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gerrit-public.fairphone.software / toolchain / llvm-project / f85850f89e924cb6c8e92c56e85f072eb8b3f038 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]29 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]30 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]31 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]32 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]33 </ol>
34 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]35 <li><a href="#typesystem">Type System</a>
36 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]38 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]39 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]40 <li><a href="#t_floating">Floating Point Types</a></li>
41 <li><a href="#t_void">Void Type</a></li>
42 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]43 </ol>
44 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]45 <li><a href="#t_derived">Derived Types</a>
46 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]47 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]48 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]49 <li><a href="#t_function">Function Type</a></li>
50 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]51 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]52 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]53 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]54 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]55 </ol>
56 </li>
57 </ol>
58 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]59 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]60 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]61 <li><a href="#simpleconstants">Simple Constants</a></li>
62 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
63 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
64 <li><a href="#undefvalues">Undefined Values</a></li>
65 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]66 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]67 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]68 <li><a href="#othervalues">Other Values</a>
69 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]70 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#instref">Instruction Reference</a>
74 <ol>
75 <li><a href="#terminators">Terminator Instructions</a>
76 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]77 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
78 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]79 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
80 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]82 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]83 </ol>
84 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]85 <li><a href="#binaryops">Binary Operations</a>
86 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]87 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
88 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
89 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]90 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
91 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
92 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]93 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
94 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
95 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]96 </ol>
97 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]98 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
99 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]100 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
101 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
102 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]103 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]104 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]106 </ol>
107 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]108 <li><a href="#vectorops">Vector Operations</a>
109 <ol>
110 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
111 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
112 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]113 </ol>
114 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]115 <li><a href="#aggregateops">Aggregate Operations</a>
116 <ol>
117 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
118 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
119 </ol>
120 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]121 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]122 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
124 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
125 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]126 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
127 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
128 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]131 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]132 <ol>
133 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
134 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]138 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
140 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
141 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]142 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
143 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]144 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]145 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]146 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#otherops">Other Operations</a>
148 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]149 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
150 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]151 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
152 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]154 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]156 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]157 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]158 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]161 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]162 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]163 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
164 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]165 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]168 </ol>
169 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]170 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
171 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]172 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]175 </ol>
176 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]177 <li><a href="#int_codegen">Code Generator Intrinsics</a>
178 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]179 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
182 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
183 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
184 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
185 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]186 </ol>
187 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]188 <li><a href="#int_libc">Standard C Library Intrinsics</a>
189 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]190 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]195 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]198 </ol>
199 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]200 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]201 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]202 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]203 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]206 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]210 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]211 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]212 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]213 <ol>
214 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]215 </ol>
216 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame^]217 <li><a href="#int_stackprotect">Stack Protector Intrinsic</a>
218 <ol>
219 <li><a href="#int_ssp">'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
220 </ol>
221 </li>
222 <li><a href="#int_atomics">Atomic intrinsics</a>
223 <ol>
224 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
225 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
226 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
227 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
228 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
229 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
230 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
231 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
232 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
233 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
234 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
235 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
236 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
237 </ol>
238 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]239 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]240 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]241 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]242 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]243 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]244 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]245 <li><a href="#int_trap">
246 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]247 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]248 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]249 </ol>
250 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]251</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]252
253<div class="doc_author">
254 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
255 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]256</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]257
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]258<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]259<div class="doc_section"> <a name="abstract">Abstract </a></div>
260<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]261
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]262<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]263<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]264LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]265type safety, low-level operations, flexibility, and the capability of
266representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]267representation used throughout all phases of the LLVM compilation
268strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]269</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]270
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]271<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]272<div class="doc_section"> <a name="introduction">Introduction</a> </div>
273<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]275<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]276
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]277<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]278different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]279representation (suitable for fast loading by a Just-In-Time compiler),
280and as a human readable assembly language representation. This allows
281LLVM to provide a powerful intermediate representation for efficient
282compiler transformations and analysis, while providing a natural means
283to debug and visualize the transformations. The three different forms
284of LLVM are all equivalent. This document describes the human readable
285representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]286
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]287<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]288while being expressive, typed, and extensible at the same time. It
289aims to be a "universal IR" of sorts, by being at a low enough level
290that high-level ideas may be cleanly mapped to it (similar to how
291microprocessors are "universal IR's", allowing many source languages to
292be mapped to them). By providing type information, LLVM can be used as
293the target of optimizations: for example, through pointer analysis, it
294can be proven that a C automatic variable is never accessed outside of
295the current function... allowing it to be promoted to a simple SSA
296value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]297
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]298</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]299
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]300<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]301<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]302
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]303<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]304
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]305<p>It is important to note that this document describes 'well formed'
306LLVM assembly language. There is a difference between what the parser
307accepts and what is considered 'well formed'. For example, the
308following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]309
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]310<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]311<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]312%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]313</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]314</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]315
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]316<p>...because the definition of <tt>%x</tt> does not dominate all of
317its uses. The LLVM infrastructure provides a verification pass that may
318be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]319automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]320the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]321by the verifier pass indicate bugs in transformation passes or input to
322the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]323</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]325<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]328<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]329<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]330
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]331<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]332
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]333 <p>LLVM identifiers come in two basic types: global and local. Global
334 identifiers (functions, global variables) begin with the @ character. Local
335 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]336 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]338<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]339 <li>Named values are represented as a string of characters with their prefix.
340 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
341 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]342 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame]343 with quotes. Special characters may be escaped using "\xx" where xx is the
344 ASCII code for the character in hexadecimal. In this way, any character can
345 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]346
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]347 <li>Unnamed values are represented as an unsigned numeric value with their
348 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]349
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]350 <li>Constants, which are described in a <a href="#constants">section about
351 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]352</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]353
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]354<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]355don't need to worry about name clashes with reserved words, and the set of
356reserved words may be expanded in the future without penalty. Additionally,
357unnamed identifiers allow a compiler to quickly come up with a temporary
358variable without having to avoid symbol table conflicts.</p>
359
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]360<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]361languages. There are keywords for different opcodes
362('<tt><a href="#i_add">add</a></tt>',
363 '<tt><a href="#i_bitcast">bitcast</a></tt>',
364 '<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]365href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]366and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]367none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]368
369<p>Here is an example of LLVM code to multiply the integer variable
370'<tt>%X</tt>' by 8:</p>
371
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]372<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]373
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]374<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]375<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]376%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]377</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]378</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]380<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]381
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]382<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]383<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]384%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]385</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]386</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]387
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]388<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]389
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]390<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]391<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]392<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
393<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
394%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]395</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]396</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]397
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]398<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
399important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]400
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]401<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]402
403 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
404 line.</li>
405
406 <li>Unnamed temporaries are created when the result of a computation is not
407 assigned to a named value.</li>
408
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]409 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]410
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]411</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]412
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]413<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]414demonstrating instructions, we will follow an instruction with a comment that
415defines the type and name of value produced. Comments are shown in italic
416text.</p>
417
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]418</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]419
420<!-- *********************************************************************** -->
421<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
422<!-- *********************************************************************** -->
423
424<!-- ======================================================================= -->
425<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
426</div>
427
428<div class="doc_text">
429
430<p>LLVM programs are composed of "Module"s, each of which is a
431translation unit of the input programs. Each module consists of
432functions, global variables, and symbol table entries. Modules may be
433combined together with the LLVM linker, which merges function (and
434global variable) definitions, resolves forward declarations, and merges
435symbol table entries. Here is an example of the "hello world" module:</p>
436
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]437<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]438<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]439<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
440 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]441
442<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]443<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]444
445<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]446define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]447 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]448 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]449 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]450
451 <i>; Call puts function to write out the string to stdout...</i>
452 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]453 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]454 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]455 href="#i_ret">ret</a> i32 0<br>}<br>
456</pre>
457</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]458
459<p>This example is made up of a <a href="#globalvars">global variable</a>
460named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
461function, and a <a href="#functionstructure">function definition</a>
462for "<tt>main</tt>".</p>
463
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464<p>In general, a module is made up of a list of global values,
465where both functions and global variables are global values. Global values are
466represented by a pointer to a memory location (in this case, a pointer to an
467array of char, and a pointer to a function), and have one of the following <a
468href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]469
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470</div>
471
472<!-- ======================================================================= -->
473<div class="doc_subsection">
474 <a name="linkage">Linkage Types</a>
475</div>
476
477<div class="doc_text">
478
479<p>
480All Global Variables and Functions have one of the following types of linkage:
481</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]482
483<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]484
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]485 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]486
487 <dd>Global values with internal linkage are only directly accessible by
488 objects in the current module. In particular, linking code into a module with
489 an internal global value may cause the internal to be renamed as necessary to
490 avoid collisions. Because the symbol is internal to the module, all
491 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]492 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]494
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]495 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]496
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]497 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
498 the same name when linkage occurs. This is typically used to implement
499 inline functions, templates, or other code which must be generated in each
500 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
501 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]503
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]504 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
505
506 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
507 linkage, except that unreferenced <tt>common</tt> globals may not be
508 discarded. This is used for globals that may be emitted in multiple
509 translation units, but that are not guaranteed to be emitted into every
510 translation unit that uses them. One example of this is tentative
511 definitions in C, such as "<tt>int X;</tt>" at global scope.
512 </dd>
513
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]514 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]515
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]516 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
517 that some targets may choose to emit different assembly sequences for them
518 for target-dependent reasons. This is used for globals that are declared
519 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]521
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]523
524 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
525 pointer to array type. When two global variables with appending linkage are
526 linked together, the two global arrays are appended together. This is the
527 LLVM, typesafe, equivalent of having the system linker append together
528 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]529 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]530
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]531 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]532 <dd>The semantics of this linkage follow the ELF object file model: the
533 symbol is weak until linked, if not linked, the symbol becomes null instead
534 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]535 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]536
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]537 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538
539 <dd>If none of the above identifiers are used, the global is externally
540 visible, meaning that it participates in linkage and can be used to resolve
541 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]542 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]543</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]544
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]545 <p>
546 The next two types of linkage are targeted for Microsoft Windows platform
547 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]548 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]549 </p>
550
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]551 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
553
554 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
555 or variable via a global pointer to a pointer that is set up by the DLL
556 exporting the symbol. On Microsoft Windows targets, the pointer name is
557 formed by combining <code>_imp__</code> and the function or variable name.
558 </dd>
559
560 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
561
562 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
563 pointer to a pointer in a DLL, so that it can be referenced with the
564 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
565 name is formed by combining <code>_imp__</code> and the function or variable
566 name.
567 </dd>
568
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]569</dl>
570
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]571<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]572variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
573variable and was linked with this one, one of the two would be renamed,
574preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
575external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]576outside of the current module.</p>
577<p>It is illegal for a function <i>declaration</i>
578to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]579or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]580<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]581linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]582</div>
583
584<!-- ======================================================================= -->
585<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]586 <a name="callingconv">Calling Conventions</a>
587</div>
588
589<div class="doc_text">
590
591<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
592and <a href="#i_invoke">invokes</a> can all have an optional calling convention
593specified for the call. The calling convention of any pair of dynamic
594caller/callee must match, or the behavior of the program is undefined. The
595following calling conventions are supported by LLVM, and more may be added in
596the future:</p>
597
598<dl>
599 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
600
601 <dd>This calling convention (the default if no other calling convention is
602 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]603 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]604 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]605 </dd>
606
607 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
608
609 <dd>This calling convention attempts to make calls as fast as possible
610 (e.g. by passing things in registers). This calling convention allows the
611 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]612 without having to conform to an externally specified ABI (Application Binary
613 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]614 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
615 supported. This calling convention does not support varargs and requires the
616 prototype of all callees to exactly match the prototype of the function
617 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]618 </dd>
619
620 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
621
622 <dd>This calling convention attempts to make code in the caller as efficient
623 as possible under the assumption that the call is not commonly executed. As
624 such, these calls often preserve all registers so that the call does not break
625 any live ranges in the caller side. This calling convention does not support
626 varargs and requires the prototype of all callees to exactly match the
627 prototype of the function definition.
628 </dd>
629
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]630 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]631
632 <dd>Any calling convention may be specified by number, allowing
633 target-specific calling conventions to be used. Target specific calling
634 conventions start at 64.
635 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]636</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]637
638<p>More calling conventions can be added/defined on an as-needed basis, to
639support pascal conventions or any other well-known target-independent
640convention.</p>
641
642</div>
643
644<!-- ======================================================================= -->
645<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]646 <a name="visibility">Visibility Styles</a>
647</div>
648
649<div class="doc_text">
650
651<p>
652All Global Variables and Functions have one of the following visibility styles:
653</p>
654
655<dl>
656 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
657
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]658 <dd>On targets that use the ELF object file format, default visibility means
659 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]660 modules and, in shared libraries, means that the declared entity may be
661 overridden. On Darwin, default visibility means that the declaration is
662 visible to other modules. Default visibility corresponds to "external
663 linkage" in the language.
664 </dd>
665
666 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
667
668 <dd>Two declarations of an object with hidden visibility refer to the same
669 object if they are in the same shared object. Usually, hidden visibility
670 indicates that the symbol will not be placed into the dynamic symbol table,
671 so no other module (executable or shared library) can reference it
672 directly.
673 </dd>
674
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]675 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
676
677 <dd>On ELF, protected visibility indicates that the symbol will be placed in
678 the dynamic symbol table, but that references within the defining module will
679 bind to the local symbol. That is, the symbol cannot be overridden by another
680 module.
681 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]682</dl>
683
684</div>
685
686<!-- ======================================================================= -->
687<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]688 <a name="globalvars">Global Variables</a>
689</div>
690
691<div class="doc_text">
692
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]693<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]694instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]695an explicit section to be placed in, and may have an optional explicit alignment
696specified. A variable may be defined as "thread_local", which means that it
697will not be shared by threads (each thread will have a separated copy of the
698variable). A variable may be defined as a global "constant," which indicates
699that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]700optimization, allowing the global data to be placed in the read-only section of
701an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]702cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]703
704<p>
705LLVM explicitly allows <em>declarations</em> of global variables to be marked
706constant, even if the final definition of the global is not. This capability
707can be used to enable slightly better optimization of the program, but requires
708the language definition to guarantee that optimizations based on the
709'constantness' are valid for the translation units that do not include the
710definition.
711</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]712
713<p>As SSA values, global variables define pointer values that are in
714scope (i.e. they dominate) all basic blocks in the program. Global
715variables always define a pointer to their "content" type because they
716describe a region of memory, and all memory objects in LLVM are
717accessed through pointers.</p>
718
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]719<p>A global variable may be declared to reside in a target-specifc numbered
720address space. For targets that support them, address spaces may affect how
721optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]722the variable. The default address space is zero. The address space qualifier
723must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]724
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]725<p>LLVM allows an explicit section to be specified for globals. If the target
726supports it, it will emit globals to the section specified.</p>
727
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]728<p>An explicit alignment may be specified for a global. If not present, or if
729the alignment is set to zero, the alignment of the global is set by the target
730to whatever it feels convenient. If an explicit alignment is specified, the
731global is forced to have at least that much alignment. All alignments must be
732a power of 2.</p>
733
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]734<p>For example, the following defines a global in a numbered address space with
735an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]736
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]737<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]738<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]739@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]740</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]741</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]742
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]743</div>
744
745
746<!-- ======================================================================= -->
747<div class="doc_subsection">
748 <a name="functionstructure">Functions</a>
749</div>
750
751<div class="doc_text">
752
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]753<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
754an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]755<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]756<a href="#callingconv">calling convention</a>, a return type, an optional
757<a href="#paramattrs">parameter attribute</a> for the return type, a function
758name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]759<a href="#paramattrs">parameter attributes</a>), optional
760<a href="#fnattrs">function attributes</a>, an optional section,
761an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]762an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763
764LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
765optional <a href="#linkage">linkage type</a>, an optional
766<a href="#visibility">visibility style</a>, an optional
767<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]768<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]769name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]770<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]771
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]772<p>A function definition contains a list of basic blocks, forming the CFG
773(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]774the function. Each basic block may optionally start with a label (giving the
775basic block a symbol table entry), contains a list of instructions, and ends
776with a <a href="#terminators">terminator</a> instruction (such as a branch or
777function return).</p>
778
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]779<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]780executed on entrance to the function, and it is not allowed to have predecessor
781basic blocks (i.e. there can not be any branches to the entry block of a
782function). Because the block can have no predecessors, it also cannot have any
783<a href="#i_phi">PHI nodes</a>.</p>
784
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]785<p>LLVM allows an explicit section to be specified for functions. If the target
786supports it, it will emit functions to the section specified.</p>
787
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]788<p>An explicit alignment may be specified for a function. If not present, or if
789the alignment is set to zero, the alignment of the function is set by the target
790to whatever it feels convenient. If an explicit alignment is specified, the
791function is forced to have at least that much alignment. All alignments must be
792a power of 2.</p>
793
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]794 <h5>Syntax:</h5>
795
796<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]797<tt>
798define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
799 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
800 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
801 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
802 [<a href="#gc">gc</a>] { ... }
803</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]804</div>
805
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]806</div>
807
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]808
809<!-- ======================================================================= -->
810<div class="doc_subsection">
811 <a name="aliasstructure">Aliases</a>
812</div>
813<div class="doc_text">
814 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]815 function, global variable, another alias or bitcast of global value). Aliases
816 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]817 optional <a href="#visibility">visibility style</a>.</p>
818
819 <h5>Syntax:</h5>
820
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]821<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]822<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]823@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]824</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]825</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]826
827</div>
828
829
830
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]831<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]832<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
833<div class="doc_text">
834 <p>The return type and each parameter of a function type may have a set of
835 <i>parameter attributes</i> associated with them. Parameter attributes are
836 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]837 a function. Parameter attributes are considered to be part of the function,
838 not of the function type, so functions with different parameter attributes
839 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]840
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]841 <p>Parameter attributes are simple keywords that follow the type specified. If
842 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]843 example:</p>
844
845<div class="doc_code">
846<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]847declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]848declare i32 @atoi(i8 zeroext)
849declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]850</pre>
851</div>
852
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]853 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
854 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]855
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]856 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]857 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]858 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]859 <dd>This indicates to the code generator that the parameter or return value
860 should be zero-extended to a 32-bit value by the caller (for a parameter)
861 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]862
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]863 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]864 <dd>This indicates to the code generator that the parameter or return value
865 should be sign-extended to a 32-bit value by the caller (for a parameter)
866 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]867
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]868 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]869 <dd>This indicates that this parameter or return value should be treated
870 in a special target-dependent fashion during while emitting code for a
871 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]872 to memory, though some targets use it to distinguish between two different
873 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]874
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]875 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]876 <dd>This indicates that the pointer parameter should really be passed by
877 value to the function. The attribute implies that a hidden copy of the
878 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]879 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]880 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]881 value, but is also valid on pointers to scalars. The copy is considered to
882 belong to the caller not the callee (for example,
883 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]884 <tt>byval</tt> parameters). This is not a valid attribute for return
885 values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]886
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]887 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]888 <dd>This indicates that the pointer parameter specifies the address of a
889 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]890 This pointer must be guaranteed by the caller to be valid: loads and stores
891 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]892 be applied to the first parameter. This is not a valid attribute for
893 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]894
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]895 <dt><tt>noalias</tt></dt>
Owen Anderson61101282008-02-18 04:09:01 +0000[diff] [blame]896 <dd>This indicates that the parameter does not alias any global or any other
897 parameter. The caller is responsible for ensuring that this is the case,
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]898 usually by placing the value in a stack allocation. This is not a valid
899 attribute for return values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]900
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]901 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]902 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]903 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
904 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]905 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]906
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]907</div>
908
909<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]910<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]911 <a name="gc">Garbage Collector Names</a>
912</div>
913
914<div class="doc_text">
915<p>Each function may specify a garbage collector name, which is simply a
916string.</p>
917
918<div class="doc_code"><pre
919>define void @f() gc "name" { ...</pre></div>
920
921<p>The compiler declares the supported values of <i>name</i>. Specifying a
922collector which will cause the compiler to alter its output in order to support
923the named garbage collection algorithm.</p>
924</div>
925
926<!-- ======================================================================= -->
927<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]928 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]929</div>
930
931<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]932
933<p>Function attributes are set to communicate additional information about
934 a function. Function attributes are considered to be part of the function,
935 not of the function type, so functions with different parameter attributes
936 can have the same function type.</p>
937
938 <p>Function attributes are simple keywords that follow the type specified. If
939 multiple attributes are needed, they are space separated. For
940 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]941
942<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]943<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]944define void @f() noinline { ... }
945define void @f() alwaysinline { ... }
946define void @f() alwaysinline optsize { ... }
947define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]948</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]949</div>
950
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]951<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]952<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]953<dd>This attribute indicates that the inliner should attempt to inline this
954function into callers whenever possible, ignoring any active inlining size
955threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]956
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]957<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]958<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]959in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]960<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]961
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]962<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]963<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]964make choices that keep the code size of this function low, and otherwise do
965optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]966
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]967<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]968<dd>This function attribute indicates that the function never returns normally.
969This produces undefined behavior at runtime if the function ever does
970dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]971
972<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]973<dd>This function attribute indicates that the function never returns with an
974unwind or exceptional control flow. If the function does unwind, its runtime
975behavior is undefined.</dd>
976
977<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]978<dd>This attribute indicates that the function computes its result (or the
979exception it throws) based strictly on its arguments, without dereferencing any
980pointer arguments or otherwise accessing any mutable state (e.g. memory, control
981registers, etc) visible to caller functions. It does not write through any
982pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
983never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]984
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]985<dt><tt><a name="readonly">readonly</a></tt></dt>
986<dd>This attribute indicates that the function does not write through any
987pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
988or otherwise modify any state (e.g. memory, control registers, etc) visible to
989caller functions. It may dereference pointer arguments and read state that may
990be set in the caller. A readonly function always returns the same value (or
991throws the same exception) when called with the same set of arguments and global
992state.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]993
994<dt><tt><a name="ssp">ssp</a></tt></dt>
995<dd>This attribute indicates that the function should emit a stack smashing
996protector. It is in the form of a "canary"&mdash;a random value placed on the
997stack before the local variables that's checked upon return from the function to
998see if it has been overwritten. A heuristic is used to determine if a function
999needs stack protectors or not.</dd>
1000
1001<dt><tt>ssp-req</tt></dt>
1002<dd>This attribute indicates that the function should <em>always</em> emit a
1003stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
1004function attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1005</dl>
1006
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1007</div>
1008
1009<!-- ======================================================================= -->
1010<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1011 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1012</div>
1013
1014<div class="doc_text">
1015<p>
1016Modules may contain "module-level inline asm" blocks, which corresponds to the
1017GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1018LLVM and treated as a single unit, but may be separated in the .ll file if
1019desired. The syntax is very simple:
1020</p>
1021
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1022<div class="doc_code">
1023<pre>
1024module asm "inline asm code goes here"
1025module asm "more can go here"
1026</pre>
1027</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1028
1029<p>The strings can contain any character by escaping non-printable characters.
1030 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1031 for the number.
1032</p>
1033
1034<p>
1035 The inline asm code is simply printed to the machine code .s file when
1036 assembly code is generated.
1037</p>
1038</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1039
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1040<!-- ======================================================================= -->
1041<div class="doc_subsection">
1042 <a name="datalayout">Data Layout</a>
1043</div>
1044
1045<div class="doc_text">
1046<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1047data is to be laid out in memory. The syntax for the data layout is simply:</p>
1048<pre> target datalayout = "<i>layout specification</i>"</pre>
1049<p>The <i>layout specification</i> consists of a list of specifications
1050separated by the minus sign character ('-'). Each specification starts with a
1051letter and may include other information after the letter to define some
1052aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1053<dl>
1054 <dt><tt>E</tt></dt>
1055 <dd>Specifies that the target lays out data in big-endian form. That is, the
1056 bits with the most significance have the lowest address location.</dd>
1057 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1058 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1059 the bits with the least significance have the lowest address location.</dd>
1060 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1061 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1062 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1063 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1064 too.</dd>
1065 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1066 <dd>This specifies the alignment for an integer type of a given bit
1067 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1068 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1069 <dd>This specifies the alignment for a vector type of a given bit
1070 <i>size</i>.</dd>
1071 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1072 <dd>This specifies the alignment for a floating point type of a given bit
1073 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1074 (double).</dd>
1075 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1076 <dd>This specifies the alignment for an aggregate type of a given bit
1077 <i>size</i>.</dd>
1078</dl>
1079<p>When constructing the data layout for a given target, LLVM starts with a
1080default set of specifications which are then (possibly) overriden by the
1081specifications in the <tt>datalayout</tt> keyword. The default specifications
1082are given in this list:</p>
1083<ul>
1084 <li><tt>E</tt> - big endian</li>
1085 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1086 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1087 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1088 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1089 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1090 <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]1091 alignment of 64-bits</li>
1092 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1093 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1094 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1095 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1096 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1097</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1098<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1099following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1100<ol>
1101 <li>If the type sought is an exact match for one of the specifications, that
1102 specification is used.</li>
1103 <li>If no match is found, and the type sought is an integer type, then the
1104 smallest integer type that is larger than the bitwidth of the sought type is
1105 used. If none of the specifications are larger than the bitwidth then the the
1106 largest integer type is used. For example, given the default specifications
1107 above, the i7 type will use the alignment of i8 (next largest) while both
1108 i65 and i256 will use the alignment of i64 (largest specified).</li>
1109 <li>If no match is found, and the type sought is a vector type, then the
1110 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1111 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1112 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1113</ol>
1114</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1115
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1116<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1117<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1118<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1119
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1120<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1121
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1122<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1123intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1124optimizations to be performed on the intermediate representation directly,
1125without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1126extra analyses on the side before the transformation. A strong type
1127system makes it easier to read the generated code and enables novel
1128analyses and transformations that are not feasible to perform on normal
1129three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1130
1131</div>
1132
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1133<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1134<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1135Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1136<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1137<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1138classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1139
1140<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1141 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1142 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1143 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1144 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1145 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1146 </tr>
1147 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1148 <td><a href="#t_floating">floating point</a></td>
1149 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1150 </tr>
1151 <tr>
1152 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1153 <td><a href="#t_integer">integer</a>,
1154 <a href="#t_floating">floating point</a>,
1155 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1156 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1157 <a href="#t_struct">structure</a>,
1158 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1159 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1160 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1161 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1162 <tr>
1163 <td><a href="#t_primitive">primitive</a></td>
1164 <td><a href="#t_label">label</a>,
1165 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1166 <a href="#t_floating">floating point</a>.</td>
1167 </tr>
1168 <tr>
1169 <td><a href="#t_derived">derived</a></td>
1170 <td><a href="#t_integer">integer</a>,
1171 <a href="#t_array">array</a>,
1172 <a href="#t_function">function</a>,
1173 <a href="#t_pointer">pointer</a>,
1174 <a href="#t_struct">structure</a>,
1175 <a href="#t_pstruct">packed structure</a>,
1176 <a href="#t_vector">vector</a>,
1177 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1178 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1179 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1180 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1181</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1182
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1183<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1184most important. Values of these types are the only ones which can be
1185produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1186instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1187</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1188
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1189<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1190<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1191
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1192<div class="doc_text">
1193<p>The primitive types are the fundamental building blocks of the LLVM
1194system.</p>
1195
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1196</div>
1197
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1198<!-- _______________________________________________________________________ -->
1199<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1200
1201<div class="doc_text">
1202 <table>
1203 <tbody>
1204 <tr><th>Type</th><th>Description</th></tr>
1205 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1206 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1207 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1208 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1209 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1210 </tbody>
1211 </table>
1212</div>
1213
1214<!-- _______________________________________________________________________ -->
1215<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1216
1217<div class="doc_text">
1218<h5>Overview:</h5>
1219<p>The void type does not represent any value and has no size.</p>
1220
1221<h5>Syntax:</h5>
1222
1223<pre>
1224 void
1225</pre>
1226</div>
1227
1228<!-- _______________________________________________________________________ -->
1229<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1230
1231<div class="doc_text">
1232<h5>Overview:</h5>
1233<p>The label type represents code labels.</p>
1234
1235<h5>Syntax:</h5>
1236
1237<pre>
1238 label
1239</pre>
1240</div>
1241
1242
1243<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1244<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1245
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1246<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1247
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1248<p>The real power in LLVM comes from the derived types in the system.
1249This is what allows a programmer to represent arrays, functions,
1250pointers, and other useful types. Note that these derived types may be
1251recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1252
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1253</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1255<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1256<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1257
1258<div class="doc_text">
1259
1260<h5>Overview:</h5>
1261<p>The integer type is a very simple derived type that simply specifies an
1262arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12632^23-1 (about 8 million) can be specified.</p>
1264
1265<h5>Syntax:</h5>
1266
1267<pre>
1268 iN
1269</pre>
1270
1271<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1272value.</p>
1273
1274<h5>Examples:</h5>
1275<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1276 <tbody>
1277 <tr>
1278 <td><tt>i1</tt></td>
1279 <td>a single-bit integer.</td>
1280 </tr><tr>
1281 <td><tt>i32</tt></td>
1282 <td>a 32-bit integer.</td>
1283 </tr><tr>
1284 <td><tt>i1942652</tt></td>
1285 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1286 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1287 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1288</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1289</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1290
1291<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1292<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1293
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1294<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1296<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1297
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1298<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1299sequentially in memory. The array type requires a size (number of
1300elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1301
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1302<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1303
1304<pre>
1305 [&lt;# elements&gt; x &lt;elementtype&gt;]
1306</pre>
1307
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1308<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1309be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1310
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1311<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1312<table class="layout">
1313 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1314 <td class="left"><tt>[40 x i32]</tt></td>
1315 <td class="left">Array of 40 32-bit integer values.</td>
1316 </tr>
1317 <tr class="layout">
1318 <td class="left"><tt>[41 x i32]</tt></td>
1319 <td class="left">Array of 41 32-bit integer values.</td>
1320 </tr>
1321 <tr class="layout">
1322 <td class="left"><tt>[4 x i8]</tt></td>
1323 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1324 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1325</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1326<p>Here are some examples of multidimensional arrays:</p>
1327<table class="layout">
1328 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1329 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1330 <td class="left">3x4 array of 32-bit integer values.</td>
1331 </tr>
1332 <tr class="layout">
1333 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1334 <td class="left">12x10 array of single precision floating point values.</td>
1335 </tr>
1336 <tr class="layout">
1337 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1338 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1339 </tr>
1340</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1341
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1342<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1343length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1344LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1345As a special case, however, zero length arrays are recognized to be variable
1346length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1347type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1348
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1349</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1350
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1351<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1352<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1353<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1354
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1355<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1356
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1357<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1358consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1359return 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]1360If 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]1361class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1363<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1364
1365<pre>
1366 &lt;returntype list&gt; (&lt;parameter list&gt;)
1367</pre>
1368
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1369<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]1370specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1371which indicates that the function takes a variable number of arguments.
1372Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1373 href="#int_varargs">variable argument handling intrinsic</a> functions.
1374'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1375<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1376
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1377<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1378<table class="layout">
1379 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1380 <td class="left"><tt>i32 (i32)</tt></td>
1381 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1382 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1383 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1384 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1385 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1386 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1387 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1388 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1389 <tt>float</tt>.
1390 </td>
1391 </tr><tr class="layout">
1392 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1393 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1394 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1395 which returns an integer. This is the signature for <tt>printf</tt> in
1396 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1397 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1398 </tr><tr class="layout">
1399 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel8dec6c22008-03-24 18:10:52 +0000[diff] [blame]1400 <td class="left">A function taking an <tt>i32></tt>, returning two
1401 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1402 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1403 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1404</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1406</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1407<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1408<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1409<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1410<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1411<p>The structure type is used to represent a collection of data members
1412together in memory. The packing of the field types is defined to match
1413the ABI of the underlying processor. The elements of a structure may
1414be any type that has a size.</p>
1415<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1416and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1417field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1418instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1419<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1420<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1421<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1422<table class="layout">
1423 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1424 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1425 <td class="left">A triple of three <tt>i32</tt> values</td>
1426 </tr><tr class="layout">
1427 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1428 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1429 second element is a <a href="#t_pointer">pointer</a> to a
1430 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1431 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1432 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1433</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1434</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1435
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1436<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1437<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1438</div>
1439<div class="doc_text">
1440<h5>Overview:</h5>
1441<p>The packed structure type is used to represent a collection of data members
1442together in memory. There is no padding between fields. Further, the alignment
1443of a packed structure is 1 byte. The elements of a packed structure may
1444be any type that has a size.</p>
1445<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1446and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1447field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1448instruction.</p>
1449<h5>Syntax:</h5>
1450<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1451<h5>Examples:</h5>
1452<table class="layout">
1453 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1454 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1455 <td class="left">A triple of three <tt>i32</tt> values</td>
1456 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1457 <td class="left">
1458<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1459 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1460 second element is a <a href="#t_pointer">pointer</a> to a
1461 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1462 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1463 </tr>
1464</table>
1465</div>
1466
1467<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1468<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1469<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1470<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1471<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1472reference to another object, which must live in memory. Pointer types may have
1473an optional address space attribute defining the target-specific numbered
1474address space where the pointed-to object resides. The default address space is
1475zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1476<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1477<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1478<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1479<table class="layout">
1480 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1481 <td class="left"><tt>[4x i32]*</tt></td>
1482 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1483 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1484 </tr>
1485 <tr class="layout">
1486 <td class="left"><tt>i32 (i32 *) *</tt></td>
1487 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1488 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1489 <tt>i32</tt>.</td>
1490 </tr>
1491 <tr class="layout">
1492 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1493 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1494 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1495 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1496</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1497</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1498
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1499<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1500<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1501<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1502
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1503<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1504
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1505<p>A vector type is a simple derived type that represents a vector
1506of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1507are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1508A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1509elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1510of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1511considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1512
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1513<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1514
1515<pre>
1516 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1517</pre>
1518
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1519<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1520be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1521
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1522<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1523
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1524<table class="layout">
1525 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1526 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1527 <td class="left">Vector of 4 32-bit integer values.</td>
1528 </tr>
1529 <tr class="layout">
1530 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1531 <td class="left">Vector of 8 32-bit floating-point values.</td>
1532 </tr>
1533 <tr class="layout">
1534 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1535 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1536 </tr>
1537</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1538</div>
1539
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1540<!-- _______________________________________________________________________ -->
1541<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1542<div class="doc_text">
1543
1544<h5>Overview:</h5>
1545
1546<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1547corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1548In LLVM, opaque types can eventually be resolved to any type (not just a
1549structure type).</p>
1550
1551<h5>Syntax:</h5>
1552
1553<pre>
1554 opaque
1555</pre>
1556
1557<h5>Examples:</h5>
1558
1559<table class="layout">
1560 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1561 <td class="left"><tt>opaque</tt></td>
1562 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1563 </tr>
1564</table>
1565</div>
1566
1567
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1568<!-- *********************************************************************** -->
1569<div class="doc_section"> <a name="constants">Constants</a> </div>
1570<!-- *********************************************************************** -->
1571
1572<div class="doc_text">
1573
1574<p>LLVM has several different basic types of constants. This section describes
1575them all and their syntax.</p>
1576
1577</div>
1578
1579<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1580<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1581
1582<div class="doc_text">
1583
1584<dl>
1585 <dt><b>Boolean constants</b></dt>
1586
1587 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1588 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1589 </dd>
1590
1591 <dt><b>Integer constants</b></dt>
1592
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1593 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1594 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1595 integer types.
1596 </dd>
1597
1598 <dt><b>Floating point constants</b></dt>
1599
1600 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1601 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1602 notation (see below). The assembler requires the exact decimal value of
1603 a floating-point constant. For example, the assembler accepts 1.25 but
1604 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1605 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1606
1607 <dt><b>Null pointer constants</b></dt>
1608
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1609 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1610 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1611
1612</dl>
1613
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1614<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1615of floating point constants. For example, the form '<tt>double
16160x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16174.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1618(and the only time that they are generated by the disassembler) is when a
1619floating point constant must be emitted but it cannot be represented as a
1620decimal floating point number. For example, NaN's, infinities, and other
1621special values are represented in their IEEE hexadecimal format so that
1622assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1623
1624</div>
1625
1626<!-- ======================================================================= -->
1627<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1628</div>
1629
1630<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1631<p>Aggregate constants arise from aggregation of simple constants
1632and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1633
1634<dl>
1635 <dt><b>Structure constants</b></dt>
1636
1637 <dd>Structure constants are represented with notation similar to structure
1638 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1639 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1640 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]1641 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1642 types of elements must match those specified by the type.
1643 </dd>
1644
1645 <dt><b>Array constants</b></dt>
1646
1647 <dd>Array constants are represented with notation similar to array type
1648 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1649 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1650 constants must have <a href="#t_array">array type</a>, and the number and
1651 types of elements must match those specified by the type.
1652 </dd>
1653
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1654 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1655
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1656 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1657 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1658 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]1659 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1660 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1661 match those specified by the type.
1662 </dd>
1663
1664 <dt><b>Zero initialization</b></dt>
1665
1666 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1667 value to zero of <em>any</em> type, including scalar and aggregate types.
1668 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]1669 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1670 initializers.
1671 </dd>
1672</dl>
1673
1674</div>
1675
1676<!-- ======================================================================= -->
1677<div class="doc_subsection">
1678 <a name="globalconstants">Global Variable and Function Addresses</a>
1679</div>
1680
1681<div class="doc_text">
1682
1683<p>The addresses of <a href="#globalvars">global variables</a> and <a
1684href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1685constants. These constants are explicitly referenced when the <a
1686href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1687href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1688file:</p>
1689
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1690<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1691<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1692@X = global i32 17
1693@Y = global i32 42
1694@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1695</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1696</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1697
1698</div>
1699
1700<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1701<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1702<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1703 <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]1704 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1705 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1706
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1707 <p>Undefined values indicate to the compiler that the program is well defined
1708 no matter what value is used, giving the compiler more freedom to optimize.
1709 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1710</div>
1711
1712<!-- ======================================================================= -->
1713<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1714</div>
1715
1716<div class="doc_text">
1717
1718<p>Constant expressions are used to allow expressions involving other constants
1719to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1720href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1721that does not have side effects (e.g. load and call are not supported). The
1722following is the syntax for constant expressions:</p>
1723
1724<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1725 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1726 <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]1727 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1728
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1729 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1730 <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]1731 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]1732
1733 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1734 <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]1735 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]1736
1737 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1738 <dd>Truncate a floating point constant to another floating point type. The
1739 size of CST must be larger than the size of TYPE. Both types must be
1740 floating point.</dd>
1741
1742 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1743 <dd>Floating point extend a constant to another type. The size of CST must be
1744 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1745
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1746 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1747 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1748 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1749 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1750 of the same number of elements. If the value won't fit in the integer type,
1751 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1752
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1753 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1754 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1755 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1756 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1757 of the same number of elements. If the value won't fit in the integer type,
1758 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1759
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1760 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1761 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1762 constant. TYPE must be a scalar or vector floating point type. CST must be of
1763 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1764 of the same number of elements. If the value won't fit in the floating point
1765 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1766
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1767 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1768 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1769 constant. TYPE must be a scalar or vector floating point type. CST must be of
1770 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1771 of the same number of elements. If the value won't fit in the floating point
1772 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1773
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1774 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1775 <dd>Convert a pointer typed constant to the corresponding integer constant
1776 TYPE must be an integer type. CST must be of pointer type. The CST value is
1777 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1778
1779 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1780 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1781 pointer type. CST must be of integer type. The CST value is zero extended,
1782 truncated, or unchanged to make it fit in a pointer size. This one is
1783 <i>really</i> dangerous!</dd>
1784
1785 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1786 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1787 identical (same number of bits). The conversion is done as if the CST value
1788 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]1789 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1790 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]1791 pointers it is only valid to cast to another pointer type. It is not valid
1792 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1793 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1794
1795 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1796
1797 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1798 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1799 instruction, the index list may have zero or more indexes, which are required
1800 to make sense for the type of "CSTPTR".</dd>
1801
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1802 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1803
1804 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1805 constants.</dd>
1806
1807 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1808 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1809
1810 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1811 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1812
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1813 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1814 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1815
1816 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1817 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1818
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1819 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1820
1821 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1822 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1823
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1824 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1825
1826 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1827 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1828
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1829
1830 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1831
1832 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1833 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1834
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1835 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1836
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1837 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1838 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1839 binary</a> operations. The constraints on operands are the same as those for
1840 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1841 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1842</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1843</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1844
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1845<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1846<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1847<!-- *********************************************************************** -->
1848
1849<!-- ======================================================================= -->
1850<div class="doc_subsection">
1851<a name="inlineasm">Inline Assembler Expressions</a>
1852</div>
1853
1854<div class="doc_text">
1855
1856<p>
1857LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1858Module-Level Inline Assembly</a>) through the use of a special value. This
1859value represents the inline assembler as a string (containing the instructions
1860to emit), a list of operand constraints (stored as a string), and a flag that
1861indicates whether or not the inline asm expression has side effects. An example
1862inline assembler expression is:
1863</p>
1864
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1865<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1866<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1867i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1868</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1869</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1870
1871<p>
1872Inline assembler expressions may <b>only</b> be used as the callee operand of
1873a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1874</p>
1875
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1876<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1877<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1878%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]1879</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1880</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1881
1882<p>
1883Inline asms with side effects not visible in the constraint list must be marked
1884as having side effects. This is done through the use of the
1885'<tt>sideeffect</tt>' keyword, like so:
1886</p>
1887
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1888<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1889<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1890call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1891</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1892</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1893
1894<p>TODO: The format of the asm and constraints string still need to be
1895documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]1896need to be documented). This is probably best done by reference to another
1897document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1898</p>
1899
1900</div>
1901
1902<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1903<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1904<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1905
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1906<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1907
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1908<p>The LLVM instruction set consists of several different
1909classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1910instructions</a>, <a href="#binaryops">binary instructions</a>,
1911<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1912 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1913instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1914
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1915</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1916
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1917<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1918<div class="doc_subsection"> <a name="terminators">Terminator
1919Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1920
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1921<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1922
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1923<p>As mentioned <a href="#functionstructure">previously</a>, every
1924basic block in a program ends with a "Terminator" instruction, which
1925indicates which block should be executed after the current block is
1926finished. These terminator instructions typically yield a '<tt>void</tt>'
1927value: they produce control flow, not values (the one exception being
1928the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1929<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1930 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1931instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1932the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1933 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1934 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1935
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1936</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1937
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1938<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1939<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1940Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1941<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1942<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1943<pre>
1944 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]1945 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1946</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1947
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1948<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1949
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1950<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1951optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1952<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1953returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1954control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1955
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1956<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1957
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1958<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1959the return value. The type of the return value must be a
1960'<a href="#t_firstclass">first class</a>' type.</p>
1961
1962<p>A function is not <a href="#wellformed">well formed</a> if
1963it it has a non-void return type and contains a '<tt>ret</tt>'
1964instruction with no return value or a return value with a type that
1965does not match its type, or if it has a void return type and contains
1966a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1967
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1968<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1969
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1970<p>When the '<tt>ret</tt>' instruction is executed, control flow
1971returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1972 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1973the instruction after the call. If the caller was an "<a
1974 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1975at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1976returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1977return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1978
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1979<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1980
1981<pre>
1982 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1983 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1984 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]1985</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1986</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1987<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1988<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1989<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1990<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1991<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]1992</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1993<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1994<p>The '<tt>br</tt>' instruction is used to cause control flow to
1995transfer to a different basic block in the current function. There are
1996two forms of this instruction, corresponding to a conditional branch
1997and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1998<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1999<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2000single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]2001unconditional form of the '<tt>br</tt>' instruction takes a single
2002'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2003<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2004<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2005argument is evaluated. If the value is <tt>true</tt>, control flows
2006to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2007control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2008<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2009<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]2010 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]2011</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2012<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2013<div class="doc_subsubsection">
2014 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2015</div>
2016
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2017<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2018<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2019
2020<pre>
2021 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2022</pre>
2023
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2024<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2025
2026<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2027several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2028instruction, allowing a branch to occur to one of many possible
2029destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2030
2031
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2032<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2033
2034<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2035comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2036an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2037table is not allowed to contain duplicate constant entries.</p>
2038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2039<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2040
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2041<p>The <tt>switch</tt> instruction specifies a table of values and
2042destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2043table is searched for the given value. If the value is found, control flow is
2044transfered to the corresponding destination; otherwise, control flow is
2045transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2046
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2047<h5>Implementation:</h5>
2048
2049<p>Depending on properties of the target machine and the particular
2050<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2051ways. For example, it could be generated as a series of chained conditional
2052branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2053
2054<h5>Example:</h5>
2055
2056<pre>
2057 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2058 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2059 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2060
2061 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2062 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2063
2064 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2065 switch i32 %val, label %otherwise [ i32 0, label %onzero
2066 i32 1, label %onone
2067 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2068</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2069</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2070
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2071<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2072<div class="doc_subsubsection">
2073 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2074</div>
2075
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2076<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2077
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2078<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2079
2080<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2081 &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]2082 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2083</pre>
2084
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2085<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2086
2087<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2088function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2089'<tt>normal</tt>' label or the
2090'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2091"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2092"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2093href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2094continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2095
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2096<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2097
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2098<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2099
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2100<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2101 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2102 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2103 convention</a> the call should use. If none is specified, the call defaults
2104 to using C calling conventions.
2105 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2106
2107 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2108 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2109 and '<tt>inreg</tt>' attributes are valid here.</li>
2110
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2111 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2112 function value being invoked. In most cases, this is a direct function
2113 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2114 an arbitrary pointer to function value.
2115 </li>
2116
2117 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2118 function to be invoked. </li>
2119
2120 <li>'<tt>function args</tt>': argument list whose types match the function
2121 signature argument types. If the function signature indicates the function
2122 accepts a variable number of arguments, the extra arguments can be
2123 specified. </li>
2124
2125 <li>'<tt>normal label</tt>': the label reached when the called function
2126 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2127
2128 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2129 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2130
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2131 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2132 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2133 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2134</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2135
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2136<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2137
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2138<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2139href="#i_call">call</a></tt>' instruction in most regards. The primary
2140difference is that it establishes an association with a label, which is used by
2141the runtime library to unwind the stack.</p>
2142
2143<p>This instruction is used in languages with destructors to ensure that proper
2144cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2145exception. Additionally, this is important for implementation of
2146'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2147
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2148<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2149<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2150 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2151 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2152 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2153 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2154</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2155</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2156
2157
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2158<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2159
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2160<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2161Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2162
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2163<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2164
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2165<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2166<pre>
2167 unwind
2168</pre>
2169
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2170<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2171
2172<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2173at the first callee in the dynamic call stack which used an <a
2174href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2175primarily used to implement exception handling.</p>
2176
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2177<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2178
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2179<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2180immediately halt. The dynamic call stack is then searched for the first <a
2181href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2182execution continues at the "exceptional" destination block specified by the
2183<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2184dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2185</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2186
2187<!-- _______________________________________________________________________ -->
2188
2189<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2190Instruction</a> </div>
2191
2192<div class="doc_text">
2193
2194<h5>Syntax:</h5>
2195<pre>
2196 unreachable
2197</pre>
2198
2199<h5>Overview:</h5>
2200
2201<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2202instruction is used to inform the optimizer that a particular portion of the
2203code is not reachable. This can be used to indicate that the code after a
2204no-return function cannot be reached, and other facts.</p>
2205
2206<h5>Semantics:</h5>
2207
2208<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2209</div>
2210
2211
2212
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2213<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2214<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2215<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2216<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2217program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2218produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2219multiple 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]2220The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2221<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2222</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2223<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2224<div class="doc_subsubsection">
2225 <a name="i_add">'<tt>add</tt>' Instruction</a>
2226</div>
2227
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2228<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2229
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2230<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2231
2232<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2233 &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]2234</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2235
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2236<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2237
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2238<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2239
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2240<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2241
2242<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2243 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2244 <a href="#t_vector">vector</a> values. Both arguments must have identical
2245 types.</p>
2246
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2247<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2248
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2249<p>The value produced is the integer or floating point sum of the two
2250operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2251
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2252<p>If an integer sum has unsigned overflow, the result returned is the
2253mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2254the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2255
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2256<p>Because LLVM integers use a two's complement representation, this
2257instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2258
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2259<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2260
2261<pre>
2262 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2263</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2264</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2265<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2266<div class="doc_subsubsection">
2267 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2268</div>
2269
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2270<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2271
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2272<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2273
2274<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2275 &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]2276</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2277
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2278<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2279
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2280<p>The '<tt>sub</tt>' instruction returns the difference of its two
2281operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2282
2283<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2284'<tt>neg</tt>' instruction present in most other intermediate
2285representations.</p>
2286
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2287<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2288
2289<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2290 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2291 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2292 types.</p>
2293
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2294<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2295
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2296<p>The value produced is the integer or floating point difference of
2297the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2298
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2299<p>If an integer difference has unsigned overflow, the result returned is the
2300mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2301the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2302
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2303<p>Because LLVM integers use a two's complement representation, this
2304instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2305
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2306<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2307<pre>
2308 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2309 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2310</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2311</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2312
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2313<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2314<div class="doc_subsubsection">
2315 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2316</div>
2317
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2318<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2319
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2320<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2321<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]2322</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2323<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2324<p>The '<tt>mul</tt>' instruction returns the product of its two
2325operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2327<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2328
2329<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2330href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2331or <a href="#t_vector">vector</a> values. Both arguments must have identical
2332types.</p>
2333
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2334<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2335
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2336<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2337two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2338
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2339<p>If the result of an integer multiplication has unsigned overflow,
2340the result returned is the mathematical result modulo
23412<sup>n</sup>, where n is the bit width of the result.</p>
2342<p>Because LLVM integers use a two's complement representation, and the
2343result is the same width as the operands, this instruction returns the
2344correct result for both signed and unsigned integers. If a full product
2345(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2346should be sign-extended or zero-extended as appropriate to the
2347width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2348<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2349<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]2350</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2351</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2352
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2353<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2354<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2355</a></div>
2356<div class="doc_text">
2357<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2358<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]2359</pre>
2360<h5>Overview:</h5>
2361<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2362operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2363
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2364<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2365
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2366<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2367<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2368values. Both arguments must have identical types.</p>
2369
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2370<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2371
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2372<p>The value produced is the unsigned integer quotient of the two operands.</p>
2373<p>Note that unsigned integer division and signed integer division are distinct
2374operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2375<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2376<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2377<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]2378</pre>
2379</div>
2380<!-- _______________________________________________________________________ -->
2381<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2382</a> </div>
2383<div class="doc_text">
2384<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2385<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2386 &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]2387</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2388
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2389<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2390
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2391<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2392operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2393
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2394<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2395
2396<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2397<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2398values. Both arguments must have identical types.</p>
2399
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2400<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2401<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]2402<p>Note that signed integer division and unsigned integer division are distinct
2403operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2404<p>Division by zero leads to undefined behavior. Overflow also leads to
2405undefined behavior; this is a rare case, but can occur, for example,
2406by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2407<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2408<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]2409</pre>
2410</div>
2411<!-- _______________________________________________________________________ -->
2412<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2413Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2414<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2415<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2416<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2417 &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]2418</pre>
2419<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2420
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2421<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2422operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2423
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2424<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2425
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2426<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2427<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2428of floating point values. Both arguments must have identical types.</p>
2429
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2430<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2431
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2432<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2433
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2434<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2435
2436<pre>
2437 &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]2438</pre>
2439</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2440
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2441<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2442<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2443</div>
2444<div class="doc_text">
2445<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2446<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]2447</pre>
2448<h5>Overview:</h5>
2449<p>The '<tt>urem</tt>' instruction returns the remainder from the
2450unsigned division of its two arguments.</p>
2451<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2452<p>The two arguments to the '<tt>urem</tt>' instruction must be
2453<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2454values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2455<h5>Semantics:</h5>
2456<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2457This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2458<p>Note that unsigned integer remainder and signed integer remainder are
2459distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2460<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2461<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2462<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]2463</pre>
2464
2465</div>
2466<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2467<div class="doc_subsubsection">
2468 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2469</div>
2470
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2471<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2472
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2473<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2474
2475<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2476 &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]2477</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2478
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2479<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2480
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2481<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2482signed division of its two operands. This instruction can also take
2483<a href="#t_vector">vector</a> versions of the values in which case
2484the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +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
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2488<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2489<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2490values. 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 Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2494<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2495has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2496operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2497a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2498 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2499Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2500please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2501Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2502<p>Note that signed integer remainder and unsigned integer remainder are
2503distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2504<p>Taking the remainder of a division by zero leads to undefined behavior.
2505Overflow also leads to undefined behavior; this is a rare case, but can occur,
2506for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2507(The remainder doesn't actually overflow, but this rule lets srem be
2508implemented using instructions that return both the result of the division
2509and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2510<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2511<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]2512</pre>
2513
2514</div>
2515<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2516<div class="doc_subsubsection">
2517 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2518
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2519<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2520
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2521<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2522<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]2523</pre>
2524<h5>Overview:</h5>
2525<p>The '<tt>frem</tt>' instruction returns the remainder from the
2526division of its two operands.</p>
2527<h5>Arguments:</h5>
2528<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2529<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2530of floating point values. Both arguments must have identical types.</p>
2531
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2532<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2533
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2534<p>This instruction returns the <i>remainder</i> of a division.
2535The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2536
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2537<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2538
2539<pre>
2540 &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]2541</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2542</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2543
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2544<!-- ======================================================================= -->
2545<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2546Operations</a> </div>
2547<div class="doc_text">
2548<p>Bitwise binary operators are used to do various forms of
2549bit-twiddling in a program. They are generally very efficient
2550instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2551instructions. They require two operands of the same type, execute an operation on them,
2552and 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]2553</div>
2554
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2555<!-- _______________________________________________________________________ -->
2556<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2557Instruction</a> </div>
2558<div class="doc_text">
2559<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2560<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]2561</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2562
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2563<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2564
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2565<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2566the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2567
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2568<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2569
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2570<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2571 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2572type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2573
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2574<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2575
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2576<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2577where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2578equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2579
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2580<h5>Example:</h5><pre>
2581 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2582 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2583 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2584 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2585</pre>
2586</div>
2587<!-- _______________________________________________________________________ -->
2588<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2589Instruction</a> </div>
2590<div class="doc_text">
2591<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2592<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]2593</pre>
2594
2595<h5>Overview:</h5>
2596<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2597operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2598
2599<h5>Arguments:</h5>
2600<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2601<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]2602type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2603
2604<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2605
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2606<p>This instruction always performs a logical shift right operation. The most
2607significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2608shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2609the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2610
2611<h5>Example:</h5>
2612<pre>
2613 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2614 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2615 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2616 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2617 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2618</pre>
2619</div>
2620
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2621<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2622<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2623Instruction</a> </div>
2624<div class="doc_text">
2625
2626<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2627<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]2628</pre>
2629
2630<h5>Overview:</h5>
2631<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2632operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2633
2634<h5>Arguments:</h5>
2635<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2636<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]2637type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2638
2639<h5>Semantics:</h5>
2640<p>This instruction always performs an arithmetic shift right operation,
2641The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2642of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2643larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2644</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2645
2646<h5>Example:</h5>
2647<pre>
2648 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2649 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2650 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2651 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2652 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2653</pre>
2654</div>
2655
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2656<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2657<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2658Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2659
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2660<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2661
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2662<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2663
2664<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2665 &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]2666</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2667
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2668<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2669
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2670<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2671its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2672
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2673<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2674
2675<p>The two arguments to the '<tt>and</tt>' instruction must be
2676<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2677values. Both arguments must have identical types.</p>
2678
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2679<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2680<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2681<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2682<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2683<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2684 <tbody>
2685 <tr>
2686 <td>In0</td>
2687 <td>In1</td>
2688 <td>Out</td>
2689 </tr>
2690 <tr>
2691 <td>0</td>
2692 <td>0</td>
2693 <td>0</td>
2694 </tr>
2695 <tr>
2696 <td>0</td>
2697 <td>1</td>
2698 <td>0</td>
2699 </tr>
2700 <tr>
2701 <td>1</td>
2702 <td>0</td>
2703 <td>0</td>
2704 </tr>
2705 <tr>
2706 <td>1</td>
2707 <td>1</td>
2708 <td>1</td>
2709 </tr>
2710 </tbody>
2711</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2712</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2713<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2714<pre>
2715 &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]2716 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2717 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2718</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2719</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2720<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2721<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2722<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2723<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2724<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]2725</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2726<h5>Overview:</h5>
2727<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2728or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2729<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2730
2731<p>The two arguments to the '<tt>or</tt>' instruction must be
2732<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2733values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2734<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2735<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2736<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2737<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2738<table border="1" cellspacing="0" cellpadding="4">
2739 <tbody>
2740 <tr>
2741 <td>In0</td>
2742 <td>In1</td>
2743 <td>Out</td>
2744 </tr>
2745 <tr>
2746 <td>0</td>
2747 <td>0</td>
2748 <td>0</td>
2749 </tr>
2750 <tr>
2751 <td>0</td>
2752 <td>1</td>
2753 <td>1</td>
2754 </tr>
2755 <tr>
2756 <td>1</td>
2757 <td>0</td>
2758 <td>1</td>
2759 </tr>
2760 <tr>
2761 <td>1</td>
2762 <td>1</td>
2763 <td>1</td>
2764 </tr>
2765 </tbody>
2766</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2767</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2768<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2769<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2770 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2771 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2772</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2773</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2774<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2775<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2776Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2777<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2778<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2779<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]2780</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2781<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2782<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2783or of its two operands. The <tt>xor</tt> is used to implement the
2784"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2785<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2786<p>The two arguments to the '<tt>xor</tt>' instruction must be
2787<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2788values. Both arguments must have identical types.</p>
2789
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2790<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2791
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2792<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2793<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2794<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2795<table border="1" cellspacing="0" cellpadding="4">
2796 <tbody>
2797 <tr>
2798 <td>In0</td>
2799 <td>In1</td>
2800 <td>Out</td>
2801 </tr>
2802 <tr>
2803 <td>0</td>
2804 <td>0</td>
2805 <td>0</td>
2806 </tr>
2807 <tr>
2808 <td>0</td>
2809 <td>1</td>
2810 <td>1</td>
2811 </tr>
2812 <tr>
2813 <td>1</td>
2814 <td>0</td>
2815 <td>1</td>
2816 </tr>
2817 <tr>
2818 <td>1</td>
2819 <td>1</td>
2820 <td>0</td>
2821 </tr>
2822 </tbody>
2823</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2824</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2825<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2826<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2827<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2828 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2829 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2830 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2831</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2832</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2833
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2834<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2835<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2836 <a name="vectorops">Vector Operations</a>
2837</div>
2838
2839<div class="doc_text">
2840
2841<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2842target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2843vector-specific operations needed to process vectors effectively. While LLVM
2844does directly support these vector operations, many sophisticated algorithms
2845will want to use target-specific intrinsics to take full advantage of a specific
2846target.</p>
2847
2848</div>
2849
2850<!-- _______________________________________________________________________ -->
2851<div class="doc_subsubsection">
2852 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2853</div>
2854
2855<div class="doc_text">
2856
2857<h5>Syntax:</h5>
2858
2859<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2860 &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]2861</pre>
2862
2863<h5>Overview:</h5>
2864
2865<p>
2866The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2867element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2868</p>
2869
2870
2871<h5>Arguments:</h5>
2872
2873<p>
2874The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2875value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2876an index indicating the position from which to extract the element.
2877The index may be a variable.</p>
2878
2879<h5>Semantics:</h5>
2880
2881<p>
2882The result is a scalar of the same type as the element type of
2883<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2884<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2885results are undefined.
2886</p>
2887
2888<h5>Example:</h5>
2889
2890<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2891 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2892</pre>
2893</div>
2894
2895
2896<!-- _______________________________________________________________________ -->
2897<div class="doc_subsubsection">
2898 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2899</div>
2900
2901<div class="doc_text">
2902
2903<h5>Syntax:</h5>
2904
2905<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2906 &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]2907</pre>
2908
2909<h5>Overview:</h5>
2910
2911<p>
2912The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2913element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2914</p>
2915
2916
2917<h5>Arguments:</h5>
2918
2919<p>
2920The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2921value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2922scalar value whose type must equal the element type of the first
2923operand. The third operand is an index indicating the position at
2924which to insert the value. The index may be a variable.</p>
2925
2926<h5>Semantics:</h5>
2927
2928<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2929The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2930element values are those of <tt>val</tt> except at position
2931<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2932exceeds the length of <tt>val</tt>, the results are undefined.
2933</p>
2934
2935<h5>Example:</h5>
2936
2937<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2938 %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]2939</pre>
2940</div>
2941
2942<!-- _______________________________________________________________________ -->
2943<div class="doc_subsubsection">
2944 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2945</div>
2946
2947<div class="doc_text">
2948
2949<h5>Syntax:</h5>
2950
2951<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2952 &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]2953</pre>
2954
2955<h5>Overview:</h5>
2956
2957<p>
2958The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2959from two input vectors, returning a vector with the same element type as
2960the input and length that is the same as the shuffle mask.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2961</p>
2962
2963<h5>Arguments:</h5>
2964
2965<p>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2966The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2967with types that match each other. The third argument is a shuffle mask whose
2968element type is always 'i32'. The result of the instruction is a vector whose
2969length is the same as the shuffle mask and whose element type is the same as
2970the element type of the first two operands.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2971</p>
2972
2973<p>
2974The shuffle mask operand is required to be a constant vector with either
2975constant integer or undef values.
2976</p>
2977
2978<h5>Semantics:</h5>
2979
2980<p>
2981The elements of the two input vectors are numbered from left to right across
2982both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2983the result vector, which element of the two input vectors the result element
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2984gets. The element selector may be undef (meaning "don't care") and the second
2985operand may be undef if performing a shuffle from only one vector.
2986</p>
2987
2988<h5>Example:</h5>
2989
2990<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2991 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2992 &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]2993 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2994 &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]2995 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
2996 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
2997 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
2998 &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]2999</pre>
3000</div>
3001
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3002
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3003<!-- ======================================================================= -->
3004<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3005 <a name="aggregateops">Aggregate Operations</a>
3006</div>
3007
3008<div class="doc_text">
3009
3010<p>LLVM supports several instructions for working with aggregate values.
3011</p>
3012
3013</div>
3014
3015<!-- _______________________________________________________________________ -->
3016<div class="doc_subsubsection">
3017 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3018</div>
3019
3020<div class="doc_text">
3021
3022<h5>Syntax:</h5>
3023
3024<pre>
3025 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3026</pre>
3027
3028<h5>Overview:</h5>
3029
3030<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3031The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3032or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3033</p>
3034
3035
3036<h5>Arguments:</h5>
3037
3038<p>
3039The first operand of an '<tt>extractvalue</tt>' instruction is a
3040value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3041type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3042in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3043'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3044</p>
3045
3046<h5>Semantics:</h5>
3047
3048<p>
3049The result is the value at the position in the aggregate specified by
3050the index operands.
3051</p>
3052
3053<h5>Example:</h5>
3054
3055<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3056 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3057</pre>
3058</div>
3059
3060
3061<!-- _______________________________________________________________________ -->
3062<div class="doc_subsubsection">
3063 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3064</div>
3065
3066<div class="doc_text">
3067
3068<h5>Syntax:</h5>
3069
3070<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3071 &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]3072</pre>
3073
3074<h5>Overview:</h5>
3075
3076<p>
3077The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3078into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3079</p>
3080
3081
3082<h5>Arguments:</h5>
3083
3084<p>
3085The first operand of an '<tt>insertvalue</tt>' instruction is a
3086value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3087The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3088The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3089indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3090indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3091'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3092The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3093by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3094</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3095
3096<h5>Semantics:</h5>
3097
3098<p>
3099The result is an aggregate of the same type as <tt>val</tt>. Its
3100value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3101specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3102</p>
3103
3104<h5>Example:</h5>
3105
3106<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3107 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3108</pre>
3109</div>
3110
3111
3112<!-- ======================================================================= -->
3113<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3114 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3115</div>
3116
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3117<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3118
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3119<p>A key design point of an SSA-based representation is how it
3120represents memory. In LLVM, no memory locations are in SSA form, which
3121makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3122allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3123
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3124</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3125
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3126<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3127<div class="doc_subsubsection">
3128 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3129</div>
3130
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3131<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3132
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3133<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3134
3135<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3136 &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]3137</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3138
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3139<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3140
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3141<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3142heap and returns a pointer to it. The object is always allocated in the generic
3143address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3144
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3145<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3146
3147<p>The '<tt>malloc</tt>' instruction allocates
3148<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3149bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3150appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3151number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3152If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3153be aligned to at least that boundary. If not specified, or if zero, the target can
3154choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3155
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3156<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3157
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3158<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3159
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3160<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3161a pointer is returned. The result of a zero byte allocattion is undefined. The
3162result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3163
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3164<h5>Example:</h5>
3165
3166<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3167 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3168
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3169 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3170 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3171 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3172 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3173 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3174</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3175</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3176
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3177<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3178<div class="doc_subsubsection">
3179 <a name="i_free">'<tt>free</tt>' Instruction</a>
3180</div>
3181
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3182<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3183
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3184<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3185
3186<pre>
3187 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3188</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3189
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3190<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3191
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3192<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3193memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3194
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3195<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3196
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3197<p>'<tt>value</tt>' shall be a pointer value that points to a value
3198that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3199instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3200
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3201<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3202
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3203<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3204after this instruction executes. If the pointer is null, the operation
3205is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3206
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3207<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3208
3209<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3210 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3211 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3212</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3213</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3214
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3215<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3216<div class="doc_subsubsection">
3217 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3218</div>
3219
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3220<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3221
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3222<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3223
3224<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3225 &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]3226</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3227
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3228<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3229
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3230<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3231currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3232returns to its caller. The object is always allocated in the generic address
3233space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3234
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3235<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3236
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3237<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3238bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3239appropriate type to the program. If "NumElements" is specified, it is the
3240number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3241If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3242to be aligned to at least that boundary. If not specified, or if zero, the target
3243can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3244
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3245<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3246
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3247<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3248
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3249<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3250there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3251memory is automatically released when the function returns. The '<tt>alloca</tt>'
3252instruction is commonly used to represent automatic variables that must
3253have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3254 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]3255instructions), the memory is reclaimed. Allocating zero bytes
3256is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3257
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3258<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3259
3260<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3261 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3262 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3263 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3264 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3265</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3266</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3267
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3268<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3269<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3270Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3271<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3272<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3273<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]3274<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3275<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3276<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3277<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3278address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3279 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3280marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3281the number or order of execution of this <tt>load</tt> with other
3282volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3283instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3284<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3285The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3286(that is, the alignment of the memory address). A value of 0 or an
3287omitted "align" argument means that the operation has the preferential
3288alignment for the target. It is the responsibility of the code emitter
3289to ensure that the alignment information is correct. Overestimating
3290the alignment results in an undefined behavior. Underestimating the
3291alignment may produce less efficient code. An alignment of 1 is always
3292safe.
3293</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3294<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3295<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3296<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3297<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3298 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3299 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3300 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3301</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3302</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3303<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3304<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3305Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3306<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3307<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3308<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3309 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]3310</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3311<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3312<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3313<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3314<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3315to 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]3316operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3317of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3318operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3319optimizer is not allowed to modify the number or order of execution of
3320this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3321 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3322<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3323The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3324(that is, the alignment of the memory address). A value of 0 or an
3325omitted "align" argument means that the operation has the preferential
3326alignment for the target. It is the responsibility of the code emitter
3327to ensure that the alignment information is correct. Overestimating
3328the alignment results in an undefined behavior. Underestimating the
3329alignment may produce less efficient code. An alignment of 1 is always
3330safe.
3331</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3332<h5>Semantics:</h5>
3333<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3334at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3335<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3336<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3337 store i32 3, i32* %ptr <i>; yields {void}</i>
3338 %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]3339</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3340</div>
3341
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3342<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3343<div class="doc_subsubsection">
3344 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3345</div>
3346
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3347<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3348<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3349<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3350 &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]3351</pre>
3352
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3353<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3354
3355<p>
3356The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3357subelement of an aggregate data structure. It performs address calculation only
3358and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3359
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3360<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3361
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3362<p>The first argument is always a pointer, and forms the basis of the
3363calculation. The remaining arguments are indices, that indicate which of the
3364elements of the aggregate object are indexed. The interpretation of each index
3365is dependent on the type being indexed into. The first index always indexes the
3366pointer value given as the first argument, the second index indexes a value of
3367the type pointed to (not necessarily the value directly pointed to, since the
3368first index can be non-zero), etc. The first type indexed into must be a pointer
3369value, subsequent types can be arrays, vectors and structs. Note that subsequent
3370types being indexed into can never be pointers, since that would require loading
3371the pointer before continuing calculation.</p>
3372
3373<p>The type of each index argument depends on the type it is indexing into.
3374When indexing into a (packed) structure, only <tt>i32</tt> integer
3375<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3376only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3377will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3378
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3379<p>For example, let's consider a C code fragment and how it gets
3380compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3381
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3382<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3383<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3384struct RT {
3385 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3386 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3387 char C;
3388};
3389struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3390 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3391 double Y;
3392 struct RT Z;
3393};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3394
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3395int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3396 return &amp;s[1].Z.B[5][13];
3397}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3398</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3399</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3400
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3401<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3402
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3403<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3404<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3405%RT = type { i8 , [10 x [20 x i32]], i8 }
3406%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3407
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3408define i32* %foo(%ST* %s) {
3409entry:
3410 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3411 ret i32* %reg
3412}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3413</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3414</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3415
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3416<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3417
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3418<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]3419type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3420}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3421the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3422i8 }</tt>' type, another structure. The third index indexes into the second
3423element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3424array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3425'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3426to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3427
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3428<p>Note that it is perfectly legal to index partially through a
3429structure, returning a pointer to an inner element. Because of this,
3430the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3431
3432<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3433 define i32* %foo(%ST* %s) {
3434 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3435 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3436 %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]3437 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3438 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3439 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3440 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3441</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3442
3443<p>Note that it is undefined to access an array out of bounds: array and
3444pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3445The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3446defined to be accessible as variable length arrays, which requires access
3447beyond the zero'th element.</p>
3448
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3449<p>The getelementptr instruction is often confusing. For some more insight
3450into how it works, see <a href="GetElementPtr.html">the getelementptr
3451FAQ</a>.</p>
3452
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3453<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3454
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3455<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3456 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3457 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3458 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3459 %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]3460 <i>; yields i8*:eptr</i>
3461 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3462</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3463</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3464
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3465<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3466<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3467</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3468<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3469<p>The instructions in this category are the conversion instructions (casting)
3470which all take a single operand and a type. They perform various bit conversions
3471on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3472</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3473
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3474<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3475<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3476 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3477</div>
3478<div class="doc_text">
3479
3480<h5>Syntax:</h5>
3481<pre>
3482 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3483</pre>
3484
3485<h5>Overview:</h5>
3486<p>
3487The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3488</p>
3489
3490<h5>Arguments:</h5>
3491<p>
3492The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3493be 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]3494and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3495type. The bit size of <tt>value</tt> must be larger than the bit size of
3496<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3497
3498<h5>Semantics:</h5>
3499<p>
3500The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3501and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3502larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3503It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3504
3505<h5>Example:</h5>
3506<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3507 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3508 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3509 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3510</pre>
3511</div>
3512
3513<!-- _______________________________________________________________________ -->
3514<div class="doc_subsubsection">
3515 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3516</div>
3517<div class="doc_text">
3518
3519<h5>Syntax:</h5>
3520<pre>
3521 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3522</pre>
3523
3524<h5>Overview:</h5>
3525<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3526<tt>ty2</tt>.</p>
3527
3528
3529<h5>Arguments:</h5>
3530<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]3531<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3532also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3533<tt>value</tt> must be smaller than the bit size of the destination type,
3534<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3535
3536<h5>Semantics:</h5>
3537<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]3538bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3539
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3540<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]3541
3542<h5>Example:</h5>
3543<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3544 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3545 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3546</pre>
3547</div>
3548
3549<!-- _______________________________________________________________________ -->
3550<div class="doc_subsubsection">
3551 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3552</div>
3553<div class="doc_text">
3554
3555<h5>Syntax:</h5>
3556<pre>
3557 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3558</pre>
3559
3560<h5>Overview:</h5>
3561<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3562
3563<h5>Arguments:</h5>
3564<p>
3565The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3566<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3567also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3568<tt>value</tt> must be smaller than the bit size of the destination type,
3569<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3570
3571<h5>Semantics:</h5>
3572<p>
3573The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3574bit (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]3575the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3576
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3577<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]3578
3579<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3580<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3581 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3582 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3583</pre>
3584</div>
3585
3586<!-- _______________________________________________________________________ -->
3587<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3588 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3589</div>
3590
3591<div class="doc_text">
3592
3593<h5>Syntax:</h5>
3594
3595<pre>
3596 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3597</pre>
3598
3599<h5>Overview:</h5>
3600<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3601<tt>ty2</tt>.</p>
3602
3603
3604<h5>Arguments:</h5>
3605<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3606 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3607cast it to. The size of <tt>value</tt> must be larger than the size of
3608<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3609<i>no-op cast</i>.</p>
3610
3611<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3612<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3613<a href="#t_floating">floating point</a> type to a smaller
3614<a href="#t_floating">floating point</a> type. If the value cannot fit within
3615the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3616
3617<h5>Example:</h5>
3618<pre>
3619 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3620 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3621</pre>
3622</div>
3623
3624<!-- _______________________________________________________________________ -->
3625<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3626 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3627</div>
3628<div class="doc_text">
3629
3630<h5>Syntax:</h5>
3631<pre>
3632 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3633</pre>
3634
3635<h5>Overview:</h5>
3636<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3637floating point value.</p>
3638
3639<h5>Arguments:</h5>
3640<p>The '<tt>fpext</tt>' instruction takes a
3641<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3642and a <a href="#t_floating">floating point</a> type to cast it to. The source
3643type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3644
3645<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3646<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3647<a href="#t_floating">floating point</a> type to a larger
3648<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3649used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3650<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]3651
3652<h5>Example:</h5>
3653<pre>
3654 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3655 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3656</pre>
3657</div>
3658
3659<!-- _______________________________________________________________________ -->
3660<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3661 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3662</div>
3663<div class="doc_text">
3664
3665<h5>Syntax:</h5>
3666<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3667 &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]3668</pre>
3669
3670<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3671<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3672unsigned integer equivalent of type <tt>ty2</tt>.
3673</p>
3674
3675<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3676<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]3677scalar or vector <a href="#t_floating">floating point</a> value, and a type
3678to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3679type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3680vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3681
3682<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3683<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3684<a href="#t_floating">floating point</a> operand into the nearest (rounding
3685towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3686the results are undefined.</p>
3687
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3688<h5>Example:</h5>
3689<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3690 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3691 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3692 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3693</pre>
3694</div>
3695
3696<!-- _______________________________________________________________________ -->
3697<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3698 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3699</div>
3700<div class="doc_text">
3701
3702<h5>Syntax:</h5>
3703<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3704 &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]3705</pre>
3706
3707<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3708<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3709<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]3710</p>
3711
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3712<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3713<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]3714scalar or vector <a href="#t_floating">floating point</a> value, and a type
3715to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3716type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3717vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3718
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3719<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3720<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3721<a href="#t_floating">floating point</a> operand into the nearest (rounding
3722towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3723the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3724
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3725<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3726<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3727 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3728 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3729 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3730</pre>
3731</div>
3732
3733<!-- _______________________________________________________________________ -->
3734<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3735 <a name="i_uitofp">'<tt>uitofp .. 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 Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3741 &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]3742</pre>
3743
3744<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3745<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3746integer and converts that value to the <tt>ty2</tt> type.</p>
3747
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3748<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3749<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3750scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3751to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3752type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3753floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3754
3755<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3756<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3757integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3758the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3759
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3760<h5>Example:</h5>
3761<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3762 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3763 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3764</pre>
3765</div>
3766
3767<!-- _______________________________________________________________________ -->
3768<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3769 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3770</div>
3771<div class="doc_text">
3772
3773<h5>Syntax:</h5>
3774<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3775 &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]3776</pre>
3777
3778<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3779<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3780integer and converts that value to the <tt>ty2</tt> type.</p>
3781
3782<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3783<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3784scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3785to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3786type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3787floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3788
3789<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3790<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3791integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3792the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3793
3794<h5>Example:</h5>
3795<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3796 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3797 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3798</pre>
3799</div>
3800
3801<!-- _______________________________________________________________________ -->
3802<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3803 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3804</div>
3805<div class="doc_text">
3806
3807<h5>Syntax:</h5>
3808<pre>
3809 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3810</pre>
3811
3812<h5>Overview:</h5>
3813<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3814the integer type <tt>ty2</tt>.</p>
3815
3816<h5>Arguments:</h5>
3817<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3818must 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]3819<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]3820
3821<h5>Semantics:</h5>
3822<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3823<tt>ty2</tt> by interpreting the pointer value as an integer and either
3824truncating or zero extending that value to the size of the integer type. If
3825<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3826<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]3827are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3828change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3829
3830<h5>Example:</h5>
3831<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3832 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3833 %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]3834</pre>
3835</div>
3836
3837<!-- _______________________________________________________________________ -->
3838<div class="doc_subsubsection">
3839 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3840</div>
3841<div class="doc_text">
3842
3843<h5>Syntax:</h5>
3844<pre>
3845 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3846</pre>
3847
3848<h5>Overview:</h5>
3849<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3850a pointer type, <tt>ty2</tt>.</p>
3851
3852<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3853<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3854value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3855<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3856
3857<h5>Semantics:</h5>
3858<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3859<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3860the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3861size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3862the size of a pointer then a zero extension is done. If they are the same size,
3863nothing is done (<i>no-op cast</i>).</p>
3864
3865<h5>Example:</h5>
3866<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3867 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3868 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3869 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3870</pre>
3871</div>
3872
3873<!-- _______________________________________________________________________ -->
3874<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3875 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3876</div>
3877<div class="doc_text">
3878
3879<h5>Syntax:</h5>
3880<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3881 &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]3882</pre>
3883
3884<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3885
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3886<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3887<tt>ty2</tt> without changing any bits.</p>
3888
3889<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3890
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3891<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]3892a non-aggregate first class value, and a type to cast it to, which must also be
3893a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3894<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3895and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3896type is a pointer, the destination type must also be a pointer. This
3897instruction supports bitwise conversion of vectors to integers and to vectors
3898of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3899
3900<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3901<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3902<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3903this conversion. The conversion is done as if the <tt>value</tt> had been
3904stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3905converted to other pointer types with this instruction. To convert pointers to
3906other types, use the <a href="#i_inttoptr">inttoptr</a> or
3907<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3908
3909<h5>Example:</h5>
3910<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3911 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3912 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3913 %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]3914</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3915</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3916
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3917<!-- ======================================================================= -->
3918<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3919<div class="doc_text">
3920<p>The instructions in this category are the "miscellaneous"
3921instructions, which defy better classification.</p>
3922</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3923
3924<!-- _______________________________________________________________________ -->
3925<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3926</div>
3927<div class="doc_text">
3928<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3929<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]3930</pre>
3931<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3932<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3933a vector of boolean values based on comparison
3934of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3935<h5>Arguments:</h5>
3936<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3937the condition code indicating the kind of comparison to perform. It is not
3938a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3939</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3940<ol>
3941 <li><tt>eq</tt>: equal</li>
3942 <li><tt>ne</tt>: not equal </li>
3943 <li><tt>ugt</tt>: unsigned greater than</li>
3944 <li><tt>uge</tt>: unsigned greater or equal</li>
3945 <li><tt>ult</tt>: unsigned less than</li>
3946 <li><tt>ule</tt>: unsigned less or equal</li>
3947 <li><tt>sgt</tt>: signed greater than</li>
3948 <li><tt>sge</tt>: signed greater or equal</li>
3949 <li><tt>slt</tt>: signed less than</li>
3950 <li><tt>sle</tt>: signed less or equal</li>
3951</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3952<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3953<a href="#t_pointer">pointer</a>
3954or integer <a href="#t_vector">vector</a> typed.
3955They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3956<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3957<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]3958the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3959yields 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]3960</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3961<ol>
3962 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3963 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3964 </li>
3965 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3966 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3967 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3968 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3969 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3970 <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]3971 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3972 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3973 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3974 <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]3975 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3976 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3977 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3978 <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]3979 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3980 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3981 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3982 <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]3983</ol>
3984<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3985values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3986<p>If the operands are integer vectors, then they are compared
3987element by element. The result is an <tt>i1</tt> vector with
3988the same number of elements as the values being compared.
3989Otherwise, the result is an <tt>i1</tt>.
3990</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3991
3992<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3993<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3994 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3995 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3996 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3997 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3998 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3999</pre>
4000</div>
4001
4002<!-- _______________________________________________________________________ -->
4003<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4004</div>
4005<div class="doc_text">
4006<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4007<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]4008</pre>
4009<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4010<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4011or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4012of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4013<p>
4014If the operands are floating point scalars, then the result
4015type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4016</p>
4017<p>If the operands are floating point vectors, then the result type
4018is a vector of boolean with the same number of elements as the
4019operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4020<h5>Arguments:</h5>
4021<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4022the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4023a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4024<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4025 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4026 <li><tt>oeq</tt>: ordered and equal</li>
4027 <li><tt>ogt</tt>: ordered and greater than </li>
4028 <li><tt>oge</tt>: ordered and greater than or equal</li>
4029 <li><tt>olt</tt>: ordered and less than </li>
4030 <li><tt>ole</tt>: ordered and less than or equal</li>
4031 <li><tt>one</tt>: ordered and not equal</li>
4032 <li><tt>ord</tt>: ordered (no nans)</li>
4033 <li><tt>ueq</tt>: unordered or equal</li>
4034 <li><tt>ugt</tt>: unordered or greater than </li>
4035 <li><tt>uge</tt>: unordered or greater than or equal</li>
4036 <li><tt>ult</tt>: unordered or less than </li>
4037 <li><tt>ule</tt>: unordered or less than or equal</li>
4038 <li><tt>une</tt>: unordered or not equal</li>
4039 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4040 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4041</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4042<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4043<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4044<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4045either a <a href="#t_floating">floating point</a> type
4046or a <a href="#t_vector">vector</a> of floating point type.
4047They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4048<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4049<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4050according to the condition code given as <tt>cond</tt>.
4051If the operands are vectors, then the vectors are compared
4052element by element.
4053Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4054always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4055<ol>
4056 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4057 <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]4058 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4059 <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]4060 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4061 <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]4062 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4063 <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]4064 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4065 <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]4066 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4067 <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]4068 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4069 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4070 <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]4071 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4072 <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]4073 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4074 <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]4075 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4076 <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]4077 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4078 <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]4079 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4080 <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]4081 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4082 <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]4083 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4084</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4085
4086<h5>Example:</h5>
4087<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]4088 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4089 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4090 &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]4091</pre>
4092</div>
4093
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4094<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4095<div class="doc_subsubsection">
4096 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4097</div>
4098<div class="doc_text">
4099<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4100<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]4101</pre>
4102<h5>Overview:</h5>
4103<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4104element-wise comparison of its two integer vector operands.</p>
4105<h5>Arguments:</h5>
4106<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4107the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4108a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4109<ol>
4110 <li><tt>eq</tt>: equal</li>
4111 <li><tt>ne</tt>: not equal </li>
4112 <li><tt>ugt</tt>: unsigned greater than</li>
4113 <li><tt>uge</tt>: unsigned greater or equal</li>
4114 <li><tt>ult</tt>: unsigned less than</li>
4115 <li><tt>ule</tt>: unsigned less or equal</li>
4116 <li><tt>sgt</tt>: signed greater than</li>
4117 <li><tt>sge</tt>: signed greater or equal</li>
4118 <li><tt>slt</tt>: signed less than</li>
4119 <li><tt>sle</tt>: signed less or equal</li>
4120</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4121<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4122<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4123<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4124<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4125according to the condition code given as <tt>cond</tt>. The comparison yields a
4126<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4127identical type as the values being compared. The most significant bit in each
4128element is 1 if the element-wise comparison evaluates to true, and is 0
4129otherwise. All other bits of the result are undefined. The condition codes
4130are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4131instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4132
4133<h5>Example:</h5>
4134<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4135 &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>
4136 &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]4137</pre>
4138</div>
4139
4140<!-- _______________________________________________________________________ -->
4141<div class="doc_subsubsection">
4142 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4143</div>
4144<div class="doc_text">
4145<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4146<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]4147<h5>Overview:</h5>
4148<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4149element-wise comparison of its two floating point vector operands. The output
4150elements have the same width as the input elements.</p>
4151<h5>Arguments:</h5>
4152<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4153the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4154a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4155<ol>
4156 <li><tt>false</tt>: no comparison, always returns false</li>
4157 <li><tt>oeq</tt>: ordered and equal</li>
4158 <li><tt>ogt</tt>: ordered and greater than </li>
4159 <li><tt>oge</tt>: ordered and greater than or equal</li>
4160 <li><tt>olt</tt>: ordered and less than </li>
4161 <li><tt>ole</tt>: ordered and less than or equal</li>
4162 <li><tt>one</tt>: ordered and not equal</li>
4163 <li><tt>ord</tt>: ordered (no nans)</li>
4164 <li><tt>ueq</tt>: unordered or equal</li>
4165 <li><tt>ugt</tt>: unordered or greater than </li>
4166 <li><tt>uge</tt>: unordered or greater than or equal</li>
4167 <li><tt>ult</tt>: unordered or less than </li>
4168 <li><tt>ule</tt>: unordered or less than or equal</li>
4169 <li><tt>une</tt>: unordered or not equal</li>
4170 <li><tt>uno</tt>: unordered (either nans)</li>
4171 <li><tt>true</tt>: no comparison, always returns true</li>
4172</ol>
4173<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4174<a href="#t_floating">floating point</a> typed. They must also be identical
4175types.</p>
4176<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4177<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4178according to the condition code given as <tt>cond</tt>. The comparison yields a
4179<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4180an identical number of elements as the values being compared, and each element
4181having identical with to the width of the floating point elements. The most
4182significant bit in each element is 1 if the element-wise comparison evaluates to
4183true, and is 0 otherwise. All other bits of the result are undefined. The
4184condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4185<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4186
4187<h5>Example:</h5>
4188<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4189 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4190 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4191
4192 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4193 &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]4194</pre>
4195</div>
4196
4197<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4198<div class="doc_subsubsection">
4199 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4200</div>
4201
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4202<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4203
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4204<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4205
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4206<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4207<h5>Overview:</h5>
4208<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4209the SSA graph representing the function.</p>
4210<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4211
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4212<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4213field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4214as arguments, with one pair for each predecessor basic block of the
4215current block. Only values of <a href="#t_firstclass">first class</a>
4216type may be used as the value arguments to the PHI node. Only labels
4217may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4218
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4219<p>There must be no non-phi instructions between the start of a basic
4220block and the PHI instructions: i.e. PHI instructions must be first in
4221a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4222
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4223<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4224
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4225<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4226specified by the pair corresponding to the predecessor basic block that executed
4227just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4228
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4229<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4230<pre>
4231Loop: ; Infinite loop that counts from 0 on up...
4232 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4233 %nextindvar = add i32 %indvar, 1
4234 br label %Loop
4235</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4236</div>
4237
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4238<!-- _______________________________________________________________________ -->
4239<div class="doc_subsubsection">
4240 <a name="i_select">'<tt>select</tt>' Instruction</a>
4241</div>
4242
4243<div class="doc_text">
4244
4245<h5>Syntax:</h5>
4246
4247<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4248 &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>
4249
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4250 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4251</pre>
4252
4253<h5>Overview:</h5>
4254
4255<p>
4256The '<tt>select</tt>' instruction is used to choose one value based on a
4257condition, without branching.
4258</p>
4259
4260
4261<h5>Arguments:</h5>
4262
4263<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4264The '<tt>select</tt>' instruction requires an 'i1' value or
4265a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4266condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4267type. If the val1/val2 are vectors and
4268the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4269individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4270</p>
4271
4272<h5>Semantics:</h5>
4273
4274<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4275If 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]4276value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4277</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4278<p>
4279If the condition is a vector of i1, then the value arguments must
4280be vectors of the same size, and the selection is done element
4281by element.
4282</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4283
4284<h5>Example:</h5>
4285
4286<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4287 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4288</pre>
4289</div>
4290
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4291
4292<!-- _______________________________________________________________________ -->
4293<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4294 <a name="i_call">'<tt>call</tt>' Instruction</a>
4295</div>
4296
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4297<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4298
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4299<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4300<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4301 &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]4302</pre>
4303
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4304<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4305
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4306<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4307
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4308<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4309
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4310<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4311
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4312<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4313 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4314 <p>The optional "tail" marker indicates whether the callee function accesses
4315 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4316 function call is eligible for tail call optimization. Note that calls may
4317 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4318 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4319 </li>
4320 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4321 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4322 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4323 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4324 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4325
4326 <li>
4327 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4328 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4329 and '<tt>inreg</tt>' attributes are valid here.</p>
4330 </li>
4331
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4332 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4333 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4334 the type of the return value. Functions that return no value are marked
4335 <tt><a href="#t_void">void</a></tt>.</p>
4336 </li>
4337 <li>
4338 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4339 value being invoked. The argument types must match the types implied by
4340 this signature. This type can be omitted if the function is not varargs
4341 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4342 </li>
4343 <li>
4344 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4345 be invoked. In most cases, this is a direct function invocation, but
4346 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4347 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4348 </li>
4349 <li>
4350 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4351 function signature argument types. All arguments must be of
4352 <a href="#t_firstclass">first class</a> type. If the function signature
4353 indicates the function accepts a variable number of arguments, the extra
4354 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4355 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4356 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4357 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4358 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4359 '<tt>readnone</tt>' attributes are valid here.</p>
4360 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4361</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4363<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4364
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4365<p>The '<tt>call</tt>' instruction is used to cause control flow to
4366transfer to a specified function, with its incoming arguments bound to
4367the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4368instruction in the called function, control flow continues with the
4369instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4370function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4371
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4372<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4373
4374<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4375 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4376 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4377 %X = tail call i32 @foo() <i>; yields i32</i>
4378 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4379 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4380
4381 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4382 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4383 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4384 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4385 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4386 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4387</pre>
4388
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4389</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4390
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4391<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4392<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4393 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4394</div>
4395
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4396<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4397
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4398<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4399
4400<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4401 &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]4402</pre>
4403
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4404<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4405
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4406<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4407the "variable argument" area of a function call. It is used to implement the
4408<tt>va_arg</tt> macro in C.</p>
4409
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4410<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4411
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4412<p>This instruction takes a <tt>va_list*</tt> value and the type of
4413the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4414increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4415actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4416
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4417<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4418
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4419<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4420type from the specified <tt>va_list</tt> and causes the
4421<tt>va_list</tt> to point to the next argument. For more information,
4422see the variable argument handling <a href="#int_varargs">Intrinsic
4423Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4424
4425<p>It is legal for this instruction to be called in a function which does not
4426take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4427function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4428
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4429<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4430href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4431argument.</p>
4432
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4433<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4434
4435<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4436
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4437</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4438
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4439<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4440<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4441<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4442
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4443<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4444
4445<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4446well known names and semantics and are required to follow certain restrictions.
4447Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4448language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4449adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4450
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4451<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4452prefix is reserved in LLVM for intrinsic names; thus, function names may not
4453begin with this prefix. Intrinsic functions must always be external functions:
4454you cannot define the body of intrinsic functions. Intrinsic functions may
4455only be used in call or invoke instructions: it is illegal to take the address
4456of an intrinsic function. Additionally, because intrinsic functions are part
4457of the LLVM language, it is required if any are added that they be documented
4458here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4459
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4460<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4461a family of functions that perform the same operation but on different data
4462types. Because LLVM can represent over 8 million different integer types,
4463overloading is used commonly to allow an intrinsic function to operate on any
4464integer type. One or more of the argument types or the result type can be
4465overloaded to accept any integer type. Argument types may also be defined as
4466exactly matching a previous argument's type or the result type. This allows an
4467intrinsic function which accepts multiple arguments, but needs all of them to
4468be of the same type, to only be overloaded with respect to a single argument or
4469the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4470
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4471<p>Overloaded intrinsics will have the names of its overloaded argument types
4472encoded into its function name, each preceded by a period. Only those types
4473which are overloaded result in a name suffix. Arguments whose type is matched
4474against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4475take an integer of any width and returns an integer of exactly the same integer
4476width. This leads to a family of functions such as
4477<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4478Only one type, the return type, is overloaded, and only one type suffix is
4479required. Because the argument's type is matched against the return type, it
4480does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4481
4482<p>To learn how to add an intrinsic function, please see the
4483<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4484</p>
4485
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4486</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4487
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4488<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4489<div class="doc_subsection">
4490 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4491</div>
4492
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4493<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4494
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4495<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4496 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4497intrinsic functions. These functions are related to the similarly
4498named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4499
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4500<p>All of these functions operate on arguments that use a
4501target-specific value type "<tt>va_list</tt>". The LLVM assembly
4502language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4503transformations should be prepared to handle these functions regardless of
4504the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4505
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4506<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]4507instruction and the variable argument handling intrinsic functions are
4508used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4509
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4510<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4511<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4512define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4513 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4514 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4515 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4516 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4517
4518 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4519 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4520
4521 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4522 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4523 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4524 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4525 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4526
4527 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4528 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4529 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4530}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4531
4532declare void @llvm.va_start(i8*)
4533declare void @llvm.va_copy(i8*, i8*)
4534declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4535</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4536</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4537
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4538</div>
4539
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4540<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4541<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4542 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4543</div>
4544
4545
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4546<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4547<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4548<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4549<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4550<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4551<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4552href="#i_va_arg">va_arg</a></tt>.</p>
4553
4554<h5>Arguments:</h5>
4555
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4556<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]4557
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4558<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4559
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4560<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]4561macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4562<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]4563<tt>va_arg</tt> will produce the first variable argument passed to the function.
4564Unlike 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]4565last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4566
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4567</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4568
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4569<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4570<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4571 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4572</div>
4573
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4574<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4575<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4576<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4577<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4578
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4579<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4580which 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]4581or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4582
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4583<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4584
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4585<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]4586
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4587<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4588
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4589<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]4590macro available in C. In a target-dependent way, it destroys the
4591<tt>va_list</tt> element to which the argument points. Calls to <a
4592href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4593<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4594<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4595
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4596</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4597
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4598<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4599<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4600 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4601</div>
4602
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4603<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4604
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4605<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4606
4607<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4608 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4609</pre>
4610
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4611<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4612
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4613<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4614from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4615
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4616<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4617
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4618<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]4619The 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]4620
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4621
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4622<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4623
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4624<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4625macro available in C. In a target-dependent way, it copies the source
4626<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4627intrinsic is necessary because the <tt><a href="#int_va_start">
4628llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4629example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4630
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4631</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4632
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4633<!-- ======================================================================= -->
4634<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4635 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4636</div>
4637
4638<div class="doc_text">
4639
4640<p>
4641LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4642Collection</a> (GC) requires the implementation and generation of these
4643intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4644These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4645stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4646href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4647Front-ends for type-safe garbage collected languages should generate these
4648intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4649href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4650</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4651
4652<p>The garbage collection intrinsics only operate on objects in the generic
4653 address space (address space zero).</p>
4654
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4655</div>
4656
4657<!-- _______________________________________________________________________ -->
4658<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4659 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4660</div>
4661
4662<div class="doc_text">
4663
4664<h5>Syntax:</h5>
4665
4666<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4667 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4668</pre>
4669
4670<h5>Overview:</h5>
4671
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4672<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]4673the code generator, and allows some metadata to be associated with it.</p>
4674
4675<h5>Arguments:</h5>
4676
4677<p>The first argument specifies the address of a stack object that contains the
4678root pointer. The second pointer (which must be either a constant or a global
4679value address) contains the meta-data to be associated with the root.</p>
4680
4681<h5>Semantics:</h5>
4682
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4683<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]4684location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4685the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4686intrinsic may only be used in a function which <a href="#gc">specifies a GC
4687algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4688
4689</div>
4690
4691
4692<!-- _______________________________________________________________________ -->
4693<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4694 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4695</div>
4696
4697<div class="doc_text">
4698
4699<h5>Syntax:</h5>
4700
4701<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4702 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4703</pre>
4704
4705<h5>Overview:</h5>
4706
4707<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4708locations, allowing garbage collector implementations that require read
4709barriers.</p>
4710
4711<h5>Arguments:</h5>
4712
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4713<p>The second argument is the address to read from, which should be an address
4714allocated from the garbage collector. The first object is a pointer to the
4715start of the referenced object, if needed by the language runtime (otherwise
4716null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4717
4718<h5>Semantics:</h5>
4719
4720<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4721instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4722garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4723may only be used in a function which <a href="#gc">specifies a GC
4724algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4725
4726</div>
4727
4728
4729<!-- _______________________________________________________________________ -->
4730<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4731 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4732</div>
4733
4734<div class="doc_text">
4735
4736<h5>Syntax:</h5>
4737
4738<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4739 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4740</pre>
4741
4742<h5>Overview:</h5>
4743
4744<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4745locations, allowing garbage collector implementations that require write
4746barriers (such as generational or reference counting collectors).</p>
4747
4748<h5>Arguments:</h5>
4749
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4750<p>The first argument is the reference to store, the second is the start of the
4751object to store it to, and the third is the address of the field of Obj to
4752store to. If the runtime does not require a pointer to the object, Obj may be
4753null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4754
4755<h5>Semantics:</h5>
4756
4757<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4758instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4759garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4760may only be used in a function which <a href="#gc">specifies a GC
4761algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4762
4763</div>
4764
4765
4766
4767<!-- ======================================================================= -->
4768<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4769 <a name="int_codegen">Code Generator Intrinsics</a>
4770</div>
4771
4772<div class="doc_text">
4773<p>
4774These intrinsics are provided by LLVM to expose special features that may only
4775be implemented with code generator support.
4776</p>
4777
4778</div>
4779
4780<!-- _______________________________________________________________________ -->
4781<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4782 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4783</div>
4784
4785<div class="doc_text">
4786
4787<h5>Syntax:</h5>
4788<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4789 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4790</pre>
4791
4792<h5>Overview:</h5>
4793
4794<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4795The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4796target-specific value indicating the return address of the current function
4797or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4798</p>
4799
4800<h5>Arguments:</h5>
4801
4802<p>
4803The argument to this intrinsic indicates which function to return the address
4804for. Zero indicates the calling function, one indicates its caller, etc. The
4805argument is <b>required</b> to be a constant integer value.
4806</p>
4807
4808<h5>Semantics:</h5>
4809
4810<p>
4811The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4812the return address of the specified call frame, or zero if it cannot be
4813identified. The value returned by this intrinsic is likely to be incorrect or 0
4814for arguments other than zero, so it should only be used for debugging purposes.
4815</p>
4816
4817<p>
4818Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4819aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4820source-language caller.
4821</p>
4822</div>
4823
4824
4825<!-- _______________________________________________________________________ -->
4826<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4827 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4828</div>
4829
4830<div class="doc_text">
4831
4832<h5>Syntax:</h5>
4833<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4834 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4835</pre>
4836
4837<h5>Overview:</h5>
4838
4839<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4840The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4841target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4842</p>
4843
4844<h5>Arguments:</h5>
4845
4846<p>
4847The argument to this intrinsic indicates which function to return the frame
4848pointer for. Zero indicates the calling function, one indicates its caller,
4849etc. The argument is <b>required</b> to be a constant integer value.
4850</p>
4851
4852<h5>Semantics:</h5>
4853
4854<p>
4855The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4856the frame address of the specified call frame, or zero if it cannot be
4857identified. The value returned by this intrinsic is likely to be incorrect or 0
4858for arguments other than zero, so it should only be used for debugging purposes.
4859</p>
4860
4861<p>
4862Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4863aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4864source-language caller.
4865</p>
4866</div>
4867
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4868<!-- _______________________________________________________________________ -->
4869<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4870 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4871</div>
4872
4873<div class="doc_text">
4874
4875<h5>Syntax:</h5>
4876<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4877 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4878</pre>
4879
4880<h5>Overview:</h5>
4881
4882<p>
4883The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4884the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4885<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4886features like scoped automatic variable sized arrays in C99.
4887</p>
4888
4889<h5>Semantics:</h5>
4890
4891<p>
4892This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4893href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4894<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4895<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4896state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4897practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4898that were allocated after the <tt>llvm.stacksave</tt> was executed.
4899</p>
4900
4901</div>
4902
4903<!-- _______________________________________________________________________ -->
4904<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4905 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4906</div>
4907
4908<div class="doc_text">
4909
4910<h5>Syntax:</h5>
4911<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4912 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4913</pre>
4914
4915<h5>Overview:</h5>
4916
4917<p>
4918The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4919the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4920href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4921useful for implementing language features like scoped automatic variable sized
4922arrays in C99.
4923</p>
4924
4925<h5>Semantics:</h5>
4926
4927<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4928See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4929</p>
4930
4931</div>
4932
4933
4934<!-- _______________________________________________________________________ -->
4935<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4936 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4937</div>
4938
4939<div class="doc_text">
4940
4941<h5>Syntax:</h5>
4942<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4943 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]4944</pre>
4945
4946<h5>Overview:</h5>
4947
4948
4949<p>
4950The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4951a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4952no
4953effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4954characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4955</p>
4956
4957<h5>Arguments:</h5>
4958
4959<p>
4960<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4961determining if the fetch should be for a read (0) or write (1), and
4962<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4963locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4964<tt>locality</tt> arguments must be constant integers.
4965</p>
4966
4967<h5>Semantics:</h5>
4968
4969<p>
4970This intrinsic does not modify the behavior of the program. In particular,
4971prefetches cannot trap and do not produce a value. On targets that support this
4972intrinsic, the prefetch can provide hints to the processor cache for better
4973performance.
4974</p>
4975
4976</div>
4977
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4978<!-- _______________________________________________________________________ -->
4979<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4980 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4981</div>
4982
4983<div class="doc_text">
4984
4985<h5>Syntax:</h5>
4986<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4987 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4988</pre>
4989
4990<h5>Overview:</h5>
4991
4992
4993<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4994The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4995(PC) in a region of
4996code to simulators and other tools. The method is target specific, but it is
4997expected that the marker will use exported symbols to transmit the PC of the
4998marker.
4999The marker makes no guarantees that it will remain with any specific instruction
5000after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]5001optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5002correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5003</p>
5004
5005<h5>Arguments:</h5>
5006
5007<p>
5008<tt>id</tt> is a numerical id identifying the marker.
5009</p>
5010
5011<h5>Semantics:</h5>
5012
5013<p>
5014This intrinsic does not modify the behavior of the program. Backends that do not
5015support this intrinisic may ignore it.
5016</p>
5017
5018</div>
5019
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5020<!-- _______________________________________________________________________ -->
5021<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5022 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5023</div>
5024
5025<div class="doc_text">
5026
5027<h5>Syntax:</h5>
5028<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5029 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5030</pre>
5031
5032<h5>Overview:</h5>
5033
5034
5035<p>
5036The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5037counter register (or similar low latency, high accuracy clocks) on those targets
5038that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5039As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5040should only be used for small timings.
5041</p>
5042
5043<h5>Semantics:</h5>
5044
5045<p>
5046When directly supported, reading the cycle counter should not modify any memory.
5047Implementations are allowed to either return a application specific value or a
5048system wide value. On backends without support, this is lowered to a constant 0.
5049</p>
5050
5051</div>
5052
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5053<!-- ======================================================================= -->
5054<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5055 <a name="int_libc">Standard C Library Intrinsics</a>
5056</div>
5057
5058<div class="doc_text">
5059<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5060LLVM provides intrinsics for a few important standard C library functions.
5061These intrinsics allow source-language front-ends to pass information about the
5062alignment of the pointer arguments to the code generator, providing opportunity
5063for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5064</p>
5065
5066</div>
5067
5068<!-- _______________________________________________________________________ -->
5069<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5070 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5071</div>
5072
5073<div class="doc_text">
5074
5075<h5>Syntax:</h5>
5076<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5077 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5078 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5079 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5080 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5081</pre>
5082
5083<h5>Overview:</h5>
5084
5085<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5086The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5087location to the destination location.
5088</p>
5089
5090<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5091Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5092intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5093</p>
5094
5095<h5>Arguments:</h5>
5096
5097<p>
5098The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5099the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5100specifying the number of bytes to copy, and the fourth argument is the alignment
5101of the source and destination locations.
5102</p>
5103
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5104<p>
5105If 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]5106the caller guarantees that both the source and destination pointers are aligned
5107to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5108</p>
5109
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5110<h5>Semantics:</h5>
5111
5112<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5113The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5114location to the destination location, which are not allowed to overlap. It
5115copies "len" bytes of memory over. If the argument is known to be aligned to
5116some boundary, this can be specified as the fourth argument, otherwise it should
5117be set to 0 or 1.
5118</p>
5119</div>
5120
5121
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5122<!-- _______________________________________________________________________ -->
5123<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5124 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5125</div>
5126
5127<div class="doc_text">
5128
5129<h5>Syntax:</h5>
5130<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5131 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5132 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5133 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5134 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5135</pre>
5136
5137<h5>Overview:</h5>
5138
5139<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5140The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5141location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5142'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5143</p>
5144
5145<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5146Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5147intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5148</p>
5149
5150<h5>Arguments:</h5>
5151
5152<p>
5153The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5154the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5155specifying the number of bytes to copy, and the fourth argument is the alignment
5156of the source and destination locations.
5157</p>
5158
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5159<p>
5160If 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]5161the caller guarantees that the source and destination pointers are aligned to
5162that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5163</p>
5164
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5165<h5>Semantics:</h5>
5166
5167<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5168The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5169location to the destination location, which may overlap. It
5170copies "len" bytes of memory over. If the argument is known to be aligned to
5171some boundary, this can be specified as the fourth argument, otherwise it should
5172be set to 0 or 1.
5173</p>
5174</div>
5175
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5176
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5177<!-- _______________________________________________________________________ -->
5178<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5179 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5180</div>
5181
5182<div class="doc_text">
5183
5184<h5>Syntax:</h5>
5185<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5186 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5187 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5188 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5189 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5190</pre>
5191
5192<h5>Overview:</h5>
5193
5194<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5195The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5196byte value.
5197</p>
5198
5199<p>
5200Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5201does not return a value, and takes an extra alignment argument.
5202</p>
5203
5204<h5>Arguments:</h5>
5205
5206<p>
5207The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5208byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5209argument specifying the number of bytes to fill, and the fourth argument is the
5210known alignment of destination location.
5211</p>
5212
5213<p>
5214If 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]5215the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5216</p>
5217
5218<h5>Semantics:</h5>
5219
5220<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5221The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5222the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5223destination location. If the argument is known to be aligned to some boundary,
5224this can be specified as the fourth argument, otherwise it should be set to 0 or
52251.
5226</p>
5227</div>
5228
5229
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5230<!-- _______________________________________________________________________ -->
5231<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5232 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5233</div>
5234
5235<div class="doc_text">
5236
5237<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5238<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]5239floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5240types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5241<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5242 declare float @llvm.sqrt.f32(float %Val)
5243 declare double @llvm.sqrt.f64(double %Val)
5244 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5245 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5246 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5247</pre>
5248
5249<h5>Overview:</h5>
5250
5251<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5252The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5253returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5254<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5255negative numbers other than -0.0 (which allows for better optimization, because
5256there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5257defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5258</p>
5259
5260<h5>Arguments:</h5>
5261
5262<p>
5263The argument and return value are floating point numbers of the same type.
5264</p>
5265
5266<h5>Semantics:</h5>
5267
5268<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5269This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5270floating point number.
5271</p>
5272</div>
5273
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5274<!-- _______________________________________________________________________ -->
5275<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5276 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5277</div>
5278
5279<div class="doc_text">
5280
5281<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5282<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]5283floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5284types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5285<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5286 declare float @llvm.powi.f32(float %Val, i32 %power)
5287 declare double @llvm.powi.f64(double %Val, i32 %power)
5288 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5289 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5290 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5291</pre>
5292
5293<h5>Overview:</h5>
5294
5295<p>
5296The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5297specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5298multiplications is not defined. When a vector of floating point type is
5299used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5300</p>
5301
5302<h5>Arguments:</h5>
5303
5304<p>
5305The second argument is an integer power, and the first is a value to raise to
5306that power.
5307</p>
5308
5309<h5>Semantics:</h5>
5310
5311<p>
5312This function returns the first value raised to the second power with an
5313unspecified sequence of rounding operations.</p>
5314</div>
5315
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5316<!-- _______________________________________________________________________ -->
5317<div class="doc_subsubsection">
5318 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5319</div>
5320
5321<div class="doc_text">
5322
5323<h5>Syntax:</h5>
5324<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5325floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5326types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5327<pre>
5328 declare float @llvm.sin.f32(float %Val)
5329 declare double @llvm.sin.f64(double %Val)
5330 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5331 declare fp128 @llvm.sin.f128(fp128 %Val)
5332 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5333</pre>
5334
5335<h5>Overview:</h5>
5336
5337<p>
5338The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5339</p>
5340
5341<h5>Arguments:</h5>
5342
5343<p>
5344The argument and return value are floating point numbers of the same type.
5345</p>
5346
5347<h5>Semantics:</h5>
5348
5349<p>
5350This function returns the sine of the specified operand, returning the
5351same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5352conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5353</div>
5354
5355<!-- _______________________________________________________________________ -->
5356<div class="doc_subsubsection">
5357 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5358</div>
5359
5360<div class="doc_text">
5361
5362<h5>Syntax:</h5>
5363<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5364floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5365types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5366<pre>
5367 declare float @llvm.cos.f32(float %Val)
5368 declare double @llvm.cos.f64(double %Val)
5369 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5370 declare fp128 @llvm.cos.f128(fp128 %Val)
5371 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5372</pre>
5373
5374<h5>Overview:</h5>
5375
5376<p>
5377The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5378</p>
5379
5380<h5>Arguments:</h5>
5381
5382<p>
5383The argument and return value are floating point numbers of the same type.
5384</p>
5385
5386<h5>Semantics:</h5>
5387
5388<p>
5389This function returns the cosine of the specified operand, returning the
5390same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5391conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5392</div>
5393
5394<!-- _______________________________________________________________________ -->
5395<div class="doc_subsubsection">
5396 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5397</div>
5398
5399<div class="doc_text">
5400
5401<h5>Syntax:</h5>
5402<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5403floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5404types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5405<pre>
5406 declare float @llvm.pow.f32(float %Val, float %Power)
5407 declare double @llvm.pow.f64(double %Val, double %Power)
5408 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5409 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5410 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5411</pre>
5412
5413<h5>Overview:</h5>
5414
5415<p>
5416The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5417specified (positive or negative) power.
5418</p>
5419
5420<h5>Arguments:</h5>
5421
5422<p>
5423The second argument is a floating point power, and the first is a value to
5424raise to that power.
5425</p>
5426
5427<h5>Semantics:</h5>
5428
5429<p>
5430This function returns the first value raised to the second power,
5431returning the
5432same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5433conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5434</div>
5435
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5436
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5437<!-- ======================================================================= -->
5438<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5439 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5440</div>
5441
5442<div class="doc_text">
5443<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5444LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5445These allow efficient code generation for some algorithms.
5446</p>
5447
5448</div>
5449
5450<!-- _______________________________________________________________________ -->
5451<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5452 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5453</div>
5454
5455<div class="doc_text">
5456
5457<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5458<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5459type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5460<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5461 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5462 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5463 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5464</pre>
5465
5466<h5>Overview:</h5>
5467
5468<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5469The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5470values with an even number of bytes (positive multiple of 16 bits). These are
5471useful for performing operations on data that is not in the target's native
5472byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5473</p>
5474
5475<h5>Semantics:</h5>
5476
5477<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5478The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5479and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5480intrinsic returns an i32 value that has the four bytes of the input i32
5481swapped, 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]5482i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5483<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5484additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5485</p>
5486
5487</div>
5488
5489<!-- _______________________________________________________________________ -->
5490<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5491 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5492</div>
5493
5494<div class="doc_text">
5495
5496<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5497<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]5498width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5499<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5500 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5501 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5502 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5503 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5504 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5505</pre>
5506
5507<h5>Overview:</h5>
5508
5509<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5510The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5511value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5512</p>
5513
5514<h5>Arguments:</h5>
5515
5516<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5517The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5518integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5519</p>
5520
5521<h5>Semantics:</h5>
5522
5523<p>
5524The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5525</p>
5526</div>
5527
5528<!-- _______________________________________________________________________ -->
5529<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5530 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5531</div>
5532
5533<div class="doc_text">
5534
5535<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5536<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]5537integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5538<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5539 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5540 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5541 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5542 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5543 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5544</pre>
5545
5546<h5>Overview:</h5>
5547
5548<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5549The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5550leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5551</p>
5552
5553<h5>Arguments:</h5>
5554
5555<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5556The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5557integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5558</p>
5559
5560<h5>Semantics:</h5>
5561
5562<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5563The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5564in 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]5565of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5566</p>
5567</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5568
5569
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5570
5571<!-- _______________________________________________________________________ -->
5572<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5573 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5574</div>
5575
5576<div class="doc_text">
5577
5578<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5579<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]5580integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5581<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5582 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5583 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5584 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5585 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5586 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5587</pre>
5588
5589<h5>Overview:</h5>
5590
5591<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5592The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5593trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5594</p>
5595
5596<h5>Arguments:</h5>
5597
5598<p>
5599The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5600integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5601</p>
5602
5603<h5>Semantics:</h5>
5604
5605<p>
5606The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5607in a variable. If the src == 0 then the result is the size in bits of the type
5608of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5609</p>
5610</div>
5611
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5612<!-- _______________________________________________________________________ -->
5613<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5614 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5615</div>
5616
5617<div class="doc_text">
5618
5619<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5620<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5621on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5622<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5623 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5624 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5625</pre>
5626
5627<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5628<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5629range of bits from an integer value and returns them in the same bit width as
5630the original value.</p>
5631
5632<h5>Arguments:</h5>
5633<p>The first argument, <tt>%val</tt> and the result may be integer types of
5634any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5635arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5636
5637<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5638<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5639of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5640<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5641operates in forward mode.</p>
5642<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5643right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5644only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5645<ol>
5646 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5647 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5648 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5649 to determine the number of bits to retain.</li>
5650 <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]5651 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5652</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5653<p>In reverse mode, a similar computation is made except that the bits are
5654returned in the reverse order. So, for example, if <tt>X</tt> has the value
5655<tt>i16 0x0ACF (101011001111)</tt> and we apply
5656<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5657<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5658</div>
5659
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5660<div class="doc_subsubsection">
5661 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5662</div>
5663
5664<div class="doc_text">
5665
5666<h5>Syntax:</h5>
5667<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5668on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5669<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5670 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5671 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]5672</pre>
5673
5674<h5>Overview:</h5>
5675<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5676of bits in an integer value with another integer value. It returns the integer
5677with the replaced bits.</p>
5678
5679<h5>Arguments:</h5>
5680<p>The first argument, <tt>%val</tt> and the result may be integer types of
5681any bit width but they must have the same bit width. <tt>%val</tt> is the value
5682whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5683integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5684type since they specify only a bit index.</p>
5685
5686<h5>Semantics:</h5>
5687<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5688of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5689<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5690operates in forward mode.</p>
5691<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5692truncating it down to the size of the replacement area or zero extending it
5693up to that size.</p>
5694<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5695are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5696in <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]5697to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5698<p>In reverse mode, a similar computation is made except that the bits are
5699reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5700<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]5701<h5>Examples:</h5>
5702<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5703 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5704 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5705 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5706 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5707 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5708</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5709</div>
5710
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5711<!-- ======================================================================= -->
5712<div class="doc_subsection">
5713 <a name="int_debugger">Debugger Intrinsics</a>
5714</div>
5715
5716<div class="doc_text">
5717<p>
5718The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5719are described in the <a
5720href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5721Debugging</a> document.
5722</p>
5723</div>
5724
5725
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5726<!-- ======================================================================= -->
5727<div class="doc_subsection">
5728 <a name="int_eh">Exception Handling Intrinsics</a>
5729</div>
5730
5731<div class="doc_text">
5732<p> The LLVM exception handling intrinsics (which all start with
5733<tt>llvm.eh.</tt> prefix), are described in the <a
5734href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5735Handling</a> document. </p>
5736</div>
5737
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5738<!-- ======================================================================= -->
5739<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5740 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5741</div>
5742
5743<div class="doc_text">
5744<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5745 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5746 the <tt>nest</tt> attribute, from a function. The result is a callable
5747 function pointer lacking the nest parameter - the caller does not need
5748 to provide a value for it. Instead, the value to use is stored in
5749 advance in a "trampoline", a block of memory usually allocated
5750 on the stack, which also contains code to splice the nest value into the
5751 argument list. This is used to implement the GCC nested function address
5752 extension.
5753</p>
5754<p>
5755 For example, if the function is
5756 <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]5757 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]5758<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5759 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5760 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5761 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5762 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5763</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5764 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5765 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5766</div>
5767
5768<!-- _______________________________________________________________________ -->
5769<div class="doc_subsubsection">
5770 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5771</div>
5772<div class="doc_text">
5773<h5>Syntax:</h5>
5774<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5775declare 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]5776</pre>
5777<h5>Overview:</h5>
5778<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5779 This fills the memory pointed to by <tt>tramp</tt> with code
5780 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5781</p>
5782<h5>Arguments:</h5>
5783<p>
5784 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5785 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5786 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5787 intrinsic. Note that the size and the alignment are target-specific - LLVM
5788 currently provides no portable way of determining them, so a front-end that
5789 generates this intrinsic needs to have some target-specific knowledge.
5790 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]5791</p>
5792<h5>Semantics:</h5>
5793<p>
5794 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5795 dependent code, turning it into a function. A pointer to this function is
5796 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5797 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5798 before being called. The new function's signature is the same as that of
5799 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5800 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5801 of pointer type. Calling the new function is equivalent to calling
5802 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5803 missing <tt>nest</tt> argument. If, after calling
5804 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5805 modified, then the effect of any later call to the returned function pointer is
5806 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5807</p>
5808</div>
5809
5810<!-- ======================================================================= -->
5811<div class="doc_subsection">
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame^]5812 <a name="int_stackprotect">Stack Protector Intrinsic</a>
5813</div>
5814
5815<div class="doc_text">
5816<p>
5817 This intrinsic is used when stack protectors are required. LLVM generates a
5818 call to load the randomized stack protector guard's value. The intrinsic is
5819 used so that LLVM can ensure that the stack guard is placed onto the stack in
5820 the appropriate place&mdash;before local variables are allocated on the stack.
5821</p>
5822</div>
5823
5824<!-- _______________________________________________________________________ -->
5825<div class="doc_subsubsection">
5826 <a name="int_ssp">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
5827</div>
5828<div class="doc_text">
5829<h5>Syntax:</h5>
5830<pre>
5831declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
5832
5833</pre>
5834<h5>Overview:</h5>
5835<p>
5836 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
5837 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
5838 it's before local variables are allocated on the stack.
5839</p>
5840<h5>Arguments:</h5>
5841<p>
5842 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
5843 first argument is the value loaded from the stack guard
5844 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
5845 has enough space to hold the value of the guard.
5846</p>
5847<h5>Semantics:</h5>
5848<p>
5849 This intrinsic causes the prologue/epilogue inserter to force the position of
5850 the <tt>AllocaInst</tt> stack slot to be before local variables on the
5851 stack. This is to ensure that if a local variable on the stack is overwritten,
5852 it will destroy the value of the guard. When the function exits, the guard on
5853 the stack is checked against the original guard. If they're different, then
5854 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
5855</p>
5856</div>
5857
5858<!-- ======================================================================= -->
5859<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5860 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5861</div>
5862
5863<div class="doc_text">
5864<p>
5865 These intrinsic functions expand the "universal IR" of LLVM to represent
5866 hardware constructs for atomic operations and memory synchronization. This
5867 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5868 is aimed at a low enough level to allow any programming models or APIs
5869 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5870 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5871 hardware behavior. Just as hardware provides a "universal IR" for source
5872 languages, it also provides a starting point for developing a "universal"
5873 atomic operation and synchronization IR.
5874</p>
5875<p>
5876 These do <em>not</em> form an API such as high-level threading libraries,
5877 software transaction memory systems, atomic primitives, and intrinsic
5878 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5879 application libraries. The hardware interface provided by LLVM should allow
5880 a clean implementation of all of these APIs and parallel programming models.
5881 No one model or paradigm should be selected above others unless the hardware
5882 itself ubiquitously does so.
5883
5884</p>
5885</div>
5886
5887<!-- _______________________________________________________________________ -->
5888<div class="doc_subsubsection">
5889 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5890</div>
5891<div class="doc_text">
5892<h5>Syntax:</h5>
5893<pre>
5894declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5895i1 &lt;device&gt; )
5896
5897</pre>
5898<h5>Overview:</h5>
5899<p>
5900 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5901 specific pairs of memory access types.
5902</p>
5903<h5>Arguments:</h5>
5904<p>
5905 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5906 The first four arguments enables a specific barrier as listed below. The fith
5907 argument specifies that the barrier applies to io or device or uncached memory.
5908
5909</p>
5910 <ul>
5911 <li><tt>ll</tt>: load-load barrier</li>
5912 <li><tt>ls</tt>: load-store barrier</li>
5913 <li><tt>sl</tt>: store-load barrier</li>
5914 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5915 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5916 </ul>
5917<h5>Semantics:</h5>
5918<p>
5919 This intrinsic causes the system to enforce some ordering constraints upon
5920 the loads and stores of the program. This barrier does not indicate
5921 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5922 which they occur. For any of the specified pairs of load and store operations
5923 (f.ex. load-load, or store-load), all of the first operations preceding the
5924 barrier will complete before any of the second operations succeeding the
5925 barrier begin. Specifically the semantics for each pairing is as follows:
5926</p>
5927 <ul>
5928 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5929 after the barrier begins.</li>
5930
5931 <li><tt>ls</tt>: All loads before the barrier must complete before any
5932 store after the barrier begins.</li>
5933 <li><tt>ss</tt>: All stores before the barrier must complete before any
5934 store after the barrier begins.</li>
5935 <li><tt>sl</tt>: All stores before the barrier must complete before any
5936 load after the barrier begins.</li>
5937 </ul>
5938<p>
5939 These semantics are applied with a logical "and" behavior when more than one
5940 is enabled in a single memory barrier intrinsic.
5941</p>
5942<p>
5943 Backends may implement stronger barriers than those requested when they do not
5944 support as fine grained a barrier as requested. Some architectures do not
5945 need all types of barriers and on such architectures, these become noops.
5946</p>
5947<h5>Example:</h5>
5948<pre>
5949%ptr = malloc i32
5950 store i32 4, %ptr
5951
5952%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5953 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5954 <i>; guarantee the above finishes</i>
5955 store i32 8, %ptr <i>; before this begins</i>
5956</pre>
5957</div>
5958
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5959<!-- _______________________________________________________________________ -->
5960<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5961 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5962</div>
5963<div class="doc_text">
5964<h5>Syntax:</h5>
5965<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5966 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5967 any integer bit width and for different address spaces. Not all targets
5968 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5969
5970<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5971declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5972declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5973declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5974declare 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]5975
5976</pre>
5977<h5>Overview:</h5>
5978<p>
5979 This loads a value in memory and compares it to a given value. If they are
5980 equal, it stores a new value into the memory.
5981</p>
5982<h5>Arguments:</h5>
5983<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5984 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5985 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5986 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5987 this integer type. While any bit width integer may be used, targets may only
5988 lower representations they support in hardware.
5989
5990</p>
5991<h5>Semantics:</h5>
5992<p>
5993 This entire intrinsic must be executed atomically. It first loads the value
5994 in memory pointed to by <tt>ptr</tt> and compares it with the value
5995 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5996 loaded value is yielded in all cases. This provides the equivalent of an
5997 atomic compare-and-swap operation within the SSA framework.
5998</p>
5999<h5>Examples:</h5>
6000
6001<pre>
6002%ptr = malloc i32
6003 store i32 4, %ptr
6004
6005%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6006%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6007 <i>; yields {i32}:result1 = 4</i>
6008%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6009%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6010
6011%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6012%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6013 <i>; yields {i32}:result2 = 8</i>
6014%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6015
6016%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6017</pre>
6018</div>
6019
6020<!-- _______________________________________________________________________ -->
6021<div class="doc_subsubsection">
6022 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6023</div>
6024<div class="doc_text">
6025<h5>Syntax:</h5>
6026
6027<p>
6028 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6029 integer bit width. Not all targets support all bit widths however.</p>
6030<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6031declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6032declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6033declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6034declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6035
6036</pre>
6037<h5>Overview:</h5>
6038<p>
6039 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6040 the value from memory. It then stores the value in <tt>val</tt> in the memory
6041 at <tt>ptr</tt>.
6042</p>
6043<h5>Arguments:</h5>
6044
6045<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6046 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6047 <tt>val</tt> argument and the result must be integers of the same bit width.
6048 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6049 integer type. The targets may only lower integer representations they
6050 support.
6051</p>
6052<h5>Semantics:</h5>
6053<p>
6054 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6055 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6056 equivalent of an atomic swap operation within the SSA framework.
6057
6058</p>
6059<h5>Examples:</h5>
6060<pre>
6061%ptr = malloc i32
6062 store i32 4, %ptr
6063
6064%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6065%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6066 <i>; yields {i32}:result1 = 4</i>
6067%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6068%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6069
6070%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6071%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6072 <i>; yields {i32}:result2 = 8</i>
6073
6074%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6075%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6076</pre>
6077</div>
6078
6079<!-- _______________________________________________________________________ -->
6080<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6081 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6082
6083</div>
6084<div class="doc_text">
6085<h5>Syntax:</h5>
6086<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6087 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]6088 integer bit width. Not all targets support all bit widths however.</p>
6089<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6090declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6091declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6092declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6093declare 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]6094
6095</pre>
6096<h5>Overview:</h5>
6097<p>
6098 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6099 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6100</p>
6101<h5>Arguments:</h5>
6102<p>
6103
6104 The intrinsic takes two arguments, the first a pointer to an integer value
6105 and the second an integer value. The result is also an integer value. These
6106 integer types can have any bit width, but they must all have the same bit
6107 width. The targets may only lower integer representations they support.
6108</p>
6109<h5>Semantics:</h5>
6110<p>
6111 This intrinsic does a series of operations atomically. It first loads the
6112 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6113 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6114</p>
6115
6116<h5>Examples:</h5>
6117<pre>
6118%ptr = malloc i32
6119 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6120%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6121 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6122%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6123 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6124%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6125 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6126%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6127</pre>
6128</div>
6129
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6130<!-- _______________________________________________________________________ -->
6131<div class="doc_subsubsection">
6132 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6133
6134</div>
6135<div class="doc_text">
6136<h5>Syntax:</h5>
6137<p>
6138 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]6139 any integer bit width and for different address spaces. Not all targets
6140 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6141<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6142declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6143declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6144declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6145declare 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]6146
6147</pre>
6148<h5>Overview:</h5>
6149<p>
6150 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6151 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6152</p>
6153<h5>Arguments:</h5>
6154<p>
6155
6156 The intrinsic takes two arguments, the first a pointer to an integer value
6157 and the second an integer value. The result is also an integer value. These
6158 integer types can have any bit width, but they must all have the same bit
6159 width. The targets may only lower integer representations they support.
6160</p>
6161<h5>Semantics:</h5>
6162<p>
6163 This intrinsic does a series of operations atomically. It first loads the
6164 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6165 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6166</p>
6167
6168<h5>Examples:</h5>
6169<pre>
6170%ptr = malloc i32
6171 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6172%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6173 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6174%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6175 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6176%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6177 <i>; yields {i32}:result3 = 2</i>
6178%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6179</pre>
6180</div>
6181
6182<!-- _______________________________________________________________________ -->
6183<div class="doc_subsubsection">
6184 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6185 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6186 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6187 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6188
6189</div>
6190<div class="doc_text">
6191<h5>Syntax:</h5>
6192<p>
6193 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6194 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6195 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6196 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6197<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6198declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6199declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6200declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6201declare 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]6202
6203</pre>
6204
6205<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6206declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6207declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6208declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6209declare 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]6210
6211</pre>
6212
6213<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6214declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6215declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6216declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6217declare 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]6218
6219</pre>
6220
6221<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6222declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6223declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6224declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6225declare 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]6226
6227</pre>
6228<h5>Overview:</h5>
6229<p>
6230 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6231 the value stored in memory at <tt>ptr</tt>. It yields the original value
6232 at <tt>ptr</tt>.
6233</p>
6234<h5>Arguments:</h5>
6235<p>
6236
6237 These intrinsics take two arguments, the first a pointer to an integer value
6238 and the second an integer value. The result is also an integer value. These
6239 integer types can have any bit width, but they must all have the same bit
6240 width. The targets may only lower integer representations they support.
6241</p>
6242<h5>Semantics:</h5>
6243<p>
6244 These intrinsics does a series of operations atomically. They first load the
6245 value stored at <tt>ptr</tt>. They then do the bitwise operation
6246 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6247 value stored at <tt>ptr</tt>.
6248</p>
6249
6250<h5>Examples:</h5>
6251<pre>
6252%ptr = malloc i32
6253 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6254%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6255 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6256%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6257 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6258%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6259 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6260%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6261 <i>; yields {i32}:result3 = FF</i>
6262%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6263</pre>
6264</div>
6265
6266
6267<!-- _______________________________________________________________________ -->
6268<div class="doc_subsubsection">
6269 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6270 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6271 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6272 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6273
6274</div>
6275<div class="doc_text">
6276<h5>Syntax:</h5>
6277<p>
6278 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6279 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6280 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6281 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6282 support all bit widths however.</p>
6283<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6284declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6285declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6286declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6287declare 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]6288
6289</pre>
6290
6291<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6292declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6293declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6294declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6295declare 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]6296
6297</pre>
6298
6299<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6300declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6301declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6302declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6303declare 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]6304
6305</pre>
6306
6307<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6308declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6309declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6310declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6311declare 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]6312
6313</pre>
6314<h5>Overview:</h5>
6315<p>
6316 These intrinsics takes the signed or unsigned minimum or maximum of
6317 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6318 original value at <tt>ptr</tt>.
6319</p>
6320<h5>Arguments:</h5>
6321<p>
6322
6323 These intrinsics take two arguments, the first a pointer to an integer value
6324 and the second an integer value. The result is also an integer value. These
6325 integer types can have any bit width, but they must all have the same bit
6326 width. The targets may only lower integer representations they support.
6327</p>
6328<h5>Semantics:</h5>
6329<p>
6330 These intrinsics does a series of operations atomically. They first load the
6331 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6332 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6333 the original value stored at <tt>ptr</tt>.
6334</p>
6335
6336<h5>Examples:</h5>
6337<pre>
6338%ptr = malloc i32
6339 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6340%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6341 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6342%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6343 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6344%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6345 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6346%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6347 <i>; yields {i32}:result3 = 8</i>
6348%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6349</pre>
6350</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6351
6352<!-- ======================================================================= -->
6353<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6354 <a name="int_general">General Intrinsics</a>
6355</div>
6356
6357<div class="doc_text">
6358<p> This class of intrinsics is designed to be generic and has
6359no specific purpose. </p>
6360</div>
6361
6362<!-- _______________________________________________________________________ -->
6363<div class="doc_subsubsection">
6364 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6365</div>
6366
6367<div class="doc_text">
6368
6369<h5>Syntax:</h5>
6370<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6371 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]6372</pre>
6373
6374<h5>Overview:</h5>
6375
6376<p>
6377The '<tt>llvm.var.annotation</tt>' intrinsic
6378</p>
6379
6380<h5>Arguments:</h5>
6381
6382<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6383The first argument is a pointer to a value, the second is a pointer to a
6384global string, the third is a pointer to a global string which is the source
6385file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6386</p>
6387
6388<h5>Semantics:</h5>
6389
6390<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6391This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6392This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6393annotations. These have no other defined use, they are ignored by code
6394generation and optimization.
6395</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6396</div>
6397
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6398<!-- _______________________________________________________________________ -->
6399<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6400 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6401</div>
6402
6403<div class="doc_text">
6404
6405<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6406<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6407any integer bit width.
6408</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6409<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6410 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6411 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6412 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6413 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6414 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]6415</pre>
6416
6417<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6418
6419<p>
6420The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6421</p>
6422
6423<h5>Arguments:</h5>
6424
6425<p>
6426The first argument is an integer value (result of some expression),
6427the second is a pointer to a global string, the third is a pointer to a global
6428string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6429It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6430</p>
6431
6432<h5>Semantics:</h5>
6433
6434<p>
6435This intrinsic allows annotations to be put on arbitrary expressions
6436with arbitrary strings. This can be useful for special purpose optimizations
6437that want to look for these annotations. These have no other defined use, they
6438are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6439</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6440</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6441
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6442<!-- _______________________________________________________________________ -->
6443<div class="doc_subsubsection">
6444 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6445</div>
6446
6447<div class="doc_text">
6448
6449<h5>Syntax:</h5>
6450<pre>
6451 declare void @llvm.trap()
6452</pre>
6453
6454<h5>Overview:</h5>
6455
6456<p>
6457The '<tt>llvm.trap</tt>' intrinsic
6458</p>
6459
6460<h5>Arguments:</h5>
6461
6462<p>
6463None
6464</p>
6465
6466<h5>Semantics:</h5>
6467
6468<p>
6469This intrinsics is lowered to the target dependent trap instruction. If the
6470target does not have a trap instruction, this intrinsic will be lowered to the
6471call of the abort() function.
6472</p>
6473</div>
6474
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6475<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6476<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6477<address>
6478 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6479 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6480 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6481 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6482
6483 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6484 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6485 Last modified: $Date$
6486</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6487
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6488</body>
6489</html>