Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / 6de96a1b5d77b13719760d0143ef48e8670b6e20 / . / llvm / docs / LangRef.html
blob: 5eef22532621e6f298e0f25f9b3307c5f32b23f9 [file] [log] [blame]
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3<html>
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>
58 </ol>
59 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]60 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]61 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]62 <li><a href="#simpleconstants">Simple Constants</a></li>
63 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
64 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
65 <li><a href="#undefvalues">Undefined Values</a></li>
66 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]67 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]68 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]69 <li><a href="#othervalues">Other Values</a>
70 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]71 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]72 </ol>
73 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]74 <li><a href="#instref">Instruction Reference</a>
75 <ol>
76 <li><a href="#terminators">Terminator Instructions</a>
77 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]78 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
79 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]80 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
81 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]82 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]83 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]86 <li><a href="#binaryops">Binary Operations</a>
87 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]88 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
89 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
90 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]91 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
92 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
93 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]94 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
95 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
96 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]97 </ol>
98 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]99 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
100 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]101 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
102 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
103 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]104 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]105 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]106 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]109 <li><a href="#vectorops">Vector Operations</a>
110 <ol>
111 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
112 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
113 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]114 </ol>
115 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]116 <li><a href="#aggregateops">Aggregate Operations</a>
117 <ol>
118 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
119 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
120 </ol>
121 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]122 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]123 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
125 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
126 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]127 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
128 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
129 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]130 </ol>
131 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]132 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]133 <ol>
134 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
135 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]139 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
140 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
141 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
142 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]143 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
144 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]145 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]146 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]147 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]148 <li><a href="#otherops">Other Operations</a>
149 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]150 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
151 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]152 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
153 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]154 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]155 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]156 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]157 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]158 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]159 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]160 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]161 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]162 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]163 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]164 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
165 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]166 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]169 </ol>
170 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]171 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
172 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]173 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]176 </ol>
177 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]178 <li><a href="#int_codegen">Code Generator Intrinsics</a>
179 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]180 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
183 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
184 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
185 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
186 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]187 </ol>
188 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]189 <li><a href="#int_libc">Standard C Library Intrinsics</a>
190 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]191 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]196 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]199 </ol>
200 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]201 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]202 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]203 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]204 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]207 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
208 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]211 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]212 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]213 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]214 <ol>
215 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]216 </ol>
217 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]218 <li><a href="#int_atomics">Atomic intrinsics</a>
219 <ol>
220 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
221 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
222 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
223 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
224 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
225 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
226 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
227 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
228 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
229 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
230 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
231 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
232 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
233 </ol>
234 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]235 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]236 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]237 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]238 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]239 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]240 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]241 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]242 '<tt>llvm.trap</tt>' Intrinsic</a></li>
243 <li><a href="#int_stackprotector">
244 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]245 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]246 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]247 </ol>
248 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]249</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]250
251<div class="doc_author">
252 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
253 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]254</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]255
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]256<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]257<div class="doc_section"> <a name="abstract">Abstract </a></div>
258<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]259
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]260<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]261<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]262LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]263type safety, low-level operations, flexibility, and the capability of
264representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]265representation used throughout all phases of the LLVM compilation
266strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]267</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]268
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]269<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]270<div class="doc_section"> <a name="introduction">Introduction</a> </div>
271<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]272
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]273<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]275<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]276different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]277representation (suitable for fast loading by a Just-In-Time compiler),
278and as a human readable assembly language representation. This allows
279LLVM to provide a powerful intermediate representation for efficient
280compiler transformations and analysis, while providing a natural means
281to debug and visualize the transformations. The three different forms
282of LLVM are all equivalent. This document describes the human readable
283representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]284
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]285<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]286while being expressive, typed, and extensible at the same time. It
287aims to be a "universal IR" of sorts, by being at a low enough level
288that high-level ideas may be cleanly mapped to it (similar to how
289microprocessors are "universal IR's", allowing many source languages to
290be mapped to them). By providing type information, LLVM can be used as
291the target of optimizations: for example, through pointer analysis, it
292can be proven that a C automatic variable is never accessed outside of
293the current function... allowing it to be promoted to a simple SSA
294value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]296</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]297
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]298<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]299<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]302
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]303<p>It is important to note that this document describes 'well formed'
304LLVM assembly language. There is a difference between what the parser
305accepts and what is considered 'well formed'. For example, the
306following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]307
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]308<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]309<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]310%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]311</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]312</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]313
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]314<p>...because the definition of <tt>%x</tt> does not dominate all of
315its uses. The LLVM infrastructure provides a verification pass that may
316be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]317automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]318the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]319by the verifier pass indicate bugs in transformation passes or input to
320the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]321</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]322
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]323<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]326<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]329<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]330
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]331 <p>LLVM identifiers come in two basic types: global and local. Global
332 identifiers (functions, global variables) begin with the @ character. Local
333 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]334 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]335
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]336<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]337 <li>Named values are represented as a string of characters with their prefix.
338 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
339 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]340 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame]341 with quotes. Special characters may be escaped using "\xx" where xx is the
342 ASCII code for the character in hexadecimal. In this way, any character can
343 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]344
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]345 <li>Unnamed values are represented as an unsigned numeric value with their
346 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]347
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]348 <li>Constants, which are described in a <a href="#constants">section about
349 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]350</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]351
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]352<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]353don't need to worry about name clashes with reserved words, and the set of
354reserved words may be expanded in the future without penalty. Additionally,
355unnamed identifiers allow a compiler to quickly come up with a temporary
356variable without having to avoid symbol table conflicts.</p>
357
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]358<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]359languages. There are keywords for different opcodes
360('<tt><a href="#i_add">add</a></tt>',
361 '<tt><a href="#i_bitcast">bitcast</a></tt>',
362 '<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]363href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]364and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]365none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]366
367<p>Here is an example of LLVM code to multiply the integer variable
368'<tt>%X</tt>' by 8:</p>
369
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]370<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]371
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]372<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]373<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]374%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]375</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]376</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]377
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]378<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]379
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]380<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]381<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]382%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]383</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]384</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]385
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]386<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]387
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]388<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]389<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]390<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
391<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
392%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]393</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]394</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]395
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]396<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
397important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]399<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]400
401 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
402 line.</li>
403
404 <li>Unnamed temporaries are created when the result of a computation is not
405 assigned to a named value.</li>
406
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]407 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]408
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]409</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]410
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]411<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]412demonstrating instructions, we will follow an instruction with a comment that
413defines the type and name of value produced. Comments are shown in italic
414text.</p>
415
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]416</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]417
418<!-- *********************************************************************** -->
419<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
420<!-- *********************************************************************** -->
421
422<!-- ======================================================================= -->
423<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
424</div>
425
426<div class="doc_text">
427
428<p>LLVM programs are composed of "Module"s, each of which is a
429translation unit of the input programs. Each module consists of
430functions, global variables, and symbol table entries. Modules may be
431combined together with the LLVM linker, which merges function (and
432global variable) definitions, resolves forward declarations, and merges
433symbol table entries. Here is an example of the "hello world" module:</p>
434
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]435<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]436<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]437<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
438 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]439
440<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]441<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]442
443<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]444define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]445 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]446 %cast210 = <a
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]447 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]448
449 <i>; Call puts function to write out the string to stdout...</i>
450 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]451 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]452 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]453 href="#i_ret">ret</a> i32 0<br>}<br>
454</pre>
455</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]456
457<p>This example is made up of a <a href="#globalvars">global variable</a>
458named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
459function, and a <a href="#functionstructure">function definition</a>
460for "<tt>main</tt>".</p>
461
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]462<p>In general, a module is made up of a list of global values,
463where both functions and global variables are global values. Global values are
464represented by a pointer to a memory location (in this case, a pointer to an
465array of char, and a pointer to a function), and have one of the following <a
466href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]467
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]468</div>
469
470<!-- ======================================================================= -->
471<div class="doc_subsection">
472 <a name="linkage">Linkage Types</a>
473</div>
474
475<div class="doc_text">
476
477<p>
478All Global Variables and Functions have one of the following types of linkage:
479</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]482
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame^]483 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
484
485 <dd>Global values with private linkage are only directly accessible by
486 objects in the current module. In particular, linking code into a module with
487 an private global value may cause the private to be renamed as necessary to
488 avoid collisions. Because the symbol is private to the module, all
489 references can be updated. This doesn't show up in any symbol table in the
490 object file.
491 </dd>
492
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]493 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]494
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame^]495 <dd> Similar to private, but the value show as a local symbol (STB_LOCAL in
496 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]497 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]498 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]499
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]500 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]501
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]502 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
503 the same name when linkage occurs. This is typically used to implement
504 inline functions, templates, or other code which must be generated in each
505 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
506 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]508
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]509 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
510
511 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
512 linkage, except that unreferenced <tt>common</tt> globals may not be
513 discarded. This is used for globals that may be emitted in multiple
514 translation units, but that are not guaranteed to be emitted into every
515 translation unit that uses them. One example of this is tentative
516 definitions in C, such as "<tt>int X;</tt>" at global scope.
517 </dd>
518
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]519 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]520
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]521 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
522 that some targets may choose to emit different assembly sequences for them
523 for target-dependent reasons. This is used for globals that are declared
524 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]525 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]526
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]527 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]528
529 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
530 pointer to array type. When two global variables with appending linkage are
531 linked together, the two global arrays are appended together. This is the
532 LLVM, typesafe, equivalent of having the system linker append together
533 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]534 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]535
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]536 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]537 <dd>The semantics of this linkage follow the ELF object file model: the
538 symbol is weak until linked, if not linked, the symbol becomes null instead
539 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]540 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]541
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]542 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]543
544 <dd>If none of the above identifiers are used, the global is externally
545 visible, meaning that it participates in linkage and can be used to resolve
546 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]547 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]548</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]549
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]550 <p>
551 The next two types of linkage are targeted for Microsoft Windows platform
552 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]553 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]554 </p>
555
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]556 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]557 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
558
559 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
560 or variable via a global pointer to a pointer that is set up by the DLL
561 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame]562 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]563 </dd>
564
565 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
566
567 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
568 pointer to a pointer in a DLL, so that it can be referenced with the
569 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame]570 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]571 name.
572 </dd>
573
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]574</dl>
575
Dan Gohman8ef44982008-11-24 17:18:39 +0000[diff] [blame]576<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]577variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
578variable and was linked with this one, one of the two would be renamed,
579preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
580external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]581outside of the current module.</p>
582<p>It is illegal for a function <i>declaration</i>
583to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]584or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]585<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]586linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]587</div>
588
589<!-- ======================================================================= -->
590<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]591 <a name="callingconv">Calling Conventions</a>
592</div>
593
594<div class="doc_text">
595
596<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
597and <a href="#i_invoke">invokes</a> can all have an optional calling convention
598specified for the call. The calling convention of any pair of dynamic
599caller/callee must match, or the behavior of the program is undefined. The
600following calling conventions are supported by LLVM, and more may be added in
601the future:</p>
602
603<dl>
604 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
605
606 <dd>This calling convention (the default if no other calling convention is
607 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]608 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]609 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]610 </dd>
611
612 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
613
614 <dd>This calling convention attempts to make calls as fast as possible
615 (e.g. by passing things in registers). This calling convention allows the
616 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]617 without having to conform to an externally specified ABI (Application Binary
618 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]619 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
620 supported. This calling convention does not support varargs and requires the
621 prototype of all callees to exactly match the prototype of the function
622 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]623 </dd>
624
625 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
626
627 <dd>This calling convention attempts to make code in the caller as efficient
628 as possible under the assumption that the call is not commonly executed. As
629 such, these calls often preserve all registers so that the call does not break
630 any live ranges in the caller side. This calling convention does not support
631 varargs and requires the prototype of all callees to exactly match the
632 prototype of the function definition.
633 </dd>
634
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]635 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]636
637 <dd>Any calling convention may be specified by number, allowing
638 target-specific calling conventions to be used. Target specific calling
639 conventions start at 64.
640 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]641</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]642
643<p>More calling conventions can be added/defined on an as-needed basis, to
644support pascal conventions or any other well-known target-independent
645convention.</p>
646
647</div>
648
649<!-- ======================================================================= -->
650<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]651 <a name="visibility">Visibility Styles</a>
652</div>
653
654<div class="doc_text">
655
656<p>
657All Global Variables and Functions have one of the following visibility styles:
658</p>
659
660<dl>
661 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
662
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]663 <dd>On targets that use the ELF object file format, default visibility means
664 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]665 modules and, in shared libraries, means that the declared entity may be
666 overridden. On Darwin, default visibility means that the declaration is
667 visible to other modules. Default visibility corresponds to "external
668 linkage" in the language.
669 </dd>
670
671 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
672
673 <dd>Two declarations of an object with hidden visibility refer to the same
674 object if they are in the same shared object. Usually, hidden visibility
675 indicates that the symbol will not be placed into the dynamic symbol table,
676 so no other module (executable or shared library) can reference it
677 directly.
678 </dd>
679
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]680 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
681
682 <dd>On ELF, protected visibility indicates that the symbol will be placed in
683 the dynamic symbol table, but that references within the defining module will
684 bind to the local symbol. That is, the symbol cannot be overridden by another
685 module.
686 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]687</dl>
688
689</div>
690
691<!-- ======================================================================= -->
692<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]693 <a name="namedtypes">Named Types</a>
694</div>
695
696<div class="doc_text">
697
698<p>LLVM IR allows you to specify name aliases for certain types. This can make
699it easier to read the IR and make the IR more condensed (particularly when
700recursive types are involved). An example of a name specification is:
701</p>
702
703<div class="doc_code">
704<pre>
705%mytype = type { %mytype*, i32 }
706</pre>
707</div>
708
709<p>You may give a name to any <a href="#typesystem">type</a> except "<a
710href="t_void">void</a>". Type name aliases may be used anywhere a type is
711expected with the syntax "%mytype".</p>
712
713<p>Note that type names are aliases for the structural type that they indicate,
714and that you can therefore specify multiple names for the same type. This often
715leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
716structural typing, the name is not part of the type. When printing out LLVM IR,
717the printer will pick <em>one name</em> to render all types of a particular
718shape. This means that if you have code where two different source types end up
719having the same LLVM type, that the dumper will sometimes print the "wrong" or
720unexpected type. This is an important design point and isn't going to
721change.</p>
722
723</div>
724
725
726<!-- ======================================================================= -->
727<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]728 <a name="globalvars">Global Variables</a>
729</div>
730
731<div class="doc_text">
732
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]733<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]734instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]735an explicit section to be placed in, and may have an optional explicit alignment
736specified. A variable may be defined as "thread_local", which means that it
737will not be shared by threads (each thread will have a separated copy of the
738variable). A variable may be defined as a global "constant," which indicates
739that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]740optimization, allowing the global data to be placed in the read-only section of
741an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]742cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]743
744<p>
745LLVM explicitly allows <em>declarations</em> of global variables to be marked
746constant, even if the final definition of the global is not. This capability
747can be used to enable slightly better optimization of the program, but requires
748the language definition to guarantee that optimizations based on the
749'constantness' are valid for the translation units that do not include the
750definition.
751</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]752
753<p>As SSA values, global variables define pointer values that are in
754scope (i.e. they dominate) all basic blocks in the program. Global
755variables always define a pointer to their "content" type because they
756describe a region of memory, and all memory objects in LLVM are
757accessed through pointers.</p>
758
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]759<p>A global variable may be declared to reside in a target-specifc numbered
760address space. For targets that support them, address spaces may affect how
761optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]762the variable. The default address space is zero. The address space qualifier
763must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]764
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]765<p>LLVM allows an explicit section to be specified for globals. If the target
766supports it, it will emit globals to the section specified.</p>
767
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]768<p>An explicit alignment may be specified for a global. If not present, or if
769the alignment is set to zero, the alignment of the global is set by the target
770to whatever it feels convenient. If an explicit alignment is specified, the
771global is forced to have at least that much alignment. All alignments must be
772a power of 2.</p>
773
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]774<p>For example, the following defines a global in a numbered address space with
775an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]776
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]777<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]778<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]779@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]780</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]781</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]782
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]783</div>
784
785
786<!-- ======================================================================= -->
787<div class="doc_subsection">
788 <a name="functionstructure">Functions</a>
789</div>
790
791<div class="doc_text">
792
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]793<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
794an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]795<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]796<a href="#callingconv">calling convention</a>, a return type, an optional
797<a href="#paramattrs">parameter attribute</a> for the return type, a function
798name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]799<a href="#paramattrs">parameter attributes</a>), optional
800<a href="#fnattrs">function attributes</a>, an optional section,
801an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]802an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]803
804LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
805optional <a href="#linkage">linkage type</a>, an optional
806<a href="#visibility">visibility style</a>, an optional
807<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]808<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]809name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]810<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]811
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]812<p>A function definition contains a list of basic blocks, forming the CFG
813(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]814the function. Each basic block may optionally start with a label (giving the
815basic block a symbol table entry), contains a list of instructions, and ends
816with a <a href="#terminators">terminator</a> instruction (such as a branch or
817function return).</p>
818
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]819<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]820executed on entrance to the function, and it is not allowed to have predecessor
821basic blocks (i.e. there can not be any branches to the entry block of a
822function). Because the block can have no predecessors, it also cannot have any
823<a href="#i_phi">PHI nodes</a>.</p>
824
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]825<p>LLVM allows an explicit section to be specified for functions. If the target
826supports it, it will emit functions to the section specified.</p>
827
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]828<p>An explicit alignment may be specified for a function. If not present, or if
829the alignment is set to zero, the alignment of the function is set by the target
830to whatever it feels convenient. If an explicit alignment is specified, the
831function is forced to have at least that much alignment. All alignments must be
832a power of 2.</p>
833
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]834 <h5>Syntax:</h5>
835
836<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]837<tt>
838define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
839 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
840 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
841 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
842 [<a href="#gc">gc</a>] { ... }
843</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]844</div>
845
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]846</div>
847
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]848
849<!-- ======================================================================= -->
850<div class="doc_subsection">
851 <a name="aliasstructure">Aliases</a>
852</div>
853<div class="doc_text">
854 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]855 function, global variable, another alias or bitcast of global value). Aliases
856 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]857 optional <a href="#visibility">visibility style</a>.</p>
858
859 <h5>Syntax:</h5>
860
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]861<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]862<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]863@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]864</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]865</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]866
867</div>
868
869
870
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]871<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]872<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
873<div class="doc_text">
874 <p>The return type and each parameter of a function type may have a set of
875 <i>parameter attributes</i> associated with them. Parameter attributes are
876 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]877 a function. Parameter attributes are considered to be part of the function,
878 not of the function type, so functions with different parameter attributes
879 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]880
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]881 <p>Parameter attributes are simple keywords that follow the type specified. If
882 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]883 example:</p>
884
885<div class="doc_code">
886<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]887declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]888declare i32 @atoi(i8 zeroext)
889declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]890</pre>
891</div>
892
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]893 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
894 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]895
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]896 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]897 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]898 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]899 <dd>This indicates to the code generator that the parameter or return value
900 should be zero-extended to a 32-bit value by the caller (for a parameter)
901 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]902
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]903 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]904 <dd>This indicates to the code generator that the parameter or return value
905 should be sign-extended to a 32-bit value by the caller (for a parameter)
906 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]907
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]908 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]909 <dd>This indicates that this parameter or return value should be treated
910 in a special target-dependent fashion during while emitting code for a
911 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]912 to memory, though some targets use it to distinguish between two different
913 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]914
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]915 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]916 <dd>This indicates that the pointer parameter should really be passed by
917 value to the function. The attribute implies that a hidden copy of the
918 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]919 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]920 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]921 value, but is also valid on pointers to scalars. The copy is considered to
922 belong to the caller not the callee (for example,
923 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]924 <tt>byval</tt> parameters). This is not a valid attribute for return
925 values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]926
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]927 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]928 <dd>This indicates that the pointer parameter specifies the address of a
929 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]930 This pointer must be guaranteed by the caller to be valid: loads and stores
931 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]932 be applied to the first parameter. This is not a valid attribute for
933 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]934
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]935 <dt><tt>noalias</tt></dt>
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]936 <dd>This indicates that the pointer does not alias any global or any other
937 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyd59572c2008-11-24 05:00:44 +0000[diff] [blame]938 case. On a function return value, <tt>noalias</tt> additionally indicates
939 that the pointer does not alias any other pointers visible to the
Nick Lewycky2abb1082008-12-19 06:39:12 +0000[diff] [blame]940 caller. For further details, please see the discussion of the NoAlias
941 response in
942 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
943 analysis</a>.</dd>
944
945 <dt><tt>nocapture</tt></dt>
946 <dd>This indicates that the callee does not make any copies of the pointer
947 that outlive the callee itself. This is not a valid attribute for return
948 values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]949
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]950 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]951 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]952 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
953 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]954 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]955
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]956</div>
957
958<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]959<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]960 <a name="gc">Garbage Collector Names</a>
961</div>
962
963<div class="doc_text">
964<p>Each function may specify a garbage collector name, which is simply a
965string.</p>
966
967<div class="doc_code"><pre
968>define void @f() gc "name" { ...</pre></div>
969
970<p>The compiler declares the supported values of <i>name</i>. Specifying a
971collector which will cause the compiler to alter its output in order to support
972the named garbage collection algorithm.</p>
973</div>
974
975<!-- ======================================================================= -->
976<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]977 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]978</div>
979
980<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]981
982<p>Function attributes are set to communicate additional information about
983 a function. Function attributes are considered to be part of the function,
984 not of the function type, so functions with different parameter attributes
985 can have the same function type.</p>
986
987 <p>Function attributes are simple keywords that follow the type specified. If
988 multiple attributes are needed, they are space separated. For
989 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]990
991<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]992<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]993define void @f() noinline { ... }
994define void @f() alwaysinline { ... }
995define void @f() alwaysinline optsize { ... }
996define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]997</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]998</div>
999
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1000<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1001<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1002<dd>This attribute indicates that the inliner should attempt to inline this
1003function into callers whenever possible, ignoring any active inlining size
1004threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1005
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1006<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1007<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]1008in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1009<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1010
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1011<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]1012<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1013make choices that keep the code size of this function low, and otherwise do
1014optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1015
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1016<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1017<dd>This function attribute indicates that the function never returns normally.
1018This produces undefined behavior at runtime if the function ever does
1019dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1020
1021<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1022<dd>This function attribute indicates that the function never returns with an
1023unwind or exceptional control flow. If the function does unwind, its runtime
1024behavior is undefined.</dd>
1025
1026<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1027<dd>This attribute indicates that the function computes its result (or the
1028exception it throws) based strictly on its arguments, without dereferencing any
1029pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1030registers, etc) visible to caller functions. It does not write through any
1031pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1032never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1033
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1034<dt><tt><a name="readonly">readonly</a></tt></dt>
1035<dd>This attribute indicates that the function does not write through any
1036pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1037or otherwise modify any state (e.g. memory, control registers, etc) visible to
1038caller functions. It may dereference pointer arguments and read state that may
1039be set in the caller. A readonly function always returns the same value (or
1040throws the same exception) when called with the same set of arguments and global
1041state.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1042
1043<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1044<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1045protector. It is in the form of a "canary"&mdash;a random value placed on the
1046stack before the local variables that's checked upon return from the function to
1047see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1048needs stack protectors or not.
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1049
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1050<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1051that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1052have an <tt>ssp</tt> attribute.</p></dd>
1053
1054<dt><tt>sspreq</tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1055<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1056stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1057function attribute.
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1058
1059<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1060function that doesn't have an <tt>sspreq</tt> attribute or which has
1061an <tt>ssp</tt> attribute, then the resulting function will have
1062an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1063</dl>
1064
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1065</div>
1066
1067<!-- ======================================================================= -->
1068<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1069 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1070</div>
1071
1072<div class="doc_text">
1073<p>
1074Modules may contain "module-level inline asm" blocks, which corresponds to the
1075GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1076LLVM and treated as a single unit, but may be separated in the .ll file if
1077desired. The syntax is very simple:
1078</p>
1079
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1080<div class="doc_code">
1081<pre>
1082module asm "inline asm code goes here"
1083module asm "more can go here"
1084</pre>
1085</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1086
1087<p>The strings can contain any character by escaping non-printable characters.
1088 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1089 for the number.
1090</p>
1091
1092<p>
1093 The inline asm code is simply printed to the machine code .s file when
1094 assembly code is generated.
1095</p>
1096</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1097
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1098<!-- ======================================================================= -->
1099<div class="doc_subsection">
1100 <a name="datalayout">Data Layout</a>
1101</div>
1102
1103<div class="doc_text">
1104<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1105data is to be laid out in memory. The syntax for the data layout is simply:</p>
1106<pre> target datalayout = "<i>layout specification</i>"</pre>
1107<p>The <i>layout specification</i> consists of a list of specifications
1108separated by the minus sign character ('-'). Each specification starts with a
1109letter and may include other information after the letter to define some
1110aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1111<dl>
1112 <dt><tt>E</tt></dt>
1113 <dd>Specifies that the target lays out data in big-endian form. That is, the
1114 bits with the most significance have the lowest address location.</dd>
1115 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1116 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1117 the bits with the least significance have the lowest address location.</dd>
1118 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1119 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1120 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1121 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1122 too.</dd>
1123 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1124 <dd>This specifies the alignment for an integer type of a given bit
1125 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1126 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1127 <dd>This specifies the alignment for a vector type of a given bit
1128 <i>size</i>.</dd>
1129 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1130 <dd>This specifies the alignment for a floating point type of a given bit
1131 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1132 (double).</dd>
1133 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1134 <dd>This specifies the alignment for an aggregate type of a given bit
1135 <i>size</i>.</dd>
1136</dl>
1137<p>When constructing the data layout for a given target, LLVM starts with a
1138default set of specifications which are then (possibly) overriden by the
1139specifications in the <tt>datalayout</tt> keyword. The default specifications
1140are given in this list:</p>
1141<ul>
1142 <li><tt>E</tt> - big endian</li>
1143 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1144 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1145 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1146 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1147 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1148 <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]1149 alignment of 64-bits</li>
1150 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1151 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1152 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1153 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1154 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1155</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1156<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1157following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1158<ol>
1159 <li>If the type sought is an exact match for one of the specifications, that
1160 specification is used.</li>
1161 <li>If no match is found, and the type sought is an integer type, then the
1162 smallest integer type that is larger than the bitwidth of the sought type is
1163 used. If none of the specifications are larger than the bitwidth then the the
1164 largest integer type is used. For example, given the default specifications
1165 above, the i7 type will use the alignment of i8 (next largest) while both
1166 i65 and i256 will use the alignment of i64 (largest specified).</li>
1167 <li>If no match is found, and the type sought is a vector type, then the
1168 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1169 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1170 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1171</ol>
1172</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1173
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1174<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1175<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1176<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1177
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1178<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1179
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1180<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1181intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1182optimizations to be performed on the intermediate representation directly,
1183without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1184extra analyses on the side before the transformation. A strong type
1185system makes it easier to read the generated code and enables novel
1186analyses and transformations that are not feasible to perform on normal
1187three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1188
1189</div>
1190
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1191<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1192<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1193Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1194<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1195<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1196classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1197
1198<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1199 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1200 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1201 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1202 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1203 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1204 </tr>
1205 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1206 <td><a href="#t_floating">floating point</a></td>
1207 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1208 </tr>
1209 <tr>
1210 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1211 <td><a href="#t_integer">integer</a>,
1212 <a href="#t_floating">floating point</a>,
1213 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1214 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1215 <a href="#t_struct">structure</a>,
1216 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1217 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1218 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1219 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1220 <tr>
1221 <td><a href="#t_primitive">primitive</a></td>
1222 <td><a href="#t_label">label</a>,
1223 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1224 <a href="#t_floating">floating point</a>.</td>
1225 </tr>
1226 <tr>
1227 <td><a href="#t_derived">derived</a></td>
1228 <td><a href="#t_integer">integer</a>,
1229 <a href="#t_array">array</a>,
1230 <a href="#t_function">function</a>,
1231 <a href="#t_pointer">pointer</a>,
1232 <a href="#t_struct">structure</a>,
1233 <a href="#t_pstruct">packed structure</a>,
1234 <a href="#t_vector">vector</a>,
1235 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1236 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1237 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1238 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1239</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1240
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1241<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1242most important. Values of these types are the only ones which can be
1243produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1244instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1245</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1246
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1247<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1248<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1249
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1250<div class="doc_text">
1251<p>The primitive types are the fundamental building blocks of the LLVM
1252system.</p>
1253
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1254</div>
1255
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1256<!-- _______________________________________________________________________ -->
1257<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1258
1259<div class="doc_text">
1260 <table>
1261 <tbody>
1262 <tr><th>Type</th><th>Description</th></tr>
1263 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1264 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1265 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1266 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1267 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1268 </tbody>
1269 </table>
1270</div>
1271
1272<!-- _______________________________________________________________________ -->
1273<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1274
1275<div class="doc_text">
1276<h5>Overview:</h5>
1277<p>The void type does not represent any value and has no size.</p>
1278
1279<h5>Syntax:</h5>
1280
1281<pre>
1282 void
1283</pre>
1284</div>
1285
1286<!-- _______________________________________________________________________ -->
1287<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1288
1289<div class="doc_text">
1290<h5>Overview:</h5>
1291<p>The label type represents code labels.</p>
1292
1293<h5>Syntax:</h5>
1294
1295<pre>
1296 label
1297</pre>
1298</div>
1299
1300
1301<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1302<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1303
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1304<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1305
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1306<p>The real power in LLVM comes from the derived types in the system.
1307This is what allows a programmer to represent arrays, functions,
1308pointers, and other useful types. Note that these derived types may be
1309recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1310
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1311</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1312
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1313<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1314<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1315
1316<div class="doc_text">
1317
1318<h5>Overview:</h5>
1319<p>The integer type is a very simple derived type that simply specifies an
1320arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13212^23-1 (about 8 million) can be specified.</p>
1322
1323<h5>Syntax:</h5>
1324
1325<pre>
1326 iN
1327</pre>
1328
1329<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1330value.</p>
1331
1332<h5>Examples:</h5>
1333<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1334 <tbody>
1335 <tr>
1336 <td><tt>i1</tt></td>
1337 <td>a single-bit integer.</td>
1338 </tr><tr>
1339 <td><tt>i32</tt></td>
1340 <td>a 32-bit integer.</td>
1341 </tr><tr>
1342 <td><tt>i1942652</tt></td>
1343 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1344 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1345 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1346</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1347</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1348
1349<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1350<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1351
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1352<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1353
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1354<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1355
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1356<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1357sequentially in memory. The array type requires a size (number of
1358elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1359
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1360<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1361
1362<pre>
1363 [&lt;# elements&gt; x &lt;elementtype&gt;]
1364</pre>
1365
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1366<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1367be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1368
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1369<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1370<table class="layout">
1371 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1372 <td class="left"><tt>[40 x i32]</tt></td>
1373 <td class="left">Array of 40 32-bit integer values.</td>
1374 </tr>
1375 <tr class="layout">
1376 <td class="left"><tt>[41 x i32]</tt></td>
1377 <td class="left">Array of 41 32-bit integer values.</td>
1378 </tr>
1379 <tr class="layout">
1380 <td class="left"><tt>[4 x i8]</tt></td>
1381 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1382 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1383</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1384<p>Here are some examples of multidimensional arrays:</p>
1385<table class="layout">
1386 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1387 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1388 <td class="left">3x4 array of 32-bit integer values.</td>
1389 </tr>
1390 <tr class="layout">
1391 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1392 <td class="left">12x10 array of single precision floating point values.</td>
1393 </tr>
1394 <tr class="layout">
1395 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1396 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1397 </tr>
1398</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1399
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1400<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1401length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1402LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1403As a special case, however, zero length arrays are recognized to be variable
1404length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1405type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1406
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1407</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1408
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1409<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1410<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1411<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1412
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1413<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1414
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1415<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1416consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1417return 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]1418If 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]1419class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1420
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1421<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1422
1423<pre>
1424 &lt;returntype list&gt; (&lt;parameter list&gt;)
1425</pre>
1426
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1427<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]1428specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1429which indicates that the function takes a variable number of arguments.
1430Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1431 href="#int_varargs">variable argument handling intrinsic</a> functions.
1432'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1433<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1434
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1435<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1436<table class="layout">
1437 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1438 <td class="left"><tt>i32 (i32)</tt></td>
1439 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1440 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1441 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1442 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1443 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1444 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1445 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1446 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1447 <tt>float</tt>.
1448 </td>
1449 </tr><tr class="layout">
1450 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1451 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1452 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1453 which returns an integer. This is the signature for <tt>printf</tt> in
1454 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1455 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1456 </tr><tr class="layout">
1457 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1458 <td class="left">A function taking an <tt>i32</tt>, returning two
1459 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1460 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1461 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1462</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1463
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1464</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1465<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1466<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1467<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1468<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1469<p>The structure type is used to represent a collection of data members
1470together in memory. The packing of the field types is defined to match
1471the ABI of the underlying processor. The elements of a structure may
1472be any type that has a size.</p>
1473<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1474and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1475field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1476instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1477<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1478<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1479<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1480<table class="layout">
1481 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1482 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1483 <td class="left">A triple of three <tt>i32</tt> values</td>
1484 </tr><tr class="layout">
1485 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1486 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1487 second element is a <a href="#t_pointer">pointer</a> to a
1488 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1489 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1490 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1491</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1492</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1493
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1494<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1495<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1496</div>
1497<div class="doc_text">
1498<h5>Overview:</h5>
1499<p>The packed structure type is used to represent a collection of data members
1500together in memory. There is no padding between fields. Further, the alignment
1501of a packed structure is 1 byte. The elements of a packed structure may
1502be any type that has a size.</p>
1503<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1504and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1505field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1506instruction.</p>
1507<h5>Syntax:</h5>
1508<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1509<h5>Examples:</h5>
1510<table class="layout">
1511 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1512 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1513 <td class="left">A triple of three <tt>i32</tt> values</td>
1514 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1515 <td class="left">
1516<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1517 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1518 second element is a <a href="#t_pointer">pointer</a> to a
1519 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1520 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1521 </tr>
1522</table>
1523</div>
1524
1525<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1526<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1527<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1528<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1529<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1530reference to another object, which must live in memory. Pointer types may have
1531an optional address space attribute defining the target-specific numbered
1532address space where the pointed-to object resides. The default address space is
1533zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1534<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1535<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1536<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1537<table class="layout">
1538 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1539 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1540 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1541 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1542 </tr>
1543 <tr class="layout">
1544 <td class="left"><tt>i32 (i32 *) *</tt></td>
1545 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1546 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1547 <tt>i32</tt>.</td>
1548 </tr>
1549 <tr class="layout">
1550 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1551 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1552 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1553 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1554</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1555</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1556
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1557<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1558<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1559<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1560
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1561<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1562
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1563<p>A vector type is a simple derived type that represents a vector
1564of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1565are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1566A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1567elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1568of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1569considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1570
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1571<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1572
1573<pre>
1574 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1575</pre>
1576
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1577<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1578be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1579
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1580<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1581
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1582<table class="layout">
1583 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1584 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1585 <td class="left">Vector of 4 32-bit integer values.</td>
1586 </tr>
1587 <tr class="layout">
1588 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1589 <td class="left">Vector of 8 32-bit floating-point values.</td>
1590 </tr>
1591 <tr class="layout">
1592 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1593 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1594 </tr>
1595</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1596</div>
1597
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1598<!-- _______________________________________________________________________ -->
1599<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1600<div class="doc_text">
1601
1602<h5>Overview:</h5>
1603
1604<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1605corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1606In LLVM, opaque types can eventually be resolved to any type (not just a
1607structure type).</p>
1608
1609<h5>Syntax:</h5>
1610
1611<pre>
1612 opaque
1613</pre>
1614
1615<h5>Examples:</h5>
1616
1617<table class="layout">
1618 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1619 <td class="left"><tt>opaque</tt></td>
1620 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1621 </tr>
1622</table>
1623</div>
1624
1625
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1626<!-- *********************************************************************** -->
1627<div class="doc_section"> <a name="constants">Constants</a> </div>
1628<!-- *********************************************************************** -->
1629
1630<div class="doc_text">
1631
1632<p>LLVM has several different basic types of constants. This section describes
1633them all and their syntax.</p>
1634
1635</div>
1636
1637<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1638<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1639
1640<div class="doc_text">
1641
1642<dl>
1643 <dt><b>Boolean constants</b></dt>
1644
1645 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1646 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1647 </dd>
1648
1649 <dt><b>Integer constants</b></dt>
1650
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1651 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1652 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1653 integer types.
1654 </dd>
1655
1656 <dt><b>Floating point constants</b></dt>
1657
1658 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1659 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1660 notation (see below). The assembler requires the exact decimal value of
1661 a floating-point constant. For example, the assembler accepts 1.25 but
1662 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1663 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1664
1665 <dt><b>Null pointer constants</b></dt>
1666
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1667 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1668 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1669
1670</dl>
1671
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1672<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1673of floating point constants. For example, the form '<tt>double
16740x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16754.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1676(and the only time that they are generated by the disassembler) is when a
1677floating point constant must be emitted but it cannot be represented as a
1678decimal floating point number. For example, NaN's, infinities, and other
1679special values are represented in their IEEE hexadecimal format so that
1680assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1681
1682</div>
1683
1684<!-- ======================================================================= -->
1685<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1686</div>
1687
1688<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1689<p>Aggregate constants arise from aggregation of simple constants
1690and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1691
1692<dl>
1693 <dt><b>Structure constants</b></dt>
1694
1695 <dd>Structure constants are represented with notation similar to structure
1696 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1697 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1698 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]1699 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1700 types of elements must match those specified by the type.
1701 </dd>
1702
1703 <dt><b>Array constants</b></dt>
1704
1705 <dd>Array constants are represented with notation similar to array type
1706 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1707 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1708 constants must have <a href="#t_array">array type</a>, and the number and
1709 types of elements must match those specified by the type.
1710 </dd>
1711
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1712 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1713
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1714 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1715 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1716 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]1717 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1718 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1719 match those specified by the type.
1720 </dd>
1721
1722 <dt><b>Zero initialization</b></dt>
1723
1724 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1725 value to zero of <em>any</em> type, including scalar and aggregate types.
1726 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]1727 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1728 initializers.
1729 </dd>
1730</dl>
1731
1732</div>
1733
1734<!-- ======================================================================= -->
1735<div class="doc_subsection">
1736 <a name="globalconstants">Global Variable and Function Addresses</a>
1737</div>
1738
1739<div class="doc_text">
1740
1741<p>The addresses of <a href="#globalvars">global variables</a> and <a
1742href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1743constants. These constants are explicitly referenced when the <a
1744href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1745href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1746file:</p>
1747
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1748<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1749<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1750@X = global i32 17
1751@Y = global i32 42
1752@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1753</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1754</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1755
1756</div>
1757
1758<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1759<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1760<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1761 <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]1762 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1763 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1764
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1765 <p>Undefined values indicate to the compiler that the program is well defined
1766 no matter what value is used, giving the compiler more freedom to optimize.
1767 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1768</div>
1769
1770<!-- ======================================================================= -->
1771<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1772</div>
1773
1774<div class="doc_text">
1775
1776<p>Constant expressions are used to allow expressions involving other constants
1777to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1778href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1779that does not have side effects (e.g. load and call are not supported). The
1780following is the syntax for constant expressions:</p>
1781
1782<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1783 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1784 <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]1785 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1786
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1787 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1788 <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]1789 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]1790
1791 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1792 <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]1793 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]1794
1795 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1796 <dd>Truncate a floating point constant to another floating point type. The
1797 size of CST must be larger than the size of TYPE. Both types must be
1798 floating point.</dd>
1799
1800 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1801 <dd>Floating point extend a constant to another type. The size of CST must be
1802 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1803
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1804 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1805 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1806 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1807 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1808 of the same number of elements. If the value won't fit in the integer type,
1809 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1810
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1811 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1812 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1813 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1814 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1815 of the same number of elements. If the value won't fit in the integer type,
1816 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1817
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1818 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1819 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1820 constant. TYPE must be a scalar or vector floating point type. CST must be of
1821 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1822 of the same number of elements. If the value won't fit in the floating point
1823 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1824
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1825 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1826 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1827 constant. TYPE must be a scalar or vector floating point type. CST must be of
1828 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1829 of the same number of elements. If the value won't fit in the floating point
1830 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1831
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1832 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1833 <dd>Convert a pointer typed constant to the corresponding integer constant
1834 TYPE must be an integer type. CST must be of pointer type. The CST value is
1835 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1836
1837 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1838 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1839 pointer type. CST must be of integer type. The CST value is zero extended,
1840 truncated, or unchanged to make it fit in a pointer size. This one is
1841 <i>really</i> dangerous!</dd>
1842
1843 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1844 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1845 identical (same number of bits). The conversion is done as if the CST value
1846 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]1847 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1848 vector types to any other type, as long as they have the same bit width. For
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]1849 pointers it is only valid to cast to another pointer type. It is not valid
1850 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1851 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1852
1853 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1854
1855 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1856 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1857 instruction, the index list may have zero or more indexes, which are required
1858 to make sense for the type of "CSTPTR".</dd>
1859
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1860 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1861
1862 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1863 constants.</dd>
1864
1865 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1866 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1867
1868 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1869 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1870
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1871 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1872 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1873
1874 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1875 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1876
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1877 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1878
1879 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1880 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1881
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1882 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1883
1884 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1885 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1886
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1887
1888 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1889
1890 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1891 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1892
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1893 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1894
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1895 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1896 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1897 binary</a> operations. The constraints on operands are the same as those for
1898 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1899 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1900</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1901</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1902
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1903<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1904<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1905<!-- *********************************************************************** -->
1906
1907<!-- ======================================================================= -->
1908<div class="doc_subsection">
1909<a name="inlineasm">Inline Assembler Expressions</a>
1910</div>
1911
1912<div class="doc_text">
1913
1914<p>
1915LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1916Module-Level Inline Assembly</a>) through the use of a special value. This
1917value represents the inline assembler as a string (containing the instructions
1918to emit), a list of operand constraints (stored as a string), and a flag that
1919indicates whether or not the inline asm expression has side effects. An example
1920inline assembler expression is:
1921</p>
1922
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1923<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1924<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1925i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1926</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1927</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1928
1929<p>
1930Inline assembler expressions may <b>only</b> be used as the callee operand of
1931a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1932</p>
1933
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1934<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1935<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1936%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]1937</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1938</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1939
1940<p>
1941Inline asms with side effects not visible in the constraint list must be marked
1942as having side effects. This is done through the use of the
1943'<tt>sideeffect</tt>' keyword, like so:
1944</p>
1945
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1946<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1947<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1948call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1949</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1950</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1951
1952<p>TODO: The format of the asm and constraints string still need to be
1953documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]1954need to be documented). This is probably best done by reference to another
1955document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1956</p>
1957
1958</div>
1959
1960<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1961<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1962<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1963
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1964<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1965
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1966<p>The LLVM instruction set consists of several different
1967classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1968instructions</a>, <a href="#binaryops">binary instructions</a>,
1969<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1970 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1971instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1972
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1973</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1974
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1975<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1976<div class="doc_subsection"> <a name="terminators">Terminator
1977Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1978
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1979<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1980
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1981<p>As mentioned <a href="#functionstructure">previously</a>, every
1982basic block in a program ends with a "Terminator" instruction, which
1983indicates which block should be executed after the current block is
1984finished. These terminator instructions typically yield a '<tt>void</tt>'
1985value: they produce control flow, not values (the one exception being
1986the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1987<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1988 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1989instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1990the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1991 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1992 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1993
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1994</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1995
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1996<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1997<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1998Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1999<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2000<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2001<pre>
2002 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]2003 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2004</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2005
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2006<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2007
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2008<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2009optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]2010<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2011returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2012control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2013
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2014<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2015
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2016<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2017the return value. The type of the return value must be a
2018'<a href="#t_firstclass">first class</a>' type.</p>
2019
2020<p>A function is not <a href="#wellformed">well formed</a> if
2021it it has a non-void return type and contains a '<tt>ret</tt>'
2022instruction with no return value or a return value with a type that
2023does not match its type, or if it has a void return type and contains
2024a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2025
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2026<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2027
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2028<p>When the '<tt>ret</tt>' instruction is executed, control flow
2029returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]2030 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2031the instruction after the call. If the caller was an "<a
2032 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2033at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2034returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2035return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2036
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2037<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2038
2039<pre>
2040 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2041 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2042 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]2043</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2044
2045<p>Note that the code generator does not yet fully support larger
2046 aggregate return values.</p>
2047
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2048</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2049<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2050<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2051<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2052<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2053<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]2054</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2055<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2056<p>The '<tt>br</tt>' instruction is used to cause control flow to
2057transfer to a different basic block in the current function. There are
2058two forms of this instruction, corresponding to a conditional branch
2059and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2060<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2061<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2062single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]2063unconditional form of the '<tt>br</tt>' instruction takes a single
2064'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2065<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2066<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2067argument is evaluated. If the value is <tt>true</tt>, control flows
2068to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2069control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2070<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2071<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]2072 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]2073</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2074<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2075<div class="doc_subsubsection">
2076 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2077</div>
2078
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2079<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2080<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2081
2082<pre>
2083 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2084</pre>
2085
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2086<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2087
2088<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2089several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2090instruction, allowing a branch to occur to one of many possible
2091destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2092
2093
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2094<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2095
2096<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2097comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2098an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2099table is not allowed to contain duplicate constant entries.</p>
2100
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2101<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2102
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2103<p>The <tt>switch</tt> instruction specifies a table of values and
2104destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2105table is searched for the given value. If the value is found, control flow is
2106transfered to the corresponding destination; otherwise, control flow is
2107transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2108
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2109<h5>Implementation:</h5>
2110
2111<p>Depending on properties of the target machine and the particular
2112<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2113ways. For example, it could be generated as a series of chained conditional
2114branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2115
2116<h5>Example:</h5>
2117
2118<pre>
2119 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2120 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2121 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2122
2123 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2124 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2125
2126 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2127 switch i32 %val, label %otherwise [ i32 0, label %onzero
2128 i32 1, label %onone
2129 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2130</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2131</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2132
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2133<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2134<div class="doc_subsubsection">
2135 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2136</div>
2137
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2138<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2139
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2140<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2141
2142<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2143 &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]2144 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2145</pre>
2146
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2147<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2148
2149<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2150function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2151'<tt>normal</tt>' label or the
2152'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2153"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2154"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2155href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2156continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2157
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2158<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2159
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2160<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2161
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2162<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2163 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2164 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2165 convention</a> the call should use. If none is specified, the call defaults
2166 to using C calling conventions.
2167 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2168
2169 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2170 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2171 and '<tt>inreg</tt>' attributes are valid here.</li>
2172
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2173 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2174 function value being invoked. In most cases, this is a direct function
2175 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2176 an arbitrary pointer to function value.
2177 </li>
2178
2179 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2180 function to be invoked. </li>
2181
2182 <li>'<tt>function args</tt>': argument list whose types match the function
2183 signature argument types. If the function signature indicates the function
2184 accepts a variable number of arguments, the extra arguments can be
2185 specified. </li>
2186
2187 <li>'<tt>normal label</tt>': the label reached when the called function
2188 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2189
2190 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2191 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2192
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2193 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2194 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2195 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2196</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2198<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2199
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2200<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2201href="#i_call">call</a></tt>' instruction in most regards. The primary
2202difference is that it establishes an association with a label, which is used by
2203the runtime library to unwind the stack.</p>
2204
2205<p>This instruction is used in languages with destructors to ensure that proper
2206cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2207exception. Additionally, this is important for implementation of
2208'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2209
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2210<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2211<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2212 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2213 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2214 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2215 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2216</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2217</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2218
2219
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2220<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2221
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2222<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2223Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2224
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2225<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2226
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2227<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2228<pre>
2229 unwind
2230</pre>
2231
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2232<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2233
2234<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2235at the first callee in the dynamic call stack which used an <a
2236href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2237primarily used to implement exception handling.</p>
2238
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2239<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2240
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2241<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2242immediately halt. The dynamic call stack is then searched for the first <a
2243href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2244execution continues at the "exceptional" destination block specified by the
2245<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2246dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2247</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2248
2249<!-- _______________________________________________________________________ -->
2250
2251<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2252Instruction</a> </div>
2253
2254<div class="doc_text">
2255
2256<h5>Syntax:</h5>
2257<pre>
2258 unreachable
2259</pre>
2260
2261<h5>Overview:</h5>
2262
2263<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2264instruction is used to inform the optimizer that a particular portion of the
2265code is not reachable. This can be used to indicate that the code after a
2266no-return function cannot be reached, and other facts.</p>
2267
2268<h5>Semantics:</h5>
2269
2270<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2271</div>
2272
2273
2274
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2275<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2276<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2277<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2278<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2279program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2280produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2281multiple 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]2282The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2283<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2284</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2285<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2286<div class="doc_subsubsection">
2287 <a name="i_add">'<tt>add</tt>' Instruction</a>
2288</div>
2289
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2290<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2291
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2292<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2293
2294<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2295 &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]2296</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2297
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2298<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2299
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2300<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2301
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2302<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2303
2304<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2305 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2306 <a href="#t_vector">vector</a> values. Both arguments must have identical
2307 types.</p>
2308
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2309<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2310
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2311<p>The value produced is the integer or floating point sum of the two
2312operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2313
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2314<p>If an integer sum has unsigned overflow, the result returned is the
2315mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2316the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2317
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2318<p>Because LLVM integers use a two's complement representation, this
2319instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2321<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2322
2323<pre>
2324 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2325</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2326</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2327<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2328<div class="doc_subsubsection">
2329 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2330</div>
2331
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2332<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2333
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2334<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2335
2336<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2337 &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]2338</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2339
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2340<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2341
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2342<p>The '<tt>sub</tt>' instruction returns the difference of its two
2343operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2344
2345<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2346'<tt>neg</tt>' instruction present in most other intermediate
2347representations.</p>
2348
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2349<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2350
2351<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2352 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2353 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2354 types.</p>
2355
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2356<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2357
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2358<p>The value produced is the integer or floating point difference of
2359the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2360
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2361<p>If an integer difference has unsigned overflow, the result returned is the
2362mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2363the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2364
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2365<p>Because LLVM integers use a two's complement representation, this
2366instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2367
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2368<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2369<pre>
2370 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2371 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2372</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2373</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2374
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2375<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2376<div class="doc_subsubsection">
2377 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2378</div>
2379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2380<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2381
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2382<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2383<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]2384</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2385<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2386<p>The '<tt>mul</tt>' instruction returns the product of its two
2387operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2389<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2390
2391<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2392href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2393or <a href="#t_vector">vector</a> values. Both arguments must have identical
2394types.</p>
2395
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2396<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2397
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2398<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2399two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2400
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2401<p>If the result of an integer multiplication has unsigned overflow,
2402the result returned is the mathematical result modulo
24032<sup>n</sup>, where n is the bit width of the result.</p>
2404<p>Because LLVM integers use a two's complement representation, and the
2405result is the same width as the operands, this instruction returns the
2406correct result for both signed and unsigned integers. If a full product
2407(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2408should be sign-extended or zero-extended as appropriate to the
2409width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2410<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2411<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]2412</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2413</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2414
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2415<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2416<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2417</a></div>
2418<div class="doc_text">
2419<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2420<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]2421</pre>
2422<h5>Overview:</h5>
2423<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2424operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2425
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2426<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2427
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2428<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2429<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2430values. Both arguments must have identical types.</p>
2431
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2432<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2433
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2434<p>The value produced is the unsigned integer quotient of the two operands.</p>
2435<p>Note that unsigned integer division and signed integer division are distinct
2436operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2437<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2438<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2439<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]2440</pre>
2441</div>
2442<!-- _______________________________________________________________________ -->
2443<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2444</a> </div>
2445<div class="doc_text">
2446<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2447<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2448 &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]2449</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2450
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2451<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2452
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2453<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2454operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2455
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2456<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2457
2458<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2459<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2460values. Both arguments must have identical types.</p>
2461
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2462<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2463<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]2464<p>Note that signed integer division and unsigned integer division are distinct
2465operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2466<p>Division by zero leads to undefined behavior. Overflow also leads to
2467undefined behavior; this is a rare case, but can occur, for example,
2468by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2469<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2470<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]2471</pre>
2472</div>
2473<!-- _______________________________________________________________________ -->
2474<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2475Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2476<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2477<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2478<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2479 &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]2480</pre>
2481<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2482
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2483<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2484operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2485
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2486<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2487
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2488<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2489<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2490of floating point values. Both arguments must have identical types.</p>
2491
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2492<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2493
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2494<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2495
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2496<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2497
2498<pre>
2499 &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]2500</pre>
2501</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2502
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2503<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2504<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2505</div>
2506<div class="doc_text">
2507<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2508<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]2509</pre>
2510<h5>Overview:</h5>
2511<p>The '<tt>urem</tt>' instruction returns the remainder from the
2512unsigned division of its two arguments.</p>
2513<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2514<p>The two arguments to the '<tt>urem</tt>' instruction must be
2515<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2516values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2517<h5>Semantics:</h5>
2518<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2519This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2520<p>Note that unsigned integer remainder and signed integer remainder are
2521distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2522<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2523<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2524<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]2525</pre>
2526
2527</div>
2528<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2529<div class="doc_subsubsection">
2530 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2531</div>
2532
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2533<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2534
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2535<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2536
2537<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2538 &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]2539</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2540
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2541<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2542
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2543<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2544signed division of its two operands. This instruction can also take
2545<a href="#t_vector">vector</a> versions of the values in which case
2546the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2547
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2548<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2549
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2550<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2551<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2552values. Both arguments must have identical types.</p>
2553
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2554<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2555
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2556<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2557has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2558operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2559a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2560 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2561Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2562please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2563Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2564<p>Note that signed integer remainder and unsigned integer remainder are
2565distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2566<p>Taking the remainder of a division by zero leads to undefined behavior.
2567Overflow also leads to undefined behavior; this is a rare case, but can occur,
2568for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2569(The remainder doesn't actually overflow, but this rule lets srem be
2570implemented using instructions that return both the result of the division
2571and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2572<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2573<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]2574</pre>
2575
2576</div>
2577<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2578<div class="doc_subsubsection">
2579 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2580
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2581<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2582
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2583<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2584<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]2585</pre>
2586<h5>Overview:</h5>
2587<p>The '<tt>frem</tt>' instruction returns the remainder from the
2588division of its two operands.</p>
2589<h5>Arguments:</h5>
2590<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2591<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2592of floating point values. Both arguments must have identical types.</p>
2593
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2594<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2595
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2596<p>This instruction returns the <i>remainder</i> of a division.
2597The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2598
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2599<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2600
2601<pre>
2602 &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]2603</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2604</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2605
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2606<!-- ======================================================================= -->
2607<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2608Operations</a> </div>
2609<div class="doc_text">
2610<p>Bitwise binary operators are used to do various forms of
2611bit-twiddling in a program. They are generally very efficient
2612instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2613instructions. They require two operands of the same type, execute an operation on them,
2614and 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]2615</div>
2616
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2617<!-- _______________________________________________________________________ -->
2618<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2619Instruction</a> </div>
2620<div class="doc_text">
2621<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2622<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]2623</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2624
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2625<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2626
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2627<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2628the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2629
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2630<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2631
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2632<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2633 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2634type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2635
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2636<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2637
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2638<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2639where 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]2640equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2641If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2642corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2643
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2644<h5>Example:</h5><pre>
2645 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2646 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2647 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2648 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2649 &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]2650</pre>
2651</div>
2652<!-- _______________________________________________________________________ -->
2653<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2654Instruction</a> </div>
2655<div class="doc_text">
2656<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2657<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]2658</pre>
2659
2660<h5>Overview:</h5>
2661<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2662operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2663
2664<h5>Arguments:</h5>
2665<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2666<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]2667type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2668
2669<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2670
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2671<p>This instruction always performs a logical shift right operation. The most
2672significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2673shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2674the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2675vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2676amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2677
2678<h5>Example:</h5>
2679<pre>
2680 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2681 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2682 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2683 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2684 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2685 &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]2686</pre>
2687</div>
2688
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2689<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2690<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2691Instruction</a> </div>
2692<div class="doc_text">
2693
2694<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2695<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]2696</pre>
2697
2698<h5>Overview:</h5>
2699<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2700operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2701
2702<h5>Arguments:</h5>
2703<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2704<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]2705type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2706
2707<h5>Semantics:</h5>
2708<p>This instruction always performs an arithmetic shift right operation,
2709The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2710of <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]2711larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2712arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2713corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2714
2715<h5>Example:</h5>
2716<pre>
2717 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2718 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2719 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2720 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2721 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2722 &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]2723</pre>
2724</div>
2725
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2726<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2727<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2728Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2729
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2730<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2731
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2733
2734<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2735 &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]2736</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2737
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2738<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2739
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2740<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2741its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2742
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2743<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2744
2745<p>The two arguments to the '<tt>and</tt>' instruction must be
2746<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2747values. Both arguments must have identical types.</p>
2748
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2749<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2750<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2751<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2752<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2753<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2754 <tbody>
2755 <tr>
2756 <td>In0</td>
2757 <td>In1</td>
2758 <td>Out</td>
2759 </tr>
2760 <tr>
2761 <td>0</td>
2762 <td>0</td>
2763 <td>0</td>
2764 </tr>
2765 <tr>
2766 <td>0</td>
2767 <td>1</td>
2768 <td>0</td>
2769 </tr>
2770 <tr>
2771 <td>1</td>
2772 <td>0</td>
2773 <td>0</td>
2774 </tr>
2775 <tr>
2776 <td>1</td>
2777 <td>1</td>
2778 <td>1</td>
2779 </tr>
2780 </tbody>
2781</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2782</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2783<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2784<pre>
2785 &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]2786 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2787 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2788</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2789</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2790<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2791<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2792<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2793<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2794<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]2795</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2796<h5>Overview:</h5>
2797<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2798or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2799<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2800
2801<p>The two arguments to the '<tt>or</tt>' instruction must be
2802<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2803values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2804<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2805<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2806<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2807<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2808<table border="1" cellspacing="0" cellpadding="4">
2809 <tbody>
2810 <tr>
2811 <td>In0</td>
2812 <td>In1</td>
2813 <td>Out</td>
2814 </tr>
2815 <tr>
2816 <td>0</td>
2817 <td>0</td>
2818 <td>0</td>
2819 </tr>
2820 <tr>
2821 <td>0</td>
2822 <td>1</td>
2823 <td>1</td>
2824 </tr>
2825 <tr>
2826 <td>1</td>
2827 <td>0</td>
2828 <td>1</td>
2829 </tr>
2830 <tr>
2831 <td>1</td>
2832 <td>1</td>
2833 <td>1</td>
2834 </tr>
2835 </tbody>
2836</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2837</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2838<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2839<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2840 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2841 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2842</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2843</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2844<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2845<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2846Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2847<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2848<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2849<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]2850</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2851<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2852<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2853or of its two operands. The <tt>xor</tt> is used to implement the
2854"one's complement" operation, which is the "~" operator in C.</p>
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<p>The two arguments to the '<tt>xor</tt>' instruction must be
2857<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2858values. Both arguments must have identical types.</p>
2859
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2860<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2861
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2862<p>The truth table used for the '<tt>xor</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>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2865<table border="1" cellspacing="0" cellpadding="4">
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>1</td>
2881 </tr>
2882 <tr>
2883 <td>1</td>
2884 <td>0</td>
2885 <td>1</td>
2886 </tr>
2887 <tr>
2888 <td>1</td>
2889 <td>1</td>
2890 <td>0</td>
2891 </tr>
2892 </tbody>
2893</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2894</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2895<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2896<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2897<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2898 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2899 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2900 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2901</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2902</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2903
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2904<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2905<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2906 <a name="vectorops">Vector Operations</a>
2907</div>
2908
2909<div class="doc_text">
2910
2911<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2912target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2913vector-specific operations needed to process vectors effectively. While LLVM
2914does directly support these vector operations, many sophisticated algorithms
2915will want to use target-specific intrinsics to take full advantage of a specific
2916target.</p>
2917
2918</div>
2919
2920<!-- _______________________________________________________________________ -->
2921<div class="doc_subsubsection">
2922 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2923</div>
2924
2925<div class="doc_text">
2926
2927<h5>Syntax:</h5>
2928
2929<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2930 &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]2931</pre>
2932
2933<h5>Overview:</h5>
2934
2935<p>
2936The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2937element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2938</p>
2939
2940
2941<h5>Arguments:</h5>
2942
2943<p>
2944The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2945value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2946an index indicating the position from which to extract the element.
2947The index may be a variable.</p>
2948
2949<h5>Semantics:</h5>
2950
2951<p>
2952The result is a scalar of the same type as the element type of
2953<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2954<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2955results are undefined.
2956</p>
2957
2958<h5>Example:</h5>
2959
2960<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2961 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2962</pre>
2963</div>
2964
2965
2966<!-- _______________________________________________________________________ -->
2967<div class="doc_subsubsection">
2968 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2969</div>
2970
2971<div class="doc_text">
2972
2973<h5>Syntax:</h5>
2974
2975<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2976 &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]2977</pre>
2978
2979<h5>Overview:</h5>
2980
2981<p>
2982The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2983element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2984</p>
2985
2986
2987<h5>Arguments:</h5>
2988
2989<p>
2990The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2991value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2992scalar value whose type must equal the element type of the first
2993operand. The third operand is an index indicating the position at
2994which to insert the value. The index may be a variable.</p>
2995
2996<h5>Semantics:</h5>
2997
2998<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2999The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3000element values are those of <tt>val</tt> except at position
3001<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3002exceeds the length of <tt>val</tt>, the results are undefined.
3003</p>
3004
3005<h5>Example:</h5>
3006
3007<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3008 %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]3009</pre>
3010</div>
3011
3012<!-- _______________________________________________________________________ -->
3013<div class="doc_subsubsection">
3014 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3015</div>
3016
3017<div class="doc_text">
3018
3019<h5>Syntax:</h5>
3020
3021<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3022 &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]3023</pre>
3024
3025<h5>Overview:</h5>
3026
3027<p>
3028The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3029from two input vectors, returning a vector with the same element type as
3030the input and length that is the same as the shuffle mask.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3031</p>
3032
3033<h5>Arguments:</h5>
3034
3035<p>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3036The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3037with types that match each other. The third argument is a shuffle mask whose
3038element type is always 'i32'. The result of the instruction is a vector whose
3039length is the same as the shuffle mask and whose element type is the same as
3040the element type of the first two operands.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3041</p>
3042
3043<p>
3044The shuffle mask operand is required to be a constant vector with either
3045constant integer or undef values.
3046</p>
3047
3048<h5>Semantics:</h5>
3049
3050<p>
3051The elements of the two input vectors are numbered from left to right across
3052both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3053the result vector, which element of the two input vectors the result element
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3054gets. The element selector may be undef (meaning "don't care") and the second
3055operand may be undef if performing a shuffle from only one vector.
3056</p>
3057
3058<h5>Example:</h5>
3059
3060<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3061 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3062 &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]3063 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3064 &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]3065 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3066 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3067 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3068 &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]3069</pre>
3070</div>
3071
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3072
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3073<!-- ======================================================================= -->
3074<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3075 <a name="aggregateops">Aggregate Operations</a>
3076</div>
3077
3078<div class="doc_text">
3079
3080<p>LLVM supports several instructions for working with aggregate values.
3081</p>
3082
3083</div>
3084
3085<!-- _______________________________________________________________________ -->
3086<div class="doc_subsubsection">
3087 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3088</div>
3089
3090<div class="doc_text">
3091
3092<h5>Syntax:</h5>
3093
3094<pre>
3095 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3096</pre>
3097
3098<h5>Overview:</h5>
3099
3100<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3101The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3102or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3103</p>
3104
3105
3106<h5>Arguments:</h5>
3107
3108<p>
3109The first operand of an '<tt>extractvalue</tt>' instruction is a
3110value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3111type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3112in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3113'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3114</p>
3115
3116<h5>Semantics:</h5>
3117
3118<p>
3119The result is the value at the position in the aggregate specified by
3120the index operands.
3121</p>
3122
3123<h5>Example:</h5>
3124
3125<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3126 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3127</pre>
3128</div>
3129
3130
3131<!-- _______________________________________________________________________ -->
3132<div class="doc_subsubsection">
3133 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3134</div>
3135
3136<div class="doc_text">
3137
3138<h5>Syntax:</h5>
3139
3140<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3141 &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]3142</pre>
3143
3144<h5>Overview:</h5>
3145
3146<p>
3147The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3148into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3149</p>
3150
3151
3152<h5>Arguments:</h5>
3153
3154<p>
3155The first operand of an '<tt>insertvalue</tt>' instruction is a
3156value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3157The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3158The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3159indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3160indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3161'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3162The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3163by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3164</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3165
3166<h5>Semantics:</h5>
3167
3168<p>
3169The result is an aggregate of the same type as <tt>val</tt>. Its
3170value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3171specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3172</p>
3173
3174<h5>Example:</h5>
3175
3176<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3177 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3178</pre>
3179</div>
3180
3181
3182<!-- ======================================================================= -->
3183<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3184 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3185</div>
3186
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3187<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3188
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3189<p>A key design point of an SSA-based representation is how it
3190represents memory. In LLVM, no memory locations are in SSA form, which
3191makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3192allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3193
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3194</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3195
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3196<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3197<div class="doc_subsubsection">
3198 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3199</div>
3200
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3201<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3202
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3203<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3204
3205<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3206 &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]3207</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3208
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3209<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3210
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3211<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3212heap and returns a pointer to it. The object is always allocated in the generic
3213address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3214
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3215<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3216
3217<p>The '<tt>malloc</tt>' instruction allocates
3218<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3219bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3220appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3221number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3222If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3223be aligned to at least that boundary. If not specified, or if zero, the target can
3224choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3225
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3226<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3227
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3228<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3229
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3230<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]3231a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3232result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3233
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3234<h5>Example:</h5>
3235
3236<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3237 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3238
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3239 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3240 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3241 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3242 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3243 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3244</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3245
3246<p>Note that the code generator does not yet respect the
3247 alignment value.</p>
3248
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3249</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3250
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3251<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3252<div class="doc_subsubsection">
3253 <a name="i_free">'<tt>free</tt>' Instruction</a>
3254</div>
3255
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3256<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3257
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3258<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3259
3260<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3261 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3262</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3263
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3264<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3265
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3266<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3267memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3268
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3269<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3270
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3271<p>'<tt>value</tt>' shall be a pointer value that points to a value
3272that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3273instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3274
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3275<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3276
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3277<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3278after this instruction executes. If the pointer is null, the operation
3279is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3281<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3282
3283<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3284 %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]3285 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3286</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3287</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3288
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3289<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3290<div class="doc_subsubsection">
3291 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3292</div>
3293
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3294<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3297
3298<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3299 &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]3300</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3301
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3302<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3303
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3304<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3305currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3306returns to its caller. The object is always allocated in the generic address
3307space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3308
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3309<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3310
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3311<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3312bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3313appropriate type to the program. If "NumElements" is specified, it is the
3314number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3315If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3316to be aligned to at least that boundary. If not specified, or if zero, the target
3317can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3318
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3319<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3321<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3322
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3323<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3324there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3325memory is automatically released when the function returns. The '<tt>alloca</tt>'
3326instruction is commonly used to represent automatic variables that must
3327have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3328 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]3329instructions), the memory is reclaimed. Allocating zero bytes
3330is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3331
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3332<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3333
3334<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3335 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3336 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3337 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3338 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3339</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3340</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3341
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3342<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3343<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3344Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3345<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3346<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3347<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]3348<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3349<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3350<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3351<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3352address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3353 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3354marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3355the number or order of execution of this <tt>load</tt> with other
3356volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3357instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3358<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3359The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3360(that is, the alignment of the memory address). A value of 0 or an
3361omitted "align" argument means that the operation has the preferential
3362alignment for the target. It is the responsibility of the code emitter
3363to ensure that the alignment information is correct. Overestimating
3364the alignment results in an undefined behavior. Underestimating the
3365alignment may produce less efficient code. An alignment of 1 is always
3366safe.
3367</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3368<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3369<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3370<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3371<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3372 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3373 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3374 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3375</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3376</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3377<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3378<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3379Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3380<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3381<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3382<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3383 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]3384</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3385<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3386<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3387<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3388<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3389to 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]3390operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3391of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3392operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3393optimizer is not allowed to modify the number or order of execution of
3394this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3395 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3396<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3397The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3398(that is, the alignment of the memory address). A value of 0 or an
3399omitted "align" argument means that the operation has the preferential
3400alignment for the target. It is the responsibility of the code emitter
3401to ensure that the alignment information is correct. Overestimating
3402the alignment results in an undefined behavior. Underestimating the
3403alignment may produce less efficient code. An alignment of 1 is always
3404safe.
3405</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3406<h5>Semantics:</h5>
3407<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3408at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3409<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3410<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3411 store i32 3, i32* %ptr <i>; yields {void}</i>
3412 %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]3413</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3414</div>
3415
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3416<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3417<div class="doc_subsubsection">
3418 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3419</div>
3420
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3421<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3422<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3423<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3424 &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]3425</pre>
3426
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3427<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3428
3429<p>
3430The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3431subelement of an aggregate data structure. It performs address calculation only
3432and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3433
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3434<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3435
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3436<p>The first argument is always a pointer, and forms the basis of the
3437calculation. The remaining arguments are indices, that indicate which of the
3438elements of the aggregate object are indexed. The interpretation of each index
3439is dependent on the type being indexed into. The first index always indexes the
3440pointer value given as the first argument, the second index indexes a value of
3441the type pointed to (not necessarily the value directly pointed to, since the
3442first index can be non-zero), etc. The first type indexed into must be a pointer
3443value, subsequent types can be arrays, vectors and structs. Note that subsequent
3444types being indexed into can never be pointers, since that would require loading
3445the pointer before continuing calculation.</p>
3446
3447<p>The type of each index argument depends on the type it is indexing into.
3448When indexing into a (packed) structure, only <tt>i32</tt> integer
3449<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3450only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3451will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3452
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3453<p>For example, let's consider a C code fragment and how it gets
3454compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3455
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3456<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3457<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3458struct RT {
3459 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3460 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3461 char C;
3462};
3463struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3464 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3465 double Y;
3466 struct RT Z;
3467};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3468
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3469int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3470 return &amp;s[1].Z.B[5][13];
3471}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3472</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3473</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3474
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3475<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3476
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3477<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3478<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3479%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3480%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3481
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3482define i32* %foo(%ST* %s) {
3483entry:
3484 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3485 ret i32* %reg
3486}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3487</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3488</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3489
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3490<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3491
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3492<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]3493type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3494}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3495the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3496i8 }</tt>' type, another structure. The third index indexes into the second
3497element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3498array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3499'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3500to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3501
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3502<p>Note that it is perfectly legal to index partially through a
3503structure, returning a pointer to an inner element. Because of this,
3504the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3505
3506<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3507 define i32* %foo(%ST* %s) {
3508 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3509 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3510 %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]3511 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3512 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3513 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3514 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3515</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3516
3517<p>Note that it is undefined to access an array out of bounds: array and
3518pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3519The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3520defined to be accessible as variable length arrays, which requires access
3521beyond the zero'th element.</p>
3522
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3523<p>The getelementptr instruction is often confusing. For some more insight
3524into how it works, see <a href="GetElementPtr.html">the getelementptr
3525FAQ</a>.</p>
3526
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3527<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3528
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3529<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3530 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3531 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3532 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3533 %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]3534 <i>; yields i8*:eptr</i>
3535 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3536</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3537</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3538
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3539<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3540<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3541</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3542<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3543<p>The instructions in this category are the conversion instructions (casting)
3544which all take a single operand and a type. They perform various bit conversions
3545on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3546</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3547
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3548<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3549<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3550 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3551</div>
3552<div class="doc_text">
3553
3554<h5>Syntax:</h5>
3555<pre>
3556 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3557</pre>
3558
3559<h5>Overview:</h5>
3560<p>
3561The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3562</p>
3563
3564<h5>Arguments:</h5>
3565<p>
3566The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3567be 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]3568and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3569type. The bit size of <tt>value</tt> must be larger than the bit size of
3570<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3571
3572<h5>Semantics:</h5>
3573<p>
3574The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3575and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3576larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3577It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3578
3579<h5>Example:</h5>
3580<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3581 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3582 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3583 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3584</pre>
3585</div>
3586
3587<!-- _______________________________________________________________________ -->
3588<div class="doc_subsubsection">
3589 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3590</div>
3591<div class="doc_text">
3592
3593<h5>Syntax:</h5>
3594<pre>
3595 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3596</pre>
3597
3598<h5>Overview:</h5>
3599<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3600<tt>ty2</tt>.</p>
3601
3602
3603<h5>Arguments:</h5>
3604<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]3605<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3606also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3607<tt>value</tt> must be smaller than the bit size of the destination type,
3608<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3609
3610<h5>Semantics:</h5>
3611<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]3612bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3613
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3614<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]3615
3616<h5>Example:</h5>
3617<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3618 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3619 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3620</pre>
3621</div>
3622
3623<!-- _______________________________________________________________________ -->
3624<div class="doc_subsubsection">
3625 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3626</div>
3627<div class="doc_text">
3628
3629<h5>Syntax:</h5>
3630<pre>
3631 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3632</pre>
3633
3634<h5>Overview:</h5>
3635<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3636
3637<h5>Arguments:</h5>
3638<p>
3639The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3640<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3641also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3642<tt>value</tt> must be smaller than the bit size of the destination type,
3643<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3644
3645<h5>Semantics:</h5>
3646<p>
3647The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3648bit (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]3649the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3650
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3651<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]3652
3653<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3654<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3655 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3656 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3657</pre>
3658</div>
3659
3660<!-- _______________________________________________________________________ -->
3661<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3662 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3663</div>
3664
3665<div class="doc_text">
3666
3667<h5>Syntax:</h5>
3668
3669<pre>
3670 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3671</pre>
3672
3673<h5>Overview:</h5>
3674<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3675<tt>ty2</tt>.</p>
3676
3677
3678<h5>Arguments:</h5>
3679<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3680 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3681cast it to. The size of <tt>value</tt> must be larger than the size of
3682<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3683<i>no-op cast</i>.</p>
3684
3685<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3686<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3687<a href="#t_floating">floating point</a> type to a smaller
3688<a href="#t_floating">floating point</a> type. If the value cannot fit within
3689the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3690
3691<h5>Example:</h5>
3692<pre>
3693 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3694 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3695</pre>
3696</div>
3697
3698<!-- _______________________________________________________________________ -->
3699<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3700 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3701</div>
3702<div class="doc_text">
3703
3704<h5>Syntax:</h5>
3705<pre>
3706 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3707</pre>
3708
3709<h5>Overview:</h5>
3710<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3711floating point value.</p>
3712
3713<h5>Arguments:</h5>
3714<p>The '<tt>fpext</tt>' instruction takes a
3715<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3716and a <a href="#t_floating">floating point</a> type to cast it to. The source
3717type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3718
3719<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3720<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3721<a href="#t_floating">floating point</a> type to a larger
3722<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3723used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3724<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]3725
3726<h5>Example:</h5>
3727<pre>
3728 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3729 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3730</pre>
3731</div>
3732
3733<!-- _______________________________________________________________________ -->
3734<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3735 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3736</div>
3737<div class="doc_text">
3738
3739<h5>Syntax:</h5>
3740<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3741 &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]3742</pre>
3743
3744<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3745<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3746unsigned integer equivalent of type <tt>ty2</tt>.
3747</p>
3748
3749<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3750<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]3751scalar or vector <a href="#t_floating">floating point</a> value, and a type
3752to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3753type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3754vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3755
3756<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3757<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3758<a href="#t_floating">floating point</a> operand into the nearest (rounding
3759towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3760the results are undefined.</p>
3761
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3762<h5>Example:</h5>
3763<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3764 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3765 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3766 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3767</pre>
3768</div>
3769
3770<!-- _______________________________________________________________________ -->
3771<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3772 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3773</div>
3774<div class="doc_text">
3775
3776<h5>Syntax:</h5>
3777<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3778 &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]3779</pre>
3780
3781<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3782<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3783<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]3784</p>
3785
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3786<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3787<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]3788scalar or vector <a href="#t_floating">floating point</a> value, and a type
3789to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3790type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3791vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3792
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3793<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3794<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3795<a href="#t_floating">floating point</a> operand into the nearest (rounding
3796towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3797the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3798
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3799<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3800<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3801 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3802 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3803 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3804</pre>
3805</div>
3806
3807<!-- _______________________________________________________________________ -->
3808<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3809 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3810</div>
3811<div class="doc_text">
3812
3813<h5>Syntax:</h5>
3814<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3815 &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]3816</pre>
3817
3818<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3819<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3820integer and converts that value to the <tt>ty2</tt> type.</p>
3821
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3822<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3823<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3824scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3825to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3826type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3827floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3828
3829<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3830<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3831integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3832the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3833
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3834<h5>Example:</h5>
3835<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3836 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3837 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3838</pre>
3839</div>
3840
3841<!-- _______________________________________________________________________ -->
3842<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3843 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3844</div>
3845<div class="doc_text">
3846
3847<h5>Syntax:</h5>
3848<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3849 &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]3850</pre>
3851
3852<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3853<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3854integer and converts that value to the <tt>ty2</tt> type.</p>
3855
3856<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3857<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3858scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3859to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3860type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3861floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3862
3863<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3864<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3865integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3866the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3867
3868<h5>Example:</h5>
3869<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3870 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3871 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3872</pre>
3873</div>
3874
3875<!-- _______________________________________________________________________ -->
3876<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3877 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3878</div>
3879<div class="doc_text">
3880
3881<h5>Syntax:</h5>
3882<pre>
3883 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3884</pre>
3885
3886<h5>Overview:</h5>
3887<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3888the integer type <tt>ty2</tt>.</p>
3889
3890<h5>Arguments:</h5>
3891<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3892must 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]3893<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]3894
3895<h5>Semantics:</h5>
3896<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3897<tt>ty2</tt> by interpreting the pointer value as an integer and either
3898truncating or zero extending that value to the size of the integer type. If
3899<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3900<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]3901are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3902change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3903
3904<h5>Example:</h5>
3905<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3906 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3907 %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]3908</pre>
3909</div>
3910
3911<!-- _______________________________________________________________________ -->
3912<div class="doc_subsubsection">
3913 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3914</div>
3915<div class="doc_text">
3916
3917<h5>Syntax:</h5>
3918<pre>
3919 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3920</pre>
3921
3922<h5>Overview:</h5>
3923<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3924a pointer type, <tt>ty2</tt>.</p>
3925
3926<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3927<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3928value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3929<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3930
3931<h5>Semantics:</h5>
3932<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3933<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3934the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3935size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3936the size of a pointer then a zero extension is done. If they are the same size,
3937nothing is done (<i>no-op cast</i>).</p>
3938
3939<h5>Example:</h5>
3940<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3941 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3942 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3943 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3944</pre>
3945</div>
3946
3947<!-- _______________________________________________________________________ -->
3948<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3949 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3950</div>
3951<div class="doc_text">
3952
3953<h5>Syntax:</h5>
3954<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3955 &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]3956</pre>
3957
3958<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3959
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3960<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3961<tt>ty2</tt> without changing any bits.</p>
3962
3963<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3964
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3965<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]3966a non-aggregate first class value, and a type to cast it to, which must also be
3967a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3968<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3969and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3970type is a pointer, the destination type must also be a pointer. This
3971instruction supports bitwise conversion of vectors to integers and to vectors
3972of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3973
3974<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3975<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3976<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3977this conversion. The conversion is done as if the <tt>value</tt> had been
3978stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3979converted to other pointer types with this instruction. To convert pointers to
3980other types, use the <a href="#i_inttoptr">inttoptr</a> or
3981<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3982
3983<h5>Example:</h5>
3984<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3985 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3986 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3987 %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]3988</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3989</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3990
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3991<!-- ======================================================================= -->
3992<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3993<div class="doc_text">
3994<p>The instructions in this category are the "miscellaneous"
3995instructions, which defy better classification.</p>
3996</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3997
3998<!-- _______________________________________________________________________ -->
3999<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4000</div>
4001<div class="doc_text">
4002<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4003<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]4004</pre>
4005<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4006<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4007a vector of boolean values based on comparison
4008of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4009<h5>Arguments:</h5>
4010<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4011the condition code indicating the kind of comparison to perform. It is not
4012a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4013</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4014<ol>
4015 <li><tt>eq</tt>: equal</li>
4016 <li><tt>ne</tt>: not equal </li>
4017 <li><tt>ugt</tt>: unsigned greater than</li>
4018 <li><tt>uge</tt>: unsigned greater or equal</li>
4019 <li><tt>ult</tt>: unsigned less than</li>
4020 <li><tt>ule</tt>: unsigned less or equal</li>
4021 <li><tt>sgt</tt>: signed greater than</li>
4022 <li><tt>sge</tt>: signed greater or equal</li>
4023 <li><tt>slt</tt>: signed less than</li>
4024 <li><tt>sle</tt>: signed less or equal</li>
4025</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4026<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4027<a href="#t_pointer">pointer</a>
4028or integer <a href="#t_vector">vector</a> typed.
4029They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4030<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4031<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]4032the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4033yields 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]4034</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4035<ol>
4036 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4037 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4038 </li>
4039 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4040 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4041 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4042 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4043 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4044 <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]4045 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4046 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4047 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4048 <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]4049 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4050 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4051 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4052 <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]4053 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4054 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4055 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4056 <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]4057</ol>
4058<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4059values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4060<p>If the operands are integer vectors, then they are compared
4061element by element. The result is an <tt>i1</tt> vector with
4062the same number of elements as the values being compared.
4063Otherwise, the result is an <tt>i1</tt>.
4064</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4065
4066<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4067<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4068 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4069 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4070 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4071 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4072 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4073</pre>
4074</div>
4075
4076<!-- _______________________________________________________________________ -->
4077<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4078</div>
4079<div class="doc_text">
4080<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4081<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]4082</pre>
4083<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4084<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4085or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4086of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4087<p>
4088If the operands are floating point scalars, then the result
4089type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4090</p>
4091<p>If the operands are floating point vectors, then the result type
4092is a vector of boolean with the same number of elements as the
4093operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4094<h5>Arguments:</h5>
4095<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4096the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4097a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4098<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4099 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4100 <li><tt>oeq</tt>: ordered and equal</li>
4101 <li><tt>ogt</tt>: ordered and greater than </li>
4102 <li><tt>oge</tt>: ordered and greater than or equal</li>
4103 <li><tt>olt</tt>: ordered and less than </li>
4104 <li><tt>ole</tt>: ordered and less than or equal</li>
4105 <li><tt>one</tt>: ordered and not equal</li>
4106 <li><tt>ord</tt>: ordered (no nans)</li>
4107 <li><tt>ueq</tt>: unordered or equal</li>
4108 <li><tt>ugt</tt>: unordered or greater than </li>
4109 <li><tt>uge</tt>: unordered or greater than or equal</li>
4110 <li><tt>ult</tt>: unordered or less than </li>
4111 <li><tt>ule</tt>: unordered or less than or equal</li>
4112 <li><tt>une</tt>: unordered or not equal</li>
4113 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4114 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4115</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4116<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4117<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4118<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4119either a <a href="#t_floating">floating point</a> type
4120or a <a href="#t_vector">vector</a> of floating point type.
4121They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4122<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4123<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4124according to the condition code given as <tt>cond</tt>.
4125If the operands are vectors, then the vectors are compared
4126element by element.
4127Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4128always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4129<ol>
4130 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4131 <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]4132 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4133 <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]4134 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4135 <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]4136 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4137 <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]4138 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4139 <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]4140 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4141 <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]4142 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4143 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4144 <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]4145 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4146 <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]4147 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4148 <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]4149 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4150 <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]4151 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4152 <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]4153 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4154 <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]4155 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4156 <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]4157 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4158</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4159
4160<h5>Example:</h5>
4161<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]4162 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4163 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4164 &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]4165</pre>
4166</div>
4167
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4168<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4169<div class="doc_subsubsection">
4170 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4171</div>
4172<div class="doc_text">
4173<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4174<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]4175</pre>
4176<h5>Overview:</h5>
4177<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4178element-wise comparison of its two integer vector operands.</p>
4179<h5>Arguments:</h5>
4180<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4181the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4182a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4183<ol>
4184 <li><tt>eq</tt>: equal</li>
4185 <li><tt>ne</tt>: not equal </li>
4186 <li><tt>ugt</tt>: unsigned greater than</li>
4187 <li><tt>uge</tt>: unsigned greater or equal</li>
4188 <li><tt>ult</tt>: unsigned less than</li>
4189 <li><tt>ule</tt>: unsigned less or equal</li>
4190 <li><tt>sgt</tt>: signed greater than</li>
4191 <li><tt>sge</tt>: signed greater or equal</li>
4192 <li><tt>slt</tt>: signed less than</li>
4193 <li><tt>sle</tt>: signed less or equal</li>
4194</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4195<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4196<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4197<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4198<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4199according to the condition code given as <tt>cond</tt>. The comparison yields a
4200<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4201identical type as the values being compared. The most significant bit in each
4202element is 1 if the element-wise comparison evaluates to true, and is 0
4203otherwise. All other bits of the result are undefined. The condition codes
4204are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4205instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4206
4207<h5>Example:</h5>
4208<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4209 &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>
4210 &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]4211</pre>
4212</div>
4213
4214<!-- _______________________________________________________________________ -->
4215<div class="doc_subsubsection">
4216 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4217</div>
4218<div class="doc_text">
4219<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4220<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]4221<h5>Overview:</h5>
4222<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4223element-wise comparison of its two floating point vector operands. The output
4224elements have the same width as the input elements.</p>
4225<h5>Arguments:</h5>
4226<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4227the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4228a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4229<ol>
4230 <li><tt>false</tt>: no comparison, always returns false</li>
4231 <li><tt>oeq</tt>: ordered and equal</li>
4232 <li><tt>ogt</tt>: ordered and greater than </li>
4233 <li><tt>oge</tt>: ordered and greater than or equal</li>
4234 <li><tt>olt</tt>: ordered and less than </li>
4235 <li><tt>ole</tt>: ordered and less than or equal</li>
4236 <li><tt>one</tt>: ordered and not equal</li>
4237 <li><tt>ord</tt>: ordered (no nans)</li>
4238 <li><tt>ueq</tt>: unordered or equal</li>
4239 <li><tt>ugt</tt>: unordered or greater than </li>
4240 <li><tt>uge</tt>: unordered or greater than or equal</li>
4241 <li><tt>ult</tt>: unordered or less than </li>
4242 <li><tt>ule</tt>: unordered or less than or equal</li>
4243 <li><tt>une</tt>: unordered or not equal</li>
4244 <li><tt>uno</tt>: unordered (either nans)</li>
4245 <li><tt>true</tt>: no comparison, always returns true</li>
4246</ol>
4247<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4248<a href="#t_floating">floating point</a> typed. They must also be identical
4249types.</p>
4250<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4251<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4252according to the condition code given as <tt>cond</tt>. The comparison yields a
4253<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4254an identical number of elements as the values being compared, and each element
4255having identical with to the width of the floating point elements. The most
4256significant bit in each element is 1 if the element-wise comparison evaluates to
4257true, and is 0 otherwise. All other bits of the result are undefined. The
4258condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4259<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4260
4261<h5>Example:</h5>
4262<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4263 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4264 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4265
4266 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4267 &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]4268</pre>
4269</div>
4270
4271<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4272<div class="doc_subsubsection">
4273 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4274</div>
4275
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4276<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4277
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4278<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4279
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4280<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4281<h5>Overview:</h5>
4282<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4283the SSA graph representing the function.</p>
4284<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4285
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4286<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4287field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4288as arguments, with one pair for each predecessor basic block of the
4289current block. Only values of <a href="#t_firstclass">first class</a>
4290type may be used as the value arguments to the PHI node. Only labels
4291may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4292
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4293<p>There must be no non-phi instructions between the start of a basic
4294block and the PHI instructions: i.e. PHI instructions must be first in
4295a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4296
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4297<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4298
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4299<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4300specified by the pair corresponding to the predecessor basic block that executed
4301just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4302
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4303<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4304<pre>
4305Loop: ; Infinite loop that counts from 0 on up...
4306 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4307 %nextindvar = add i32 %indvar, 1
4308 br label %Loop
4309</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4310</div>
4311
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4312<!-- _______________________________________________________________________ -->
4313<div class="doc_subsubsection">
4314 <a name="i_select">'<tt>select</tt>' Instruction</a>
4315</div>
4316
4317<div class="doc_text">
4318
4319<h5>Syntax:</h5>
4320
4321<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4322 &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>
4323
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4324 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4325</pre>
4326
4327<h5>Overview:</h5>
4328
4329<p>
4330The '<tt>select</tt>' instruction is used to choose one value based on a
4331condition, without branching.
4332</p>
4333
4334
4335<h5>Arguments:</h5>
4336
4337<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4338The '<tt>select</tt>' instruction requires an 'i1' value or
4339a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4340condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4341type. If the val1/val2 are vectors and
4342the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4343individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4344</p>
4345
4346<h5>Semantics:</h5>
4347
4348<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4349If 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]4350value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4351</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4352<p>
4353If the condition is a vector of i1, then the value arguments must
4354be vectors of the same size, and the selection is done element
4355by element.
4356</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4357
4358<h5>Example:</h5>
4359
4360<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4361 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4362</pre>
4363</div>
4364
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4365
4366<!-- _______________________________________________________________________ -->
4367<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4368 <a name="i_call">'<tt>call</tt>' Instruction</a>
4369</div>
4370
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4371<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4372
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4373<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4374<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4375 &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]4376</pre>
4377
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4378<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4380<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4381
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4382<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4383
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4384<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4385
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4386<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4387 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4388 <p>The optional "tail" marker indicates whether the callee function accesses
4389 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4390 function call is eligible for tail call optimization. Note that calls may
4391 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4392 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4393 </li>
4394 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4395 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4396 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4397 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4398 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4399
4400 <li>
4401 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4402 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4403 and '<tt>inreg</tt>' attributes are valid here.</p>
4404 </li>
4405
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4406 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4407 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4408 the type of the return value. Functions that return no value are marked
4409 <tt><a href="#t_void">void</a></tt>.</p>
4410 </li>
4411 <li>
4412 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4413 value being invoked. The argument types must match the types implied by
4414 this signature. This type can be omitted if the function is not varargs
4415 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4416 </li>
4417 <li>
4418 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4419 be invoked. In most cases, this is a direct function invocation, but
4420 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4421 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4422 </li>
4423 <li>
4424 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4425 function signature argument types. All arguments must be of
4426 <a href="#t_firstclass">first class</a> type. If the function signature
4427 indicates the function accepts a variable number of arguments, the extra
4428 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4429 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4430 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4431 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4432 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4433 '<tt>readnone</tt>' attributes are valid here.</p>
4434 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4435</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4436
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4437<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4438
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4439<p>The '<tt>call</tt>' instruction is used to cause control flow to
4440transfer to a specified function, with its incoming arguments bound to
4441the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4442instruction in the called function, control flow continues with the
4443instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4444function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4445
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4446<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4447
4448<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4449 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4450 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4451 %X = tail call i32 @foo() <i>; yields i32</i>
4452 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4453 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4454
4455 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4456 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4457 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4458 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4459 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4460 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4461</pre>
4462
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4463</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4464
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4465<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4466<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4467 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4468</div>
4469
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4470<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4471
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4472<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4473
4474<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4475 &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]4476</pre>
4477
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4478<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4479
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4480<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4481the "variable argument" area of a function call. It is used to implement the
4482<tt>va_arg</tt> macro in C.</p>
4483
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4484<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4485
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4486<p>This instruction takes a <tt>va_list*</tt> value and the type of
4487the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4488increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4489actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4490
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4491<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4492
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4493<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4494type from the specified <tt>va_list</tt> and causes the
4495<tt>va_list</tt> to point to the next argument. For more information,
4496see the variable argument handling <a href="#int_varargs">Intrinsic
4497Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4498
4499<p>It is legal for this instruction to be called in a function which does not
4500take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4501function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4502
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4503<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4504href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4505argument.</p>
4506
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4507<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4508
4509<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4510
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]4511<p>Note that the code generator does not yet fully support va_arg
4512 on many targets. Also, it does not currently support va_arg with
4513 aggregate types on any target.</p>
4514
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4515</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4516
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4517<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4518<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4519<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4520
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4521<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4522
4523<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4524well known names and semantics and are required to follow certain restrictions.
4525Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4526language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4527adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4528
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4529<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4530prefix is reserved in LLVM for intrinsic names; thus, function names may not
4531begin with this prefix. Intrinsic functions must always be external functions:
4532you cannot define the body of intrinsic functions. Intrinsic functions may
4533only be used in call or invoke instructions: it is illegal to take the address
4534of an intrinsic function. Additionally, because intrinsic functions are part
4535of the LLVM language, it is required if any are added that they be documented
4536here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4537
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4538<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4539a family of functions that perform the same operation but on different data
4540types. Because LLVM can represent over 8 million different integer types,
4541overloading is used commonly to allow an intrinsic function to operate on any
4542integer type. One or more of the argument types or the result type can be
4543overloaded to accept any integer type. Argument types may also be defined as
4544exactly matching a previous argument's type or the result type. This allows an
4545intrinsic function which accepts multiple arguments, but needs all of them to
4546be of the same type, to only be overloaded with respect to a single argument or
4547the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4548
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4549<p>Overloaded intrinsics will have the names of its overloaded argument types
4550encoded into its function name, each preceded by a period. Only those types
4551which are overloaded result in a name suffix. Arguments whose type is matched
4552against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4553take an integer of any width and returns an integer of exactly the same integer
4554width. This leads to a family of functions such as
4555<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4556Only one type, the return type, is overloaded, and only one type suffix is
4557required. Because the argument's type is matched against the return type, it
4558does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4559
4560<p>To learn how to add an intrinsic function, please see the
4561<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4562</p>
4563
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4564</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4565
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4566<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4567<div class="doc_subsection">
4568 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4569</div>
4570
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4571<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4572
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4573<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4574 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4575intrinsic functions. These functions are related to the similarly
4576named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4577
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4578<p>All of these functions operate on arguments that use a
4579target-specific value type "<tt>va_list</tt>". The LLVM assembly
4580language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4581transformations should be prepared to handle these functions regardless of
4582the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4583
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4584<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]4585instruction and the variable argument handling intrinsic functions are
4586used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4587
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4588<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4589<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4590define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4591 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4592 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4593 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4594 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4595
4596 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4597 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4598
4599 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4600 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4601 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4602 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4603 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4604
4605 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4606 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4607 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4608}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4609
4610declare void @llvm.va_start(i8*)
4611declare void @llvm.va_copy(i8*, i8*)
4612declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4613</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4614</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4615
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4616</div>
4617
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4618<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4619<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4620 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4621</div>
4622
4623
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4624<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4625<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4626<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4627<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4628<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4629<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4630href="#i_va_arg">va_arg</a></tt>.</p>
4631
4632<h5>Arguments:</h5>
4633
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4634<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]4635
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4636<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4637
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4638<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]4639macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4640<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]4641<tt>va_arg</tt> will produce the first variable argument passed to the function.
4642Unlike 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]4643last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4644
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4645</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4646
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4647<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4648<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4649 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4650</div>
4651
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4652<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4653<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4654<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4655<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4656
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4657<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4658which 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]4659or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4660
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4661<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4662
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4663<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]4664
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4665<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4666
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4667<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]4668macro available in C. In a target-dependent way, it destroys the
4669<tt>va_list</tt> element to which the argument points. Calls to <a
4670href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4671<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4672<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4673
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4674</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4675
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4676<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4677<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4678 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4679</div>
4680
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4681<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4682
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4683<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4684
4685<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4686 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4687</pre>
4688
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4689<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4690
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4691<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4692from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4693
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4694<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4695
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4696<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]4697The 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]4698
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4699
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4700<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4701
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4702<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4703macro available in C. In a target-dependent way, it copies the source
4704<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4705intrinsic is necessary because the <tt><a href="#int_va_start">
4706llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4707example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4708
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4709</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4710
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4711<!-- ======================================================================= -->
4712<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4713 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4714</div>
4715
4716<div class="doc_text">
4717
4718<p>
4719LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4720Collection</a> (GC) requires the implementation and generation of these
4721intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4722These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4723stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4724href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4725Front-ends for type-safe garbage collected languages should generate these
4726intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4727href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4728</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4729
4730<p>The garbage collection intrinsics only operate on objects in the generic
4731 address space (address space zero).</p>
4732
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4733</div>
4734
4735<!-- _______________________________________________________________________ -->
4736<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4737 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4738</div>
4739
4740<div class="doc_text">
4741
4742<h5>Syntax:</h5>
4743
4744<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4745 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4746</pre>
4747
4748<h5>Overview:</h5>
4749
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4750<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]4751the code generator, and allows some metadata to be associated with it.</p>
4752
4753<h5>Arguments:</h5>
4754
4755<p>The first argument specifies the address of a stack object that contains the
4756root pointer. The second pointer (which must be either a constant or a global
4757value address) contains the meta-data to be associated with the root.</p>
4758
4759<h5>Semantics:</h5>
4760
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4761<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]4762location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4763the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4764intrinsic may only be used in a function which <a href="#gc">specifies a GC
4765algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4766
4767</div>
4768
4769
4770<!-- _______________________________________________________________________ -->
4771<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4772 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4773</div>
4774
4775<div class="doc_text">
4776
4777<h5>Syntax:</h5>
4778
4779<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4780 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4781</pre>
4782
4783<h5>Overview:</h5>
4784
4785<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4786locations, allowing garbage collector implementations that require read
4787barriers.</p>
4788
4789<h5>Arguments:</h5>
4790
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4791<p>The second argument is the address to read from, which should be an address
4792allocated from the garbage collector. The first object is a pointer to the
4793start of the referenced object, if needed by the language runtime (otherwise
4794null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4795
4796<h5>Semantics:</h5>
4797
4798<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4799instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4800garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4801may only be used in a function which <a href="#gc">specifies a GC
4802algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4803
4804</div>
4805
4806
4807<!-- _______________________________________________________________________ -->
4808<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4809 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4810</div>
4811
4812<div class="doc_text">
4813
4814<h5>Syntax:</h5>
4815
4816<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4817 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4818</pre>
4819
4820<h5>Overview:</h5>
4821
4822<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4823locations, allowing garbage collector implementations that require write
4824barriers (such as generational or reference counting collectors).</p>
4825
4826<h5>Arguments:</h5>
4827
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4828<p>The first argument is the reference to store, the second is the start of the
4829object to store it to, and the third is the address of the field of Obj to
4830store to. If the runtime does not require a pointer to the object, Obj may be
4831null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4832
4833<h5>Semantics:</h5>
4834
4835<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4836instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4837garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4838may only be used in a function which <a href="#gc">specifies a GC
4839algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4840
4841</div>
4842
4843
4844
4845<!-- ======================================================================= -->
4846<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4847 <a name="int_codegen">Code Generator Intrinsics</a>
4848</div>
4849
4850<div class="doc_text">
4851<p>
4852These intrinsics are provided by LLVM to expose special features that may only
4853be implemented with code generator support.
4854</p>
4855
4856</div>
4857
4858<!-- _______________________________________________________________________ -->
4859<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4860 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4861</div>
4862
4863<div class="doc_text">
4864
4865<h5>Syntax:</h5>
4866<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4867 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4868</pre>
4869
4870<h5>Overview:</h5>
4871
4872<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4873The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4874target-specific value indicating the return address of the current function
4875or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4876</p>
4877
4878<h5>Arguments:</h5>
4879
4880<p>
4881The argument to this intrinsic indicates which function to return the address
4882for. Zero indicates the calling function, one indicates its caller, etc. The
4883argument is <b>required</b> to be a constant integer value.
4884</p>
4885
4886<h5>Semantics:</h5>
4887
4888<p>
4889The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4890the return address of the specified call frame, or zero if it cannot be
4891identified. The value returned by this intrinsic is likely to be incorrect or 0
4892for arguments other than zero, so it should only be used for debugging purposes.
4893</p>
4894
4895<p>
4896Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4897aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4898source-language caller.
4899</p>
4900</div>
4901
4902
4903<!-- _______________________________________________________________________ -->
4904<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4905 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4906</div>
4907
4908<div class="doc_text">
4909
4910<h5>Syntax:</h5>
4911<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4912 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4913</pre>
4914
4915<h5>Overview:</h5>
4916
4917<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4918The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4919target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4920</p>
4921
4922<h5>Arguments:</h5>
4923
4924<p>
4925The argument to this intrinsic indicates which function to return the frame
4926pointer for. Zero indicates the calling function, one indicates its caller,
4927etc. The argument is <b>required</b> to be a constant integer value.
4928</p>
4929
4930<h5>Semantics:</h5>
4931
4932<p>
4933The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4934the frame address of the specified call frame, or zero if it cannot be
4935identified. The value returned by this intrinsic is likely to be incorrect or 0
4936for arguments other than zero, so it should only be used for debugging purposes.
4937</p>
4938
4939<p>
4940Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4941aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4942source-language caller.
4943</p>
4944</div>
4945
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4946<!-- _______________________________________________________________________ -->
4947<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4948 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4949</div>
4950
4951<div class="doc_text">
4952
4953<h5>Syntax:</h5>
4954<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4955 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4956</pre>
4957
4958<h5>Overview:</h5>
4959
4960<p>
4961The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4962the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4963<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4964features like scoped automatic variable sized arrays in C99.
4965</p>
4966
4967<h5>Semantics:</h5>
4968
4969<p>
4970This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4971href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4972<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4973<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4974state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4975practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4976that were allocated after the <tt>llvm.stacksave</tt> was executed.
4977</p>
4978
4979</div>
4980
4981<!-- _______________________________________________________________________ -->
4982<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4983 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4984</div>
4985
4986<div class="doc_text">
4987
4988<h5>Syntax:</h5>
4989<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4990 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4991</pre>
4992
4993<h5>Overview:</h5>
4994
4995<p>
4996The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4997the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4998href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4999useful for implementing language features like scoped automatic variable sized
5000arrays in C99.
5001</p>
5002
5003<h5>Semantics:</h5>
5004
5005<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5006See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5007</p>
5008
5009</div>
5010
5011
5012<!-- _______________________________________________________________________ -->
5013<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5014 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5015</div>
5016
5017<div class="doc_text">
5018
5019<h5>Syntax:</h5>
5020<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5021 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]5022</pre>
5023
5024<h5>Overview:</h5>
5025
5026
5027<p>
5028The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5029a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5030no
5031effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]5032characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5033</p>
5034
5035<h5>Arguments:</h5>
5036
5037<p>
5038<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5039determining if the fetch should be for a read (0) or write (1), and
5040<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]5041locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5042<tt>locality</tt> arguments must be constant integers.
5043</p>
5044
5045<h5>Semantics:</h5>
5046
5047<p>
5048This intrinsic does not modify the behavior of the program. In particular,
5049prefetches cannot trap and do not produce a value. On targets that support this
5050intrinsic, the prefetch can provide hints to the processor cache for better
5051performance.
5052</p>
5053
5054</div>
5055
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5056<!-- _______________________________________________________________________ -->
5057<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5058 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5059</div>
5060
5061<div class="doc_text">
5062
5063<h5>Syntax:</h5>
5064<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5065 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5066</pre>
5067
5068<h5>Overview:</h5>
5069
5070
5071<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5072The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5073(PC) in a region of
5074code to simulators and other tools. The method is target specific, but it is
5075expected that the marker will use exported symbols to transmit the PC of the
5076marker.
5077The marker makes no guarantees that it will remain with any specific instruction
5078after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]5079optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5080correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5081</p>
5082
5083<h5>Arguments:</h5>
5084
5085<p>
5086<tt>id</tt> is a numerical id identifying the marker.
5087</p>
5088
5089<h5>Semantics:</h5>
5090
5091<p>
5092This intrinsic does not modify the behavior of the program. Backends that do not
5093support this intrinisic may ignore it.
5094</p>
5095
5096</div>
5097
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5098<!-- _______________________________________________________________________ -->
5099<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5100 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5101</div>
5102
5103<div class="doc_text">
5104
5105<h5>Syntax:</h5>
5106<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5107 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5108</pre>
5109
5110<h5>Overview:</h5>
5111
5112
5113<p>
5114The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5115counter register (or similar low latency, high accuracy clocks) on those targets
5116that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5117As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5118should only be used for small timings.
5119</p>
5120
5121<h5>Semantics:</h5>
5122
5123<p>
5124When directly supported, reading the cycle counter should not modify any memory.
5125Implementations are allowed to either return a application specific value or a
5126system wide value. On backends without support, this is lowered to a constant 0.
5127</p>
5128
5129</div>
5130
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5131<!-- ======================================================================= -->
5132<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5133 <a name="int_libc">Standard C Library Intrinsics</a>
5134</div>
5135
5136<div class="doc_text">
5137<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5138LLVM provides intrinsics for a few important standard C library functions.
5139These intrinsics allow source-language front-ends to pass information about the
5140alignment of the pointer arguments to the code generator, providing opportunity
5141for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5142</p>
5143
5144</div>
5145
5146<!-- _______________________________________________________________________ -->
5147<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5148 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5149</div>
5150
5151<div class="doc_text">
5152
5153<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5154<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5155width. Not all targets support all bit widths however.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5156<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5157 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5158 i8 &lt;len&gt;, i32 &lt;align&gt;)
5159 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5160 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5161 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5162 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5163 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5164 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5165</pre>
5166
5167<h5>Overview:</h5>
5168
5169<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5170The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5171location to the destination location.
5172</p>
5173
5174<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5175Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5176intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5177</p>
5178
5179<h5>Arguments:</h5>
5180
5181<p>
5182The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5183the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5184specifying the number of bytes to copy, and the fourth argument is the alignment
5185of the source and destination locations.
5186</p>
5187
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5188<p>
5189If 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]5190the caller guarantees that both the source and destination pointers are aligned
5191to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5192</p>
5193
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5194<h5>Semantics:</h5>
5195
5196<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5197The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5198location to the destination location, which are not allowed to overlap. It
5199copies "len" bytes of memory over. If the argument is known to be aligned to
5200some boundary, this can be specified as the fourth argument, otherwise it should
5201be set to 0 or 1.
5202</p>
5203</div>
5204
5205
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5206<!-- _______________________________________________________________________ -->
5207<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5208 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5209</div>
5210
5211<div class="doc_text">
5212
5213<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5214<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5215width. Not all targets support all bit widths however.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5216<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5217 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5218 i8 &lt;len&gt;, i32 &lt;align&gt;)
5219 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5220 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5221 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5222 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5223 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5224 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5225</pre>
5226
5227<h5>Overview:</h5>
5228
5229<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5230The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5231location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5232'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5233</p>
5234
5235<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5236Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5237intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5238</p>
5239
5240<h5>Arguments:</h5>
5241
5242<p>
5243The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5244the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5245specifying the number of bytes to copy, and the fourth argument is the alignment
5246of the source and destination locations.
5247</p>
5248
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5249<p>
5250If 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]5251the caller guarantees that the source and destination pointers are aligned to
5252that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5253</p>
5254
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5255<h5>Semantics:</h5>
5256
5257<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5258The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5259location to the destination location, which may overlap. It
5260copies "len" bytes of memory over. If the argument is known to be aligned to
5261some boundary, this can be specified as the fourth argument, otherwise it should
5262be set to 0 or 1.
5263</p>
5264</div>
5265
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5266
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5267<!-- _______________________________________________________________________ -->
5268<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5269 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5270</div>
5271
5272<div class="doc_text">
5273
5274<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5275<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5276width. Not all targets support all bit widths however.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5277<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5278 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5279 i8 &lt;len&gt;, i32 &lt;align&gt;)
5280 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5281 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5282 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5283 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5284 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5285 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5286</pre>
5287
5288<h5>Overview:</h5>
5289
5290<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5291The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5292byte value.
5293</p>
5294
5295<p>
5296Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5297does not return a value, and takes an extra alignment argument.
5298</p>
5299
5300<h5>Arguments:</h5>
5301
5302<p>
5303The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5304byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5305argument specifying the number of bytes to fill, and the fourth argument is the
5306known alignment of destination location.
5307</p>
5308
5309<p>
5310If 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]5311the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5312</p>
5313
5314<h5>Semantics:</h5>
5315
5316<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5317The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5318the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5319destination location. If the argument is known to be aligned to some boundary,
5320this can be specified as the fourth argument, otherwise it should be set to 0 or
53211.
5322</p>
5323</div>
5324
5325
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5326<!-- _______________________________________________________________________ -->
5327<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5328 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5329</div>
5330
5331<div class="doc_text">
5332
5333<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5334<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]5335floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5336types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5337<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5338 declare float @llvm.sqrt.f32(float %Val)
5339 declare double @llvm.sqrt.f64(double %Val)
5340 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5341 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5342 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5343</pre>
5344
5345<h5>Overview:</h5>
5346
5347<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5348The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5349returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5350<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5351negative numbers other than -0.0 (which allows for better optimization, because
5352there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5353defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5354</p>
5355
5356<h5>Arguments:</h5>
5357
5358<p>
5359The argument and return value are floating point numbers of the same type.
5360</p>
5361
5362<h5>Semantics:</h5>
5363
5364<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5365This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5366floating point number.
5367</p>
5368</div>
5369
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5370<!-- _______________________________________________________________________ -->
5371<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5372 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5373</div>
5374
5375<div class="doc_text">
5376
5377<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5378<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]5379floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5380types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5381<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5382 declare float @llvm.powi.f32(float %Val, i32 %power)
5383 declare double @llvm.powi.f64(double %Val, i32 %power)
5384 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5385 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5386 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5387</pre>
5388
5389<h5>Overview:</h5>
5390
5391<p>
5392The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5393specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5394multiplications is not defined. When a vector of floating point type is
5395used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5396</p>
5397
5398<h5>Arguments:</h5>
5399
5400<p>
5401The second argument is an integer power, and the first is a value to raise to
5402that power.
5403</p>
5404
5405<h5>Semantics:</h5>
5406
5407<p>
5408This function returns the first value raised to the second power with an
5409unspecified sequence of rounding operations.</p>
5410</div>
5411
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5412<!-- _______________________________________________________________________ -->
5413<div class="doc_subsubsection">
5414 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5415</div>
5416
5417<div class="doc_text">
5418
5419<h5>Syntax:</h5>
5420<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5421floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5422types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5423<pre>
5424 declare float @llvm.sin.f32(float %Val)
5425 declare double @llvm.sin.f64(double %Val)
5426 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5427 declare fp128 @llvm.sin.f128(fp128 %Val)
5428 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5429</pre>
5430
5431<h5>Overview:</h5>
5432
5433<p>
5434The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5435</p>
5436
5437<h5>Arguments:</h5>
5438
5439<p>
5440The argument and return value are floating point numbers of the same type.
5441</p>
5442
5443<h5>Semantics:</h5>
5444
5445<p>
5446This function returns the sine of the specified operand, returning the
5447same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5448conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5449</div>
5450
5451<!-- _______________________________________________________________________ -->
5452<div class="doc_subsubsection">
5453 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5454</div>
5455
5456<div class="doc_text">
5457
5458<h5>Syntax:</h5>
5459<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5460floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5461types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5462<pre>
5463 declare float @llvm.cos.f32(float %Val)
5464 declare double @llvm.cos.f64(double %Val)
5465 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5466 declare fp128 @llvm.cos.f128(fp128 %Val)
5467 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5468</pre>
5469
5470<h5>Overview:</h5>
5471
5472<p>
5473The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5474</p>
5475
5476<h5>Arguments:</h5>
5477
5478<p>
5479The argument and return value are floating point numbers of the same type.
5480</p>
5481
5482<h5>Semantics:</h5>
5483
5484<p>
5485This function returns the cosine of the specified operand, returning the
5486same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5487conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5488</div>
5489
5490<!-- _______________________________________________________________________ -->
5491<div class="doc_subsubsection">
5492 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5493</div>
5494
5495<div class="doc_text">
5496
5497<h5>Syntax:</h5>
5498<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5499floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5500types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5501<pre>
5502 declare float @llvm.pow.f32(float %Val, float %Power)
5503 declare double @llvm.pow.f64(double %Val, double %Power)
5504 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5505 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5506 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5507</pre>
5508
5509<h5>Overview:</h5>
5510
5511<p>
5512The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5513specified (positive or negative) power.
5514</p>
5515
5516<h5>Arguments:</h5>
5517
5518<p>
5519The second argument is a floating point power, and the first is a value to
5520raise to that power.
5521</p>
5522
5523<h5>Semantics:</h5>
5524
5525<p>
5526This function returns the first value raised to the second power,
5527returning the
5528same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5529conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5530</div>
5531
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5532
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5533<!-- ======================================================================= -->
5534<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5535 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5536</div>
5537
5538<div class="doc_text">
5539<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5540LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5541These allow efficient code generation for some algorithms.
5542</p>
5543
5544</div>
5545
5546<!-- _______________________________________________________________________ -->
5547<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5548 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5549</div>
5550
5551<div class="doc_text">
5552
5553<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5554<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5555type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5556<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5557 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5558 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5559 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5560</pre>
5561
5562<h5>Overview:</h5>
5563
5564<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5565The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5566values with an even number of bytes (positive multiple of 16 bits). These are
5567useful for performing operations on data that is not in the target's native
5568byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5569</p>
5570
5571<h5>Semantics:</h5>
5572
5573<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5574The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5575and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5576intrinsic returns an i32 value that has the four bytes of the input i32
5577swapped, 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]5578i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5579<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5580additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5581</p>
5582
5583</div>
5584
5585<!-- _______________________________________________________________________ -->
5586<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5587 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5588</div>
5589
5590<div class="doc_text">
5591
5592<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5593<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]5594width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5595<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5596 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5597 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5598 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5599 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5600 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5601</pre>
5602
5603<h5>Overview:</h5>
5604
5605<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5606The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5607value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5608</p>
5609
5610<h5>Arguments:</h5>
5611
5612<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5613The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5614integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5615</p>
5616
5617<h5>Semantics:</h5>
5618
5619<p>
5620The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5621</p>
5622</div>
5623
5624<!-- _______________________________________________________________________ -->
5625<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5626 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5627</div>
5628
5629<div class="doc_text">
5630
5631<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5632<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]5633integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5634<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5635 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5636 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5637 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5638 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5639 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5640</pre>
5641
5642<h5>Overview:</h5>
5643
5644<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5645The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5646leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5647</p>
5648
5649<h5>Arguments:</h5>
5650
5651<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5652The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5653integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5654</p>
5655
5656<h5>Semantics:</h5>
5657
5658<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5659The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5660in 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]5661of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5662</p>
5663</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5664
5665
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5666
5667<!-- _______________________________________________________________________ -->
5668<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5669 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5670</div>
5671
5672<div class="doc_text">
5673
5674<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5675<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]5676integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5677<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5678 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5679 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5680 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5681 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5682 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5683</pre>
5684
5685<h5>Overview:</h5>
5686
5687<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5688The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5689trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5690</p>
5691
5692<h5>Arguments:</h5>
5693
5694<p>
5695The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5696integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5697</p>
5698
5699<h5>Semantics:</h5>
5700
5701<p>
5702The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5703in a variable. If the src == 0 then the result is the size in bits of the type
5704of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5705</p>
5706</div>
5707
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5708<!-- _______________________________________________________________________ -->
5709<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5710 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5711</div>
5712
5713<div class="doc_text">
5714
5715<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5716<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5717on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5718<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5719 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5720 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5721</pre>
5722
5723<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5724<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5725range of bits from an integer value and returns them in the same bit width as
5726the original value.</p>
5727
5728<h5>Arguments:</h5>
5729<p>The first argument, <tt>%val</tt> and the result may be integer types of
5730any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5731arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5732
5733<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5734<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5735of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5736<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5737operates in forward mode.</p>
5738<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5739right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5740only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5741<ol>
5742 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5743 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5744 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5745 to determine the number of bits to retain.</li>
5746 <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]5747 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5748</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5749<p>In reverse mode, a similar computation is made except that the bits are
5750returned in the reverse order. So, for example, if <tt>X</tt> has the value
5751<tt>i16 0x0ACF (101011001111)</tt> and we apply
5752<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5753<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5754</div>
5755
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5756<div class="doc_subsubsection">
5757 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5758</div>
5759
5760<div class="doc_text">
5761
5762<h5>Syntax:</h5>
5763<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5764on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5765<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5766 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5767 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]5768</pre>
5769
5770<h5>Overview:</h5>
5771<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5772of bits in an integer value with another integer value. It returns the integer
5773with the replaced bits.</p>
5774
5775<h5>Arguments:</h5>
5776<p>The first argument, <tt>%val</tt> and the result may be integer types of
5777any bit width but they must have the same bit width. <tt>%val</tt> is the value
5778whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5779integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5780type since they specify only a bit index.</p>
5781
5782<h5>Semantics:</h5>
5783<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5784of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5785<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5786operates in forward mode.</p>
5787<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5788truncating it down to the size of the replacement area or zero extending it
5789up to that size.</p>
5790<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5791are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5792in <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]5793to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5794<p>In reverse mode, a similar computation is made except that the bits are
5795reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5796<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5797<h5>Examples:</h5>
5798<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5799 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5800 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5801 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5802 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5803 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5804</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5805</div>
5806
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5807<!-- ======================================================================= -->
5808<div class="doc_subsection">
5809 <a name="int_debugger">Debugger Intrinsics</a>
5810</div>
5811
5812<div class="doc_text">
5813<p>
5814The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5815are described in the <a
5816href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5817Debugging</a> document.
5818</p>
5819</div>
5820
5821
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5822<!-- ======================================================================= -->
5823<div class="doc_subsection">
5824 <a name="int_eh">Exception Handling Intrinsics</a>
5825</div>
5826
5827<div class="doc_text">
5828<p> The LLVM exception handling intrinsics (which all start with
5829<tt>llvm.eh.</tt> prefix), are described in the <a
5830href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5831Handling</a> document. </p>
5832</div>
5833
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5834<!-- ======================================================================= -->
5835<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5836 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5837</div>
5838
5839<div class="doc_text">
5840<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5841 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5842 the <tt>nest</tt> attribute, from a function. The result is a callable
5843 function pointer lacking the nest parameter - the caller does not need
5844 to provide a value for it. Instead, the value to use is stored in
5845 advance in a "trampoline", a block of memory usually allocated
5846 on the stack, which also contains code to splice the nest value into the
5847 argument list. This is used to implement the GCC nested function address
5848 extension.
5849</p>
5850<p>
5851 For example, if the function is
5852 <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]5853 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]5854<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5855 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5856 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5857 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5858 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5859</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5860 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5861 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5862</div>
5863
5864<!-- _______________________________________________________________________ -->
5865<div class="doc_subsubsection">
5866 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5867</div>
5868<div class="doc_text">
5869<h5>Syntax:</h5>
5870<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5871declare 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]5872</pre>
5873<h5>Overview:</h5>
5874<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5875 This fills the memory pointed to by <tt>tramp</tt> with code
5876 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5877</p>
5878<h5>Arguments:</h5>
5879<p>
5880 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5881 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5882 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5883 intrinsic. Note that the size and the alignment are target-specific - LLVM
5884 currently provides no portable way of determining them, so a front-end that
5885 generates this intrinsic needs to have some target-specific knowledge.
5886 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]5887</p>
5888<h5>Semantics:</h5>
5889<p>
5890 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5891 dependent code, turning it into a function. A pointer to this function is
5892 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5893 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5894 before being called. The new function's signature is the same as that of
5895 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5896 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5897 of pointer type. Calling the new function is equivalent to calling
5898 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5899 missing <tt>nest</tt> argument. If, after calling
5900 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5901 modified, then the effect of any later call to the returned function pointer is
5902 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5903</p>
5904</div>
5905
5906<!-- ======================================================================= -->
5907<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5908 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5909</div>
5910
5911<div class="doc_text">
5912<p>
5913 These intrinsic functions expand the "universal IR" of LLVM to represent
5914 hardware constructs for atomic operations and memory synchronization. This
5915 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5916 is aimed at a low enough level to allow any programming models or APIs
5917 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5918 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5919 hardware behavior. Just as hardware provides a "universal IR" for source
5920 languages, it also provides a starting point for developing a "universal"
5921 atomic operation and synchronization IR.
5922</p>
5923<p>
5924 These do <em>not</em> form an API such as high-level threading libraries,
5925 software transaction memory systems, atomic primitives, and intrinsic
5926 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5927 application libraries. The hardware interface provided by LLVM should allow
5928 a clean implementation of all of these APIs and parallel programming models.
5929 No one model or paradigm should be selected above others unless the hardware
5930 itself ubiquitously does so.
5931
5932</p>
5933</div>
5934
5935<!-- _______________________________________________________________________ -->
5936<div class="doc_subsubsection">
5937 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5938</div>
5939<div class="doc_text">
5940<h5>Syntax:</h5>
5941<pre>
5942declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5943i1 &lt;device&gt; )
5944
5945</pre>
5946<h5>Overview:</h5>
5947<p>
5948 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5949 specific pairs of memory access types.
5950</p>
5951<h5>Arguments:</h5>
5952<p>
5953 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5954 The first four arguments enables a specific barrier as listed below. The fith
5955 argument specifies that the barrier applies to io or device or uncached memory.
5956
5957</p>
5958 <ul>
5959 <li><tt>ll</tt>: load-load barrier</li>
5960 <li><tt>ls</tt>: load-store barrier</li>
5961 <li><tt>sl</tt>: store-load barrier</li>
5962 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5963 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5964 </ul>
5965<h5>Semantics:</h5>
5966<p>
5967 This intrinsic causes the system to enforce some ordering constraints upon
5968 the loads and stores of the program. This barrier does not indicate
5969 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5970 which they occur. For any of the specified pairs of load and store operations
5971 (f.ex. load-load, or store-load), all of the first operations preceding the
5972 barrier will complete before any of the second operations succeeding the
5973 barrier begin. Specifically the semantics for each pairing is as follows:
5974</p>
5975 <ul>
5976 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5977 after the barrier begins.</li>
5978
5979 <li><tt>ls</tt>: All loads before the barrier must complete before any
5980 store after the barrier begins.</li>
5981 <li><tt>ss</tt>: All stores before the barrier must complete before any
5982 store after the barrier begins.</li>
5983 <li><tt>sl</tt>: All stores before the barrier must complete before any
5984 load after the barrier begins.</li>
5985 </ul>
5986<p>
5987 These semantics are applied with a logical "and" behavior when more than one
5988 is enabled in a single memory barrier intrinsic.
5989</p>
5990<p>
5991 Backends may implement stronger barriers than those requested when they do not
5992 support as fine grained a barrier as requested. Some architectures do not
5993 need all types of barriers and on such architectures, these become noops.
5994</p>
5995<h5>Example:</h5>
5996<pre>
5997%ptr = malloc i32
5998 store i32 4, %ptr
5999
6000%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6001 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6002 <i>; guarantee the above finishes</i>
6003 store i32 8, %ptr <i>; before this begins</i>
6004</pre>
6005</div>
6006
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6007<!-- _______________________________________________________________________ -->
6008<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6009 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6010</div>
6011<div class="doc_text">
6012<h5>Syntax:</h5>
6013<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6014 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6015 any integer bit width and for different address spaces. Not all targets
6016 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6017
6018<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6019declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6020declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6021declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6022declare 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]6023
6024</pre>
6025<h5>Overview:</h5>
6026<p>
6027 This loads a value in memory and compares it to a given value. If they are
6028 equal, it stores a new value into the memory.
6029</p>
6030<h5>Arguments:</h5>
6031<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6032 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6033 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6034 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6035 this integer type. While any bit width integer may be used, targets may only
6036 lower representations they support in hardware.
6037
6038</p>
6039<h5>Semantics:</h5>
6040<p>
6041 This entire intrinsic must be executed atomically. It first loads the value
6042 in memory pointed to by <tt>ptr</tt> and compares it with the value
6043 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6044 loaded value is yielded in all cases. This provides the equivalent of an
6045 atomic compare-and-swap operation within the SSA framework.
6046</p>
6047<h5>Examples:</h5>
6048
6049<pre>
6050%ptr = malloc i32
6051 store i32 4, %ptr
6052
6053%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6054%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6055 <i>; yields {i32}:result1 = 4</i>
6056%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6057%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6058
6059%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6060%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6061 <i>; yields {i32}:result2 = 8</i>
6062%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6063
6064%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6065</pre>
6066</div>
6067
6068<!-- _______________________________________________________________________ -->
6069<div class="doc_subsubsection">
6070 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6071</div>
6072<div class="doc_text">
6073<h5>Syntax:</h5>
6074
6075<p>
6076 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6077 integer bit width. Not all targets support all bit widths however.</p>
6078<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6079declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6080declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6081declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6082declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6083
6084</pre>
6085<h5>Overview:</h5>
6086<p>
6087 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6088 the value from memory. It then stores the value in <tt>val</tt> in the memory
6089 at <tt>ptr</tt>.
6090</p>
6091<h5>Arguments:</h5>
6092
6093<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6094 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6095 <tt>val</tt> argument and the result must be integers of the same bit width.
6096 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6097 integer type. The targets may only lower integer representations they
6098 support.
6099</p>
6100<h5>Semantics:</h5>
6101<p>
6102 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6103 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6104 equivalent of an atomic swap operation within the SSA framework.
6105
6106</p>
6107<h5>Examples:</h5>
6108<pre>
6109%ptr = malloc i32
6110 store i32 4, %ptr
6111
6112%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6113%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6114 <i>; yields {i32}:result1 = 4</i>
6115%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6116%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6117
6118%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6119%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6120 <i>; yields {i32}:result2 = 8</i>
6121
6122%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6123%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6124</pre>
6125</div>
6126
6127<!-- _______________________________________________________________________ -->
6128<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6129 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6130
6131</div>
6132<div class="doc_text">
6133<h5>Syntax:</h5>
6134<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6135 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]6136 integer bit width. Not all targets support all bit widths however.</p>
6137<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6138declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6139declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6140declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6141declare 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]6142
6143</pre>
6144<h5>Overview:</h5>
6145<p>
6146 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6147 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6148</p>
6149<h5>Arguments:</h5>
6150<p>
6151
6152 The intrinsic takes two arguments, the first a pointer to an integer value
6153 and the second an integer value. The result is also an integer value. These
6154 integer types can have any bit width, but they must all have the same bit
6155 width. The targets may only lower integer representations they support.
6156</p>
6157<h5>Semantics:</h5>
6158<p>
6159 This intrinsic does a series of operations atomically. It first loads the
6160 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6161 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6162</p>
6163
6164<h5>Examples:</h5>
6165<pre>
6166%ptr = malloc i32
6167 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6168%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6169 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6170%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6171 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6172%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6173 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6174%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6175</pre>
6176</div>
6177
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6178<!-- _______________________________________________________________________ -->
6179<div class="doc_subsubsection">
6180 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6181
6182</div>
6183<div class="doc_text">
6184<h5>Syntax:</h5>
6185<p>
6186 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]6187 any integer bit width and for different address spaces. Not all targets
6188 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6189<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6190declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6191declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6192declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6193declare 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]6194
6195</pre>
6196<h5>Overview:</h5>
6197<p>
6198 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6199 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6200</p>
6201<h5>Arguments:</h5>
6202<p>
6203
6204 The intrinsic takes two arguments, the first a pointer to an integer value
6205 and the second an integer value. The result is also an integer value. These
6206 integer types can have any bit width, but they must all have the same bit
6207 width. The targets may only lower integer representations they support.
6208</p>
6209<h5>Semantics:</h5>
6210<p>
6211 This intrinsic does a series of operations atomically. It first loads the
6212 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6213 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6214</p>
6215
6216<h5>Examples:</h5>
6217<pre>
6218%ptr = malloc i32
6219 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6220%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6221 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6222%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6223 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6224%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6225 <i>; yields {i32}:result3 = 2</i>
6226%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6227</pre>
6228</div>
6229
6230<!-- _______________________________________________________________________ -->
6231<div class="doc_subsubsection">
6232 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6233 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6234 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6235 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6236
6237</div>
6238<div class="doc_text">
6239<h5>Syntax:</h5>
6240<p>
6241 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6242 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6243 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6244 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6245<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6246declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6247declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6248declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6249declare 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]6250
6251</pre>
6252
6253<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6254declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6255declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6256declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6257declare 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]6258
6259</pre>
6260
6261<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6262declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6263declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6264declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6265declare 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]6266
6267</pre>
6268
6269<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6270declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6271declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6272declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6273declare 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]6274
6275</pre>
6276<h5>Overview:</h5>
6277<p>
6278 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6279 the value stored in memory at <tt>ptr</tt>. It yields the original value
6280 at <tt>ptr</tt>.
6281</p>
6282<h5>Arguments:</h5>
6283<p>
6284
6285 These intrinsics take two arguments, the first a pointer to an integer value
6286 and the second an integer value. The result is also an integer value. These
6287 integer types can have any bit width, but they must all have the same bit
6288 width. The targets may only lower integer representations they support.
6289</p>
6290<h5>Semantics:</h5>
6291<p>
6292 These intrinsics does a series of operations atomically. They first load the
6293 value stored at <tt>ptr</tt>. They then do the bitwise operation
6294 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6295 value stored at <tt>ptr</tt>.
6296</p>
6297
6298<h5>Examples:</h5>
6299<pre>
6300%ptr = malloc i32
6301 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6302%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6303 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6304%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6305 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6306%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6307 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6308%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6309 <i>; yields {i32}:result3 = FF</i>
6310%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6311</pre>
6312</div>
6313
6314
6315<!-- _______________________________________________________________________ -->
6316<div class="doc_subsubsection">
6317 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6318 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6319 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6320 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6321
6322</div>
6323<div class="doc_text">
6324<h5>Syntax:</h5>
6325<p>
6326 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6327 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6328 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6329 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6330 support all bit widths however.</p>
6331<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6332declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6333declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6334declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6335declare 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]6336
6337</pre>
6338
6339<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6340declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6341declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6342declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6343declare 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]6344
6345</pre>
6346
6347<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6348declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6349declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6350declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6351declare 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]6352
6353</pre>
6354
6355<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6356declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6357declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6358declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6359declare 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]6360
6361</pre>
6362<h5>Overview:</h5>
6363<p>
6364 These intrinsics takes the signed or unsigned minimum or maximum of
6365 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6366 original value at <tt>ptr</tt>.
6367</p>
6368<h5>Arguments:</h5>
6369<p>
6370
6371 These intrinsics take two arguments, the first a pointer to an integer value
6372 and the second an integer value. The result is also an integer value. These
6373 integer types can have any bit width, but they must all have the same bit
6374 width. The targets may only lower integer representations they support.
6375</p>
6376<h5>Semantics:</h5>
6377<p>
6378 These intrinsics does a series of operations atomically. They first load the
6379 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6380 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6381 the original value stored at <tt>ptr</tt>.
6382</p>
6383
6384<h5>Examples:</h5>
6385<pre>
6386%ptr = malloc i32
6387 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6388%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6389 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6390%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6391 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6392%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6393 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6394%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6395 <i>; yields {i32}:result3 = 8</i>
6396%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6397</pre>
6398</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6399
6400<!-- ======================================================================= -->
6401<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6402 <a name="int_general">General Intrinsics</a>
6403</div>
6404
6405<div class="doc_text">
6406<p> This class of intrinsics is designed to be generic and has
6407no specific purpose. </p>
6408</div>
6409
6410<!-- _______________________________________________________________________ -->
6411<div class="doc_subsubsection">
6412 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6413</div>
6414
6415<div class="doc_text">
6416
6417<h5>Syntax:</h5>
6418<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6419 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]6420</pre>
6421
6422<h5>Overview:</h5>
6423
6424<p>
6425The '<tt>llvm.var.annotation</tt>' intrinsic
6426</p>
6427
6428<h5>Arguments:</h5>
6429
6430<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6431The first argument is a pointer to a value, the second is a pointer to a
6432global string, the third is a pointer to a global string which is the source
6433file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6434</p>
6435
6436<h5>Semantics:</h5>
6437
6438<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6439This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6440This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6441annotations. These have no other defined use, they are ignored by code
6442generation and optimization.
6443</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6444</div>
6445
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6446<!-- _______________________________________________________________________ -->
6447<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6448 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6449</div>
6450
6451<div class="doc_text">
6452
6453<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6454<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6455any integer bit width.
6456</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6457<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6458 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6459 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6460 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6461 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6462 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]6463</pre>
6464
6465<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6466
6467<p>
6468The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6469</p>
6470
6471<h5>Arguments:</h5>
6472
6473<p>
6474The first argument is an integer value (result of some expression),
6475the second is a pointer to a global string, the third is a pointer to a global
6476string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6477It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6478</p>
6479
6480<h5>Semantics:</h5>
6481
6482<p>
6483This intrinsic allows annotations to be put on arbitrary expressions
6484with arbitrary strings. This can be useful for special purpose optimizations
6485that want to look for these annotations. These have no other defined use, they
6486are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6487</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6488</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6489
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6490<!-- _______________________________________________________________________ -->
6491<div class="doc_subsubsection">
6492 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6493</div>
6494
6495<div class="doc_text">
6496
6497<h5>Syntax:</h5>
6498<pre>
6499 declare void @llvm.trap()
6500</pre>
6501
6502<h5>Overview:</h5>
6503
6504<p>
6505The '<tt>llvm.trap</tt>' intrinsic
6506</p>
6507
6508<h5>Arguments:</h5>
6509
6510<p>
6511None
6512</p>
6513
6514<h5>Semantics:</h5>
6515
6516<p>
6517This intrinsics is lowered to the target dependent trap instruction. If the
6518target does not have a trap instruction, this intrinsic will be lowered to the
6519call of the abort() function.
6520</p>
6521</div>
6522
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6523<!-- _______________________________________________________________________ -->
6524<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6525 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6526</div>
6527<div class="doc_text">
6528<h5>Syntax:</h5>
6529<pre>
6530declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6531
6532</pre>
6533<h5>Overview:</h5>
6534<p>
6535 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6536 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6537 it is placed on the stack before local variables.
6538</p>
6539<h5>Arguments:</h5>
6540<p>
6541 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6542 first argument is the value loaded from the stack guard
6543 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6544 has enough space to hold the value of the guard.
6545</p>
6546<h5>Semantics:</h5>
6547<p>
6548 This intrinsic causes the prologue/epilogue inserter to force the position of
6549 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6550 stack. This is to ensure that if a local variable on the stack is overwritten,
6551 it will destroy the value of the guard. When the function exits, the guard on
6552 the stack is checked against the original guard. If they're different, then
6553 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6554</p>
6555</div>
6556
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6557<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6558<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6559<address>
6560 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6561 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6562 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6563 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]6564
6565 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6566 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6567 Last modified: $Date$
6568</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6569
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6570</body>
6571</html>