations
6407 (f.ex. load-load, or store-load), all of the first operations preceding the
6408 barrier will complete before any of the second operations succeeding the
6409 barrier begin. Specifically the semantics for each pairing is as follows:
6410</p>
6411 <ul>
6412 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6413 after the barrier begins.</li>
6414
6415 <li><tt>ls</tt>: All loads before the barrier must complete before any
6416 store after the barrier begins.</li>
6417 <li><tt>ss</tt>: All stores before the barrier must complete before any
6418 store after the barrier begins.</li>
6419 <li><tt>sl</tt>: All stores before the barrier must complete before any
6420 load after the barrier begins.</li>
6421 </ul>
6422<p>
6423 These semantics are applied with a logical "and" behavior when more than one
6424 is enabled in a single memory barrier intrinsic.
6425</p>
6426<p>
6427 Backends may implement stronger barriers than those requested when they do not
6428 support as fine grained a barrier as requested. Some architectures do not
6429 need all types of barriers and on such architectures, these become noops.
6430</p>
6431<h5>Example:</h5>
6432<pre>
6433%ptr = malloc i32
6434 store i32 4, %ptr
6435
6436%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6437 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6438 <i>; guarantee the above finishes</i>
6439 store i32 8, %ptr <i>; before this begins</i>
6440</pre>
6441</div>
6442
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6443<!-- _______________________________________________________________________ -->
6444<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6445 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6446</div>
6447<div class="doc_text">
6448<h5>Syntax:</h5>
6449<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6450 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6451 any integer bit width and for different address spaces. Not all targets
6452 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6453
6454<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6455declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6456declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6457declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6458declare 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]6459
6460</pre>
6461<h5>Overview:</h5>
6462<p>
6463 This loads a value in memory and compares it to a given value. If they are
6464 equal, it stores a new value into the memory.
6465</p>
6466<h5>Arguments:</h5>
6467<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6468 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6469 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6470 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6471 this integer type. While any bit width integer may be used, targets may only
6472 lower representations they support in hardware.
6473
6474</p>
6475<h5>Semantics:</h5>
6476<p>
6477 This entire intrinsic must be executed atomically. It first loads the value
6478 in memory pointed to by <tt>ptr</tt> and compares it with the value
6479 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6480 loaded value is yielded in all cases. This provides the equivalent of an
6481 atomic compare-and-swap operation within the SSA framework.
6482</p>
6483<h5>Examples:</h5>
6484
6485<pre>
6486%ptr = malloc i32
6487 store i32 4, %ptr
6488
6489%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6490%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6491 <i>; yields {i32}:result1 = 4</i>
6492%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6493%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6494
6495%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6496%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6497 <i>; yields {i32}:result2 = 8</i>
6498%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6499
6500%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6501</pre>
6502</div>
6503
6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
6506 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6507</div>
6508<div class="doc_text">
6509<h5>Syntax:</h5>
6510
6511<p>
6512 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6513 integer bit width. Not all targets support all bit widths however.</p>
6514<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6515declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6516declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6517declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6518declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6519
6520</pre>
6521<h5>Overview:</h5>
6522<p>
6523 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6524 the value from memory. It then stores the value in <tt>val</tt> in the memory
6525 at <tt>ptr</tt>.
6526</p>
6527<h5>Arguments:</h5>
6528
6529<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6530 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6531 <tt>val</tt> argument and the result must be integers of the same bit width.
6532 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6533 integer type. The targets may only lower integer representations they
6534 support.
6535</p>
6536<h5>Semantics:</h5>
6537<p>
6538 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6539 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6540 equivalent of an atomic swap operation within the SSA framework.
6541
6542</p>
6543<h5>Examples:</h5>
6544<pre>
6545%ptr = malloc i32
6546 store i32 4, %ptr
6547
6548%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6549%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6550 <i>; yields {i32}:result1 = 4</i>
6551%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6552%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6553
6554%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6555%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6556 <i>; yields {i32}:result2 = 8</i>
6557
6558%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6559%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6560</pre>
6561</div>
6562
6563<!-- _______________________________________________________________________ -->
6564<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6565 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6566
6567</div>
6568<div class="doc_text">
6569<h5>Syntax:</h5>
6570<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6571 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6572 integer bit width. Not all targets support all bit widths however.</p>
6573<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6574declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6575declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6576declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6577declare 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]6578
6579</pre>
6580<h5>Overview:</h5>
6581<p>
6582 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6583 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6584</p>
6585<h5>Arguments:</h5>
6586<p>
6587
6588 The intrinsic takes two arguments, the first a pointer to an integer value
6589 and the second an integer value. The result is also an integer value. These
6590 integer types can have any bit width, but they must all have the same bit
6591 width. The targets may only lower integer representations they support.
6592</p>
6593<h5>Semantics:</h5>
6594<p>
6595 This intrinsic does a series of operations atomically. It first loads the
6596 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6597 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6598</p>
6599
6600<h5>Examples:</h5>
6601<pre>
6602%ptr = malloc i32
6603 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6604%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6605 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6606%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6607 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6608%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6609 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6610%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6611</pre>
6612</div>
6613
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6614<!-- _______________________________________________________________________ -->
6615<div class="doc_subsubsection">
6616 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6617
6618</div>
6619<div class="doc_text">
6620<h5>Syntax:</h5>
6621<p>
6622 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6623 any integer bit width and for different address spaces. Not all targets
6624 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6625<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6626declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6627declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6628declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6629declare 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]6630
6631</pre>
6632<h5>Overview:</h5>
6633<p>
6634 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6635 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6636</p>
6637<h5>Arguments:</h5>
6638<p>
6639
6640 The intrinsic takes two arguments, the first a pointer to an integer value
6641 and the second an integer value. The result is also an integer value. These
6642 integer types can have any bit width, but they must all have the same bit
6643 width. The targets may only lower integer representations they support.
6644</p>
6645<h5>Semantics:</h5>
6646<p>
6647 This intrinsic does a series of operations atomically. It first loads the
6648 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6649 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6650</p>
6651
6652<h5>Examples:</h5>
6653<pre>
6654%ptr = malloc i32
6655 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6656%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6657 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6658%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6659 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6660%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6661 <i>; yields {i32}:result3 = 2</i>
6662%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6663</pre>
6664</div>
6665
6666<!-- _______________________________________________________________________ -->
6667<div class="doc_subsubsection">
6668 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6669 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6670 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6671 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6672
6673</div>
6674<div class="doc_text">
6675<h5>Syntax:</h5>
6676<p>
6677 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6678 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6679 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6680 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6681<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6682declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6683declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6684declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6685declare 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]6686
6687</pre>
6688
6689<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6690declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6691declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6692declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6693declare 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]6694
6695</pre>
6696
6697<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6698declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6699declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6700declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6701declare 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]6702
6703</pre>
6704
6705<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6706declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6707declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6708declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6709declare 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]6710
6711</pre>
6712<h5>Overview:</h5>
6713<p>
6714 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6715 the value stored in memory at <tt>ptr</tt>. It yields the original value
6716 at <tt>ptr</tt>.
6717</p>
6718<h5>Arguments:</h5>
6719<p>
6720
6721 These intrinsics take two arguments, the first a pointer to an integer value
6722 and the second an integer value. The result is also an integer value. These
6723 integer types can have any bit width, but they must all have the same bit
6724 width. The targets may only lower integer representations they support.
6725</p>
6726<h5>Semantics:</h5>
6727<p>
6728 These intrinsics does a series of operations atomically. They first load the
6729 value stored at <tt>ptr</tt>. They then do the bitwise operation
6730 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6731 value stored at <tt>ptr</tt>.
6732</p>
6733
6734<h5>Examples:</h5>
6735<pre>
6736%ptr = malloc i32
6737 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6738%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6739 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6740%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6741 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6742%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6743 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6744%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6745 <i>; yields {i32}:result3 = FF</i>
6746%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6747</pre>
6748</div>
6749
6750
6751<!-- _______________________________________________________________________ -->
6752<div class="doc_subsubsection">
6753 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6754 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6755 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6756 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6757
6758</div>
6759<div class="doc_text">
6760<h5>Syntax:</h5>
6761<p>
6762 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6763 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6764 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6765 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6766 support all bit widths however.</p>
6767<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6768declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6769declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6770declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6771declare 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]6772
6773</pre>
6774
6775<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6776declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6777declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6778declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6779declare 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]6780
6781</pre>
6782
6783<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6784declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6785declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6786declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6787declare 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]6788
6789</pre>
6790
6791<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6792declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6793declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6794declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6795declare 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]6796
6797</pre>
6798<h5>Overview:</h5>
6799<p>
6800 These intrinsics takes the signed or unsigned minimum or maximum of
6801 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6802 original value at <tt>ptr</tt>.
6803</p>
6804<h5>Arguments:</h5>
6805<p>
6806
6807 These intrinsics take two arguments, the first a pointer to an integer value
6808 and the second an integer value. The result is also an integer value. These
6809 integer types can have any bit width, but they must all have the same bit
6810 width. The targets may only lower integer representations they support.
6811</p>
6812<h5>Semantics:</h5>
6813<p>
6814 These intrinsics does a series of operations atomically. They first load the
6815 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6816 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6817 the original value stored at <tt>ptr</tt>.
6818</p>
6819
6820<h5>Examples:</h5>
6821<pre>
6822%ptr = malloc i32
6823 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6824%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6825 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6826%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6827 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6828%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6829 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6830%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6831 <i>; yields {i32}:result3 = 8</i>
6832%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6833</pre>
6834</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6835
6836<!-- ======================================================================= -->
6837<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6838 <a name="int_general">General Intrinsics</a>
6839</div>
6840
6841<div class="doc_text">
6842<p> This class of intrinsics is designed to be generic and has
6843no specific purpose. </p>
6844</div>
6845
6846<!-- _______________________________________________________________________ -->
6847<div class="doc_subsubsection">
6848 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6849</div>
6850
6851<div class="doc_text">
6852
6853<h5>Syntax:</h5>
6854<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6855 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]6856</pre>
6857
6858<h5>Overview:</h5>
6859
6860<p>
6861The '<tt>llvm.var.annotation</tt>' intrinsic
6862</p>
6863
6864<h5>Arguments:</h5>
6865
6866<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6867The first argument is a pointer to a value, the second is a pointer to a
6868global string, the third is a pointer to a global string which is the source
6869file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6870</p>
6871
6872<h5>Semantics:</h5>
6873
6874<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6875This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6876This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6877annotations. These have no other defined use, they are ignored by code
6878generation and optimization.
6879</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6880</div>
6881
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6882<!-- _______________________________________________________________________ -->
6883<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6884 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6885</div>
6886
6887<div class="doc_text">
6888
6889<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6890<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6891any integer bit width.
6892</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6893<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6894 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6895 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6896 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6897 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6898 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]6899</pre>
6900
6901<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6902
6903<p>
6904The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6905</p>
6906
6907<h5>Arguments:</h5>
6908
6909<p>
6910The first argument is an integer value (result of some expression),
6911the second is a pointer to a global string, the third is a pointer to a global
6912string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6913It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6914</p>
6915
6916<h5>Semantics:</h5>
6917
6918<p>
6919This intrinsic allows annotations to be put on arbitrary expressions
6920with arbitrary strings. This can be useful for special purpose optimizations
6921that want to look for these annotations. These have no other defined use, they
6922are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6923</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6924</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6925
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6926<!-- _______________________________________________________________________ -->
6927<div class="doc_subsubsection">
6928 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6929</div>
6930
6931<div class="doc_text">
6932
6933<h5>Syntax:</h5>
6934<pre>
6935 declare void @llvm.trap()
6936</pre>
6937
6938<h5>Overview:</h5>
6939
6940<p>
6941The '<tt>llvm.trap</tt>' intrinsic
6942</p>
6943
6944<h5>Arguments:</h5>
6945
6946<p>
6947None
6948</p>
6949
6950<h5>Semantics:</h5>
6951
6952<p>
6953This intrinsics is lowered to the target dependent trap instruction. If the
6954target does not have a trap instruction, this intrinsic will be lowered to the
6955call of the abort() function.
6956</p>
6957</div>
6958
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6959<!-- _______________________________________________________________________ -->
6960<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6961 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6962</div>
6963<div class="doc_text">
6964<h5>Syntax:</h5>
6965<pre>
6966declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6967
6968</pre>
6969<h5>Overview:</h5>
6970<p>
6971 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6972 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6973 it is placed on the stack before local variables.
6974</p>
6975<h5>Arguments:</h5>
6976<p>
6977 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6978 first argument is the value loaded from the stack guard
6979 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6980 has enough space to hold the value of the guard.
6981</p>
6982<h5>Semantics:</h5>
6983<p>
6984 This intrinsic causes the prologue/epilogue inserter to force the position of
6985 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6986 stack. This is to ensure that if a local variable on the stack is overwritten,
6987 it will destroy the value of the guard. When the function exits, the guard on
6988 the stack is checked against the original guard. If they're different, then
6989 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6990</p>
6991</div>
6992
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6993<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6994<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6995<address>
6996 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6997 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6998 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6999 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]7000
7001 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]7002 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7003 Last modified: $Date$
7004</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]7005
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]7006</body>
7007</html>