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gerrit-public.fairphone.software / toolchain / llvm-project / ef9462f67c69154e02e7ac2c6e1c58dbe30734b1 / . / 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>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]217 <li><a href="#int_atomics">Atomic intrinsics</a>
218 <ol>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]219 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]220 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]221 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]222 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
223 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
224 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
225 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
226 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
227 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
228 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
229 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
230 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
231 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]232 </ol>
233 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]234 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]235 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]236 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]237 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]238 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]239 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]240 <li><a href="#int_trap">
241 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]242 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]243 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]244 </ol>
245 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]246</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]247
248<div class="doc_author">
249 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
250 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]251</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]252
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]253<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]254<div class="doc_section"> <a name="abstract">Abstract </a></div>
255<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]256
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]257<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]258<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]259LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]260type safety, low-level operations, flexibility, and the capability of
261representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]262representation used throughout all phases of the LLVM compilation
263strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]264</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]265
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]266<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]267<div class="doc_section"> <a name="introduction">Introduction</a> </div>
268<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]269
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]270<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]271
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]272<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]273different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]274representation (suitable for fast loading by a Just-In-Time compiler),
275and as a human readable assembly language representation. This allows
276LLVM to provide a powerful intermediate representation for efficient
277compiler transformations and analysis, while providing a natural means
278to debug and visualize the transformations. The three different forms
279of LLVM are all equivalent. This document describes the human readable
280representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]281
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]282<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]283while being expressive, typed, and extensible at the same time. It
284aims to be a "universal IR" of sorts, by being at a low enough level
285that high-level ideas may be cleanly mapped to it (similar to how
286microprocessors are "universal IR's", allowing many source languages to
287be mapped to them). By providing type information, LLVM can be used as
288the target of optimizations: for example, through pointer analysis, it
289can be proven that a C automatic variable is never accessed outside of
290the current function... allowing it to be promoted to a simple SSA
291value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]292
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]293</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]294
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]295<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]296<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]297
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]298<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]299
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]300<p>It is important to note that this document describes 'well formed'
301LLVM assembly language. There is a difference between what the parser
302accepts and what is considered 'well formed'. For example, the
303following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]304
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]305<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]306<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]307%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]308</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]309</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]311<p>...because the definition of <tt>%x</tt> does not dominate all of
312its uses. The LLVM infrastructure provides a verification pass that may
313be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]314automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]315the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]316by the verifier pass indicate bugs in transformation passes or input to
317the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]318</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]319
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]320<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]322<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]323<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]324<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]326<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]327
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]328 <p>LLVM identifiers come in two basic types: global and local. Global
329 identifiers (functions, global variables) begin with the @ character. Local
330 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]331 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]332
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]333<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]334 <li>Named values are represented as a string of characters with their prefix.
335 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
336 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]337 Identifiers which require other characters in their names can be surrounded
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]338 with quotes. In this way, anything except a <tt>&quot;</tt> character can
339 be used in a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]340
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]341 <li>Unnamed values are represented as an unsigned numeric value with their
342 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]343
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]344 <li>Constants, which are described in a <a href="#constants">section about
345 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]346</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]347
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]348<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]349don't need to worry about name clashes with reserved words, and the set of
350reserved words may be expanded in the future without penalty. Additionally,
351unnamed identifiers allow a compiler to quickly come up with a temporary
352variable without having to avoid symbol table conflicts.</p>
353
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]354<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]355languages. There are keywords for different opcodes
356('<tt><a href="#i_add">add</a></tt>',
357 '<tt><a href="#i_bitcast">bitcast</a></tt>',
358 '<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]359href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]360and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]361none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]362
363<p>Here is an example of LLVM code to multiply the integer variable
364'<tt>%X</tt>' by 8:</p>
365
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]366<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]367
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]368<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]369<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]370%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]371</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]372</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]373
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]374<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]375
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]376<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]377<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]378%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]379</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]380</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]381
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]382<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]383
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]384<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]385<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]386<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
387<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
388%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]389</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]390</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]391
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]392<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
393important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]394
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]395<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]396
397 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
398 line.</li>
399
400 <li>Unnamed temporaries are created when the result of a computation is not
401 assigned to a named value.</li>
402
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]403 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]404
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]405</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]406
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]407<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]408demonstrating instructions, we will follow an instruction with a comment that
409defines the type and name of value produced. Comments are shown in italic
410text.</p>
411
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]412</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]413
414<!-- *********************************************************************** -->
415<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
416<!-- *********************************************************************** -->
417
418<!-- ======================================================================= -->
419<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
420</div>
421
422<div class="doc_text">
423
424<p>LLVM programs are composed of "Module"s, each of which is a
425translation unit of the input programs. Each module consists of
426functions, global variables, and symbol table entries. Modules may be
427combined together with the LLVM linker, which merges function (and
428global variable) definitions, resolves forward declarations, and merges
429symbol table entries. Here is an example of the "hello world" module:</p>
430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]432<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]433<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
434 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]435
436<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]437<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]438
439<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]440define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]441 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]442 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]443 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]444
445 <i>; Call puts function to write out the string to stdout...</i>
446 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]447 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]448 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]449 href="#i_ret">ret</a> i32 0<br>}<br>
450</pre>
451</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]452
453<p>This example is made up of a <a href="#globalvars">global variable</a>
454named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
455function, and a <a href="#functionstructure">function definition</a>
456for "<tt>main</tt>".</p>
457
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458<p>In general, a module is made up of a list of global values,
459where both functions and global variables are global values. Global values are
460represented by a pointer to a memory location (in this case, a pointer to an
461array of char, and a pointer to a function), and have one of the following <a
462href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]463
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464</div>
465
466<!-- ======================================================================= -->
467<div class="doc_subsection">
468 <a name="linkage">Linkage Types</a>
469</div>
470
471<div class="doc_text">
472
473<p>
474All Global Variables and Functions have one of the following types of linkage:
475</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]476
477<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]479 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]480
481 <dd>Global values with internal linkage are only directly accessible by
482 objects in the current module. In particular, linking code into a module with
483 an internal global value may cause the internal to be renamed as necessary to
484 avoid collisions. Because the symbol is internal to the module, all
485 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]486 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]487 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]488
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]490
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]491 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
492 the same name when linkage occurs. This is typically used to implement
493 inline functions, templates, or other code which must be generated in each
494 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
495 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]497
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]498 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
499
500 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
501 linkage, except that unreferenced <tt>common</tt> globals may not be
502 discarded. This is used for globals that may be emitted in multiple
503 translation units, but that are not guaranteed to be emitted into every
504 translation unit that uses them. One example of this is tentative
505 definitions in C, such as "<tt>int X;</tt>" at global scope.
506 </dd>
507
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]508 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]509
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]510 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
511 that some targets may choose to emit different assembly sequences for them
512 for target-dependent reasons. This is used for globals that are declared
513 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]514 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]515
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]516 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]517
518 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
519 pointer to array type. When two global variables with appending linkage are
520 linked together, the two global arrays are appended together. This is the
521 LLVM, typesafe, equivalent of having the system linker append together
522 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]523 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]524
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]525 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]526 <dd>The semantics of this linkage follow the ELF object file model: the
527 symbol is weak until linked, if not linked, the symbol becomes null instead
528 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]529 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]530
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]531 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]532
533 <dd>If none of the above identifiers are used, the global is externally
534 visible, meaning that it participates in linkage and can be used to resolve
535 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]536 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]537</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]538
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]539 <p>
540 The next two types of linkage are targeted for Microsoft Windows platform
541 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]542 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]543 </p>
544
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]545 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
547
548 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
549 or variable via a global pointer to a pointer that is set up by the DLL
550 exporting the symbol. On Microsoft Windows targets, the pointer name is
551 formed by combining <code>_imp__</code> and the function or variable name.
552 </dd>
553
554 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
555
556 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
557 pointer to a pointer in a DLL, so that it can be referenced with the
558 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
559 name is formed by combining <code>_imp__</code> and the function or variable
560 name.
561 </dd>
562
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]563</dl>
564
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]565<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]566variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
567variable and was linked with this one, one of the two would be renamed,
568preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
569external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]570outside of the current module.</p>
571<p>It is illegal for a function <i>declaration</i>
572to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]573or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]574<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^]575linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]576</div>
577
578<!-- ======================================================================= -->
579<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]580 <a name="callingconv">Calling Conventions</a>
581</div>
582
583<div class="doc_text">
584
585<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
586and <a href="#i_invoke">invokes</a> can all have an optional calling convention
587specified for the call. The calling convention of any pair of dynamic
588caller/callee must match, or the behavior of the program is undefined. The
589following calling conventions are supported by LLVM, and more may be added in
590the future:</p>
591
592<dl>
593 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
594
595 <dd>This calling convention (the default if no other calling convention is
596 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]597 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]598 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]599 </dd>
600
601 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
602
603 <dd>This calling convention attempts to make calls as fast as possible
604 (e.g. by passing things in registers). This calling convention allows the
605 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]606 without having to conform to an externally specified ABI (Application Binary
607 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]608 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
609 supported. This calling convention does not support varargs and requires the
610 prototype of all callees to exactly match the prototype of the function
611 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]612 </dd>
613
614 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
615
616 <dd>This calling convention attempts to make code in the caller as efficient
617 as possible under the assumption that the call is not commonly executed. As
618 such, these calls often preserve all registers so that the call does not break
619 any live ranges in the caller side. This calling convention does not support
620 varargs and requires the prototype of all callees to exactly match the
621 prototype of the function definition.
622 </dd>
623
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]624 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]625
626 <dd>Any calling convention may be specified by number, allowing
627 target-specific calling conventions to be used. Target specific calling
628 conventions start at 64.
629 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]630</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]631
632<p>More calling conventions can be added/defined on an as-needed basis, to
633support pascal conventions or any other well-known target-independent
634convention.</p>
635
636</div>
637
638<!-- ======================================================================= -->
639<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]640 <a name="visibility">Visibility Styles</a>
641</div>
642
643<div class="doc_text">
644
645<p>
646All Global Variables and Functions have one of the following visibility styles:
647</p>
648
649<dl>
650 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
651
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]652 <dd>On targets that use the ELF object file format, default visibility means
653 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]654 modules and, in shared libraries, means that the declared entity may be
655 overridden. On Darwin, default visibility means that the declaration is
656 visible to other modules. Default visibility corresponds to "external
657 linkage" in the language.
658 </dd>
659
660 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
661
662 <dd>Two declarations of an object with hidden visibility refer to the same
663 object if they are in the same shared object. Usually, hidden visibility
664 indicates that the symbol will not be placed into the dynamic symbol table,
665 so no other module (executable or shared library) can reference it
666 directly.
667 </dd>
668
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]669 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
670
671 <dd>On ELF, protected visibility indicates that the symbol will be placed in
672 the dynamic symbol table, but that references within the defining module will
673 bind to the local symbol. That is, the symbol cannot be overridden by another
674 module.
675 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]676</dl>
677
678</div>
679
680<!-- ======================================================================= -->
681<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]682 <a name="globalvars">Global Variables</a>
683</div>
684
685<div class="doc_text">
686
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]687<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]688instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]689an explicit section to be placed in, and may have an optional explicit alignment
690specified. A variable may be defined as "thread_local", which means that it
691will not be shared by threads (each thread will have a separated copy of the
692variable). A variable may be defined as a global "constant," which indicates
693that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]694optimization, allowing the global data to be placed in the read-only section of
695an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]696cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]697
698<p>
699LLVM explicitly allows <em>declarations</em> of global variables to be marked
700constant, even if the final definition of the global is not. This capability
701can be used to enable slightly better optimization of the program, but requires
702the language definition to guarantee that optimizations based on the
703'constantness' are valid for the translation units that do not include the
704definition.
705</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]706
707<p>As SSA values, global variables define pointer values that are in
708scope (i.e. they dominate) all basic blocks in the program. Global
709variables always define a pointer to their "content" type because they
710describe a region of memory, and all memory objects in LLVM are
711accessed through pointers.</p>
712
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]713<p>A global variable may be declared to reside in a target-specifc numbered
714address space. For targets that support them, address spaces may affect how
715optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]716the variable. The default address space is zero. The address space qualifier
717must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]718
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]719<p>LLVM allows an explicit section to be specified for globals. If the target
720supports it, it will emit globals to the section specified.</p>
721
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]722<p>An explicit alignment may be specified for a global. If not present, or if
723the alignment is set to zero, the alignment of the global is set by the target
724to whatever it feels convenient. If an explicit alignment is specified, the
725global is forced to have at least that much alignment. All alignments must be
726a power of 2.</p>
727
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]728<p>For example, the following defines a global in a numbered address space with
729an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]730
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]731<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]732<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]733@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]734</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]735</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]736
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]737</div>
738
739
740<!-- ======================================================================= -->
741<div class="doc_subsection">
742 <a name="functionstructure">Functions</a>
743</div>
744
745<div class="doc_text">
746
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]747<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
748an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]749<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]750<a href="#callingconv">calling convention</a>, a return type, an optional
751<a href="#paramattrs">parameter attribute</a> for the return type, a function
752name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]753<a href="#paramattrs">parameter attributes</a>), optional
754<a href="#fnattrs">function attributes</a>, an optional section,
755an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]756an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]757
758LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
759optional <a href="#linkage">linkage type</a>, an optional
760<a href="#visibility">visibility style</a>, an optional
761<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]762<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]763name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]764<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]765
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]766<p>A function definition contains a list of basic blocks, forming the CFG
767(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]768the function. Each basic block may optionally start with a label (giving the
769basic block a symbol table entry), contains a list of instructions, and ends
770with a <a href="#terminators">terminator</a> instruction (such as a branch or
771function return).</p>
772
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]773<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]774executed on entrance to the function, and it is not allowed to have predecessor
775basic blocks (i.e. there can not be any branches to the entry block of a
776function). Because the block can have no predecessors, it also cannot have any
777<a href="#i_phi">PHI nodes</a>.</p>
778
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]779<p>LLVM allows an explicit section to be specified for functions. If the target
780supports it, it will emit functions to the section specified.</p>
781
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]782<p>An explicit alignment may be specified for a function. If not present, or if
783the alignment is set to zero, the alignment of the function is set by the target
784to whatever it feels convenient. If an explicit alignment is specified, the
785function is forced to have at least that much alignment. All alignments must be
786a power of 2.</p>
787
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]788 <h5>Syntax:</h5>
789
790<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]791<tt>
792define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
793 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
794 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
795 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
796 [<a href="#gc">gc</a>] { ... }
797</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]798</div>
799
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]800</div>
801
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]802
803<!-- ======================================================================= -->
804<div class="doc_subsection">
805 <a name="aliasstructure">Aliases</a>
806</div>
807<div class="doc_text">
808 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]809 function, global variable, another alias or bitcast of global value). Aliases
810 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]811 optional <a href="#visibility">visibility style</a>.</p>
812
813 <h5>Syntax:</h5>
814
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]815<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]816<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]817@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]818</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]819</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]820
821</div>
822
823
824
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]825<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]826<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
827<div class="doc_text">
828 <p>The return type and each parameter of a function type may have a set of
829 <i>parameter attributes</i> associated with them. Parameter attributes are
830 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]831 a function. Parameter attributes are considered to be part of the function,
832 not of the function type, so functions with different parameter attributes
833 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]834
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]835 <p>Parameter attributes are simple keywords that follow the type specified. If
836 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]837 example:</p>
838
839<div class="doc_code">
840<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]841declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]842declare i32 @atoi(i8 zeroext)
843declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]844</pre>
845</div>
846
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]847 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
848 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]849
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]850 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]851 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]852 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]853 <dd>This indicates to the code generator that the parameter or return value
854 should be zero-extended to a 32-bit value by the caller (for a parameter)
855 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]856
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]857 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]858 <dd>This indicates to the code generator that the parameter or return value
859 should be sign-extended to a 32-bit value by the caller (for a parameter)
860 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]861
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]862 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]863 <dd>This indicates that this parameter or return value should be treated
864 in a special target-dependent fashion during while emitting code for a
865 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]866 to memory, though some targets use it to distinguish between two different
867 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]868
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]869 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]870 <dd>This indicates that the pointer parameter should really be passed by
871 value to the function. The attribute implies that a hidden copy of the
872 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]873 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]874 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]875 value, but is also valid on pointers to scalars. The copy is considered to
876 belong to the caller not the callee (for example,
877 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]878 <tt>byval</tt> parameters). This is not a valid attribute for return
879 values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]880
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]881 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]882 <dd>This indicates that the pointer parameter specifies the address of a
883 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]884 This pointer must be guaranteed by the caller to be valid: loads and stores
885 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]886 be applied to the first parameter. This is not a valid attribute for
887 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]888
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]889 <dt><tt>noalias</tt></dt>
Owen Anderson61101282008-02-18 04:09:01 +0000[diff] [blame]890 <dd>This indicates that the parameter does not alias any global or any other
891 parameter. The caller is responsible for ensuring that this is the case,
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]892 usually by placing the value in a stack allocation. This is not a valid
893 attribute for return values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]894
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]895 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]896 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]897 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
898 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]899 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]900
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]901</div>
902
903<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]904<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]905 <a name="gc">Garbage Collector Names</a>
906</div>
907
908<div class="doc_text">
909<p>Each function may specify a garbage collector name, which is simply a
910string.</p>
911
912<div class="doc_code"><pre
913>define void @f() gc "name" { ...</pre></div>
914
915<p>The compiler declares the supported values of <i>name</i>. Specifying a
916collector which will cause the compiler to alter its output in order to support
917the named garbage collection algorithm.</p>
918</div>
919
920<!-- ======================================================================= -->
921<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]922 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]923</div>
924
925<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]926
927<p>Function attributes are set to communicate additional information about
928 a function. Function attributes are considered to be part of the function,
929 not of the function type, so functions with different parameter attributes
930 can have the same function type.</p>
931
932 <p>Function attributes are simple keywords that follow the type specified. If
933 multiple attributes are needed, they are space separated. For
934 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]935
936<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]937<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]938define void @f() noinline { ... }
939define void @f() alwaysinline { ... }
940define void @f() alwaysinline optsize { ... }
941define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]942</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]943</div>
944
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]945<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]946<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]947<dd>This attribute indicates that the inliner should attempt to inline this
948function into callers whenever possible, ignoring any active inlining size
949threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]950
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]951<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]952<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]953in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]954<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]955
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]956<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]957<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]958make choices that keep the code size of this function low, and otherwise do
959optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]960
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]961<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]962<dd>This function attribute indicates that the function never returns normally.
963This produces undefined behavior at runtime if the function ever does
964dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]965
966<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]967<dd>This function attribute indicates that the function never returns with an
968unwind or exceptional control flow. If the function does unwind, its runtime
969behavior is undefined.</dd>
970
971<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]972<dd>This attribute indicates that the function computes its result (or the
973exception it throws) based strictly on its arguments, without dereferencing any
974pointer arguments or otherwise accessing any mutable state (e.g. memory, control
975registers, etc) visible to caller functions. It does not write through any
976pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
977never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]978
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]979<dt><tt><a name="readonly">readonly</a></tt></dt>
980<dd>This attribute indicates that the function does not write through any
981pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
982or otherwise modify any state (e.g. memory, control registers, etc) visible to
983caller functions. It may dereference pointer arguments and read state that may
984be set in the caller. A readonly function always returns the same value (or
985throws the same exception) when called with the same set of arguments and global
986state.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]987</dl>
988
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]989</div>
990
991<!-- ======================================================================= -->
992<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]993 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]994</div>
995
996<div class="doc_text">
997<p>
998Modules may contain "module-level inline asm" blocks, which corresponds to the
999GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1000LLVM and treated as a single unit, but may be separated in the .ll file if
1001desired. The syntax is very simple:
1002</p>
1003
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1004<div class="doc_code">
1005<pre>
1006module asm "inline asm code goes here"
1007module asm "more can go here"
1008</pre>
1009</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1010
1011<p>The strings can contain any character by escaping non-printable characters.
1012 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1013 for the number.
1014</p>
1015
1016<p>
1017 The inline asm code is simply printed to the machine code .s file when
1018 assembly code is generated.
1019</p>
1020</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1021
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1022<!-- ======================================================================= -->
1023<div class="doc_subsection">
1024 <a name="datalayout">Data Layout</a>
1025</div>
1026
1027<div class="doc_text">
1028<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1029data is to be laid out in memory. The syntax for the data layout is simply:</p>
1030<pre> target datalayout = "<i>layout specification</i>"</pre>
1031<p>The <i>layout specification</i> consists of a list of specifications
1032separated by the minus sign character ('-'). Each specification starts with a
1033letter and may include other information after the letter to define some
1034aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1035<dl>
1036 <dt><tt>E</tt></dt>
1037 <dd>Specifies that the target lays out data in big-endian form. That is, the
1038 bits with the most significance have the lowest address location.</dd>
1039 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1040 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1041 the bits with the least significance have the lowest address location.</dd>
1042 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1043 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1044 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1045 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1046 too.</dd>
1047 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1048 <dd>This specifies the alignment for an integer type of a given bit
1049 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1050 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1051 <dd>This specifies the alignment for a vector type of a given bit
1052 <i>size</i>.</dd>
1053 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1054 <dd>This specifies the alignment for a floating point type of a given bit
1055 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1056 (double).</dd>
1057 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1058 <dd>This specifies the alignment for an aggregate type of a given bit
1059 <i>size</i>.</dd>
1060</dl>
1061<p>When constructing the data layout for a given target, LLVM starts with a
1062default set of specifications which are then (possibly) overriden by the
1063specifications in the <tt>datalayout</tt> keyword. The default specifications
1064are given in this list:</p>
1065<ul>
1066 <li><tt>E</tt> - big endian</li>
1067 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1068 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1069 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1070 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1071 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1072 <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]1073 alignment of 64-bits</li>
1074 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1075 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1076 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1077 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1078 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1079</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1080<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]1081following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1082<ol>
1083 <li>If the type sought is an exact match for one of the specifications, that
1084 specification is used.</li>
1085 <li>If no match is found, and the type sought is an integer type, then the
1086 smallest integer type that is larger than the bitwidth of the sought type is
1087 used. If none of the specifications are larger than the bitwidth then the the
1088 largest integer type is used. For example, given the default specifications
1089 above, the i7 type will use the alignment of i8 (next largest) while both
1090 i65 and i256 will use the alignment of i64 (largest specified).</li>
1091 <li>If no match is found, and the type sought is a vector type, then the
1092 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]1093 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1094 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1095</ol>
1096</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1097
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1098<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1099<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1100<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1101
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1102<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1103
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1104<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1105intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1106optimizations to be performed on the intermediate representation directly,
1107without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1108extra analyses on the side before the transformation. A strong type
1109system makes it easier to read the generated code and enables novel
1110analyses and transformations that are not feasible to perform on normal
1111three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1112
1113</div>
1114
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1115<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1116<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1117Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1118<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1119<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1120classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1121
1122<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1123 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1124 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1125 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1126 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1127 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1128 </tr>
1129 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1130 <td><a href="#t_floating">floating point</a></td>
1131 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1132 </tr>
1133 <tr>
1134 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1135 <td><a href="#t_integer">integer</a>,
1136 <a href="#t_floating">floating point</a>,
1137 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1138 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1139 <a href="#t_struct">structure</a>,
1140 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1141 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1142 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1143 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1144 <tr>
1145 <td><a href="#t_primitive">primitive</a></td>
1146 <td><a href="#t_label">label</a>,
1147 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1148 <a href="#t_floating">floating point</a>.</td>
1149 </tr>
1150 <tr>
1151 <td><a href="#t_derived">derived</a></td>
1152 <td><a href="#t_integer">integer</a>,
1153 <a href="#t_array">array</a>,
1154 <a href="#t_function">function</a>,
1155 <a href="#t_pointer">pointer</a>,
1156 <a href="#t_struct">structure</a>,
1157 <a href="#t_pstruct">packed structure</a>,
1158 <a href="#t_vector">vector</a>,
1159 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1160 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1161 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1162 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1163</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1164
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1165<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1166most important. Values of these types are the only ones which can be
1167produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1168instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1169</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1170
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1171<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1172<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1173
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1174<div class="doc_text">
1175<p>The primitive types are the fundamental building blocks of the LLVM
1176system.</p>
1177
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1178</div>
1179
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1180<!-- _______________________________________________________________________ -->
1181<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1182
1183<div class="doc_text">
1184 <table>
1185 <tbody>
1186 <tr><th>Type</th><th>Description</th></tr>
1187 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1188 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1189 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1190 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1191 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1192 </tbody>
1193 </table>
1194</div>
1195
1196<!-- _______________________________________________________________________ -->
1197<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1198
1199<div class="doc_text">
1200<h5>Overview:</h5>
1201<p>The void type does not represent any value and has no size.</p>
1202
1203<h5>Syntax:</h5>
1204
1205<pre>
1206 void
1207</pre>
1208</div>
1209
1210<!-- _______________________________________________________________________ -->
1211<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1212
1213<div class="doc_text">
1214<h5>Overview:</h5>
1215<p>The label type represents code labels.</p>
1216
1217<h5>Syntax:</h5>
1218
1219<pre>
1220 label
1221</pre>
1222</div>
1223
1224
1225<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1226<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1227
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1228<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1229
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1230<p>The real power in LLVM comes from the derived types in the system.
1231This is what allows a programmer to represent arrays, functions,
1232pointers, and other useful types. Note that these derived types may be
1233recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1234
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1235</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1236
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1237<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1238<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1239
1240<div class="doc_text">
1241
1242<h5>Overview:</h5>
1243<p>The integer type is a very simple derived type that simply specifies an
1244arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12452^23-1 (about 8 million) can be specified.</p>
1246
1247<h5>Syntax:</h5>
1248
1249<pre>
1250 iN
1251</pre>
1252
1253<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1254value.</p>
1255
1256<h5>Examples:</h5>
1257<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1258 <tbody>
1259 <tr>
1260 <td><tt>i1</tt></td>
1261 <td>a single-bit integer.</td>
1262 </tr><tr>
1263 <td><tt>i32</tt></td>
1264 <td>a 32-bit integer.</td>
1265 </tr><tr>
1266 <td><tt>i1942652</tt></td>
1267 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1268 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1269 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1270</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1271</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1272
1273<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1274<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1275
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1276<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1277
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1278<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1279
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1280<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1281sequentially in memory. The array type requires a size (number of
1282elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1283
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1284<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1285
1286<pre>
1287 [&lt;# elements&gt; x &lt;elementtype&gt;]
1288</pre>
1289
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1290<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1291be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1292
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1293<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1294<table class="layout">
1295 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1296 <td class="left"><tt>[40 x i32]</tt></td>
1297 <td class="left">Array of 40 32-bit integer values.</td>
1298 </tr>
1299 <tr class="layout">
1300 <td class="left"><tt>[41 x i32]</tt></td>
1301 <td class="left">Array of 41 32-bit integer values.</td>
1302 </tr>
1303 <tr class="layout">
1304 <td class="left"><tt>[4 x i8]</tt></td>
1305 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1306 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1307</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1308<p>Here are some examples of multidimensional arrays:</p>
1309<table class="layout">
1310 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1311 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1312 <td class="left">3x4 array of 32-bit integer values.</td>
1313 </tr>
1314 <tr class="layout">
1315 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1316 <td class="left">12x10 array of single precision floating point values.</td>
1317 </tr>
1318 <tr class="layout">
1319 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1320 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1321 </tr>
1322</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1323
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1324<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1325length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1326LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1327As a special case, however, zero length arrays are recognized to be variable
1328length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1329type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1330
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1331</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1332
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1333<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1334<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1335<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1336
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1337<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1338
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1339<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1340consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1341return 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]1342If 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]1343class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1344
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1345<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1346
1347<pre>
1348 &lt;returntype list&gt; (&lt;parameter list&gt;)
1349</pre>
1350
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1351<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]1352specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1353which indicates that the function takes a variable number of arguments.
1354Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1355 href="#int_varargs">variable argument handling intrinsic</a> functions.
1356'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1357<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1358
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1359<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1360<table class="layout">
1361 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1362 <td class="left"><tt>i32 (i32)</tt></td>
1363 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1364 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1365 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1366 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1367 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1368 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1369 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1370 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1371 <tt>float</tt>.
1372 </td>
1373 </tr><tr class="layout">
1374 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1375 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1376 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1377 which returns an integer. This is the signature for <tt>printf</tt> in
1378 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1379 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1380 </tr><tr class="layout">
1381 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel8dec6c22008-03-24 18:10:52 +0000[diff] [blame]1382 <td class="left">A function taking an <tt>i32></tt>, returning two
1383 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1384 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1385 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1386</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1387
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1388</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1389<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1390<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1391<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1392<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1393<p>The structure type is used to represent a collection of data members
1394together in memory. The packing of the field types is defined to match
1395the ABI of the underlying processor. The elements of a structure may
1396be any type that has a size.</p>
1397<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1398and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1399field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1400instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1401<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1402<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1403<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1404<table class="layout">
1405 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1406 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1407 <td class="left">A triple of three <tt>i32</tt> values</td>
1408 </tr><tr class="layout">
1409 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1410 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1411 second element is a <a href="#t_pointer">pointer</a> to a
1412 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1413 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1414 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1415</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1416</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1417
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1418<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1419<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1420</div>
1421<div class="doc_text">
1422<h5>Overview:</h5>
1423<p>The packed structure type is used to represent a collection of data members
1424together in memory. There is no padding between fields. Further, the alignment
1425of a packed structure is 1 byte. The elements of a packed structure may
1426be any type that has a size.</p>
1427<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1428and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1429field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1430instruction.</p>
1431<h5>Syntax:</h5>
1432<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1433<h5>Examples:</h5>
1434<table class="layout">
1435 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1436 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1437 <td class="left">A triple of three <tt>i32</tt> values</td>
1438 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1439 <td class="left">
1440<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1441 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1442 second element is a <a href="#t_pointer">pointer</a> to a
1443 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1444 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1445 </tr>
1446</table>
1447</div>
1448
1449<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1450<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1451<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1452<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1453<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1454reference to another object, which must live in memory. Pointer types may have
1455an optional address space attribute defining the target-specific numbered
1456address space where the pointed-to object resides. The default address space is
1457zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1458<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1459<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1460<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1461<table class="layout">
1462 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1463 <td class="left"><tt>[4x i32]*</tt></td>
1464 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1465 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1466 </tr>
1467 <tr class="layout">
1468 <td class="left"><tt>i32 (i32 *) *</tt></td>
1469 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1470 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1471 <tt>i32</tt>.</td>
1472 </tr>
1473 <tr class="layout">
1474 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1475 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1476 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1477 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1478</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1479</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1480
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1481<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1482<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1483<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1484
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1485<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1486
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1487<p>A vector type is a simple derived type that represents a vector
1488of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1489are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1490A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1491elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1492of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1493considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1494
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1495<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1496
1497<pre>
1498 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1499</pre>
1500
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1501<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1502be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1503
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1504<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1505
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1506<table class="layout">
1507 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1508 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1509 <td class="left">Vector of 4 32-bit integer values.</td>
1510 </tr>
1511 <tr class="layout">
1512 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1513 <td class="left">Vector of 8 32-bit floating-point values.</td>
1514 </tr>
1515 <tr class="layout">
1516 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1517 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1518 </tr>
1519</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1520</div>
1521
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1522<!-- _______________________________________________________________________ -->
1523<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1524<div class="doc_text">
1525
1526<h5>Overview:</h5>
1527
1528<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1529corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1530In LLVM, opaque types can eventually be resolved to any type (not just a
1531structure type).</p>
1532
1533<h5>Syntax:</h5>
1534
1535<pre>
1536 opaque
1537</pre>
1538
1539<h5>Examples:</h5>
1540
1541<table class="layout">
1542 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1543 <td class="left"><tt>opaque</tt></td>
1544 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1545 </tr>
1546</table>
1547</div>
1548
1549
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1550<!-- *********************************************************************** -->
1551<div class="doc_section"> <a name="constants">Constants</a> </div>
1552<!-- *********************************************************************** -->
1553
1554<div class="doc_text">
1555
1556<p>LLVM has several different basic types of constants. This section describes
1557them all and their syntax.</p>
1558
1559</div>
1560
1561<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1562<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1563
1564<div class="doc_text">
1565
1566<dl>
1567 <dt><b>Boolean constants</b></dt>
1568
1569 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1570 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1571 </dd>
1572
1573 <dt><b>Integer constants</b></dt>
1574
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1575 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1576 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1577 integer types.
1578 </dd>
1579
1580 <dt><b>Floating point constants</b></dt>
1581
1582 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1583 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1584 notation (see below). The assembler requires the exact decimal value of
1585 a floating-point constant. For example, the assembler accepts 1.25 but
1586 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1587 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1588
1589 <dt><b>Null pointer constants</b></dt>
1590
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1591 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1592 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1593
1594</dl>
1595
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1596<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1597of floating point constants. For example, the form '<tt>double
15980x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
15994.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1600(and the only time that they are generated by the disassembler) is when a
1601floating point constant must be emitted but it cannot be represented as a
1602decimal floating point number. For example, NaN's, infinities, and other
1603special values are represented in their IEEE hexadecimal format so that
1604assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1605
1606</div>
1607
1608<!-- ======================================================================= -->
1609<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1610</div>
1611
1612<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1613<p>Aggregate constants arise from aggregation of simple constants
1614and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1615
1616<dl>
1617 <dt><b>Structure constants</b></dt>
1618
1619 <dd>Structure constants are represented with notation similar to structure
1620 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1621 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1622 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]1623 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1624 types of elements must match those specified by the type.
1625 </dd>
1626
1627 <dt><b>Array constants</b></dt>
1628
1629 <dd>Array constants are represented with notation similar to array type
1630 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1631 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1632 constants must have <a href="#t_array">array type</a>, and the number and
1633 types of elements must match those specified by the type.
1634 </dd>
1635
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1636 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1637
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1638 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1639 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1640 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]1641 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1642 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1643 match those specified by the type.
1644 </dd>
1645
1646 <dt><b>Zero initialization</b></dt>
1647
1648 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1649 value to zero of <em>any</em> type, including scalar and aggregate types.
1650 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]1651 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1652 initializers.
1653 </dd>
1654</dl>
1655
1656</div>
1657
1658<!-- ======================================================================= -->
1659<div class="doc_subsection">
1660 <a name="globalconstants">Global Variable and Function Addresses</a>
1661</div>
1662
1663<div class="doc_text">
1664
1665<p>The addresses of <a href="#globalvars">global variables</a> and <a
1666href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1667constants. These constants are explicitly referenced when the <a
1668href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1669href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1670file:</p>
1671
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1672<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1673<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1674@X = global i32 17
1675@Y = global i32 42
1676@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1677</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1678</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1679
1680</div>
1681
1682<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1683<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1684<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1685 <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]1686 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1687 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1688
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1689 <p>Undefined values indicate to the compiler that the program is well defined
1690 no matter what value is used, giving the compiler more freedom to optimize.
1691 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1692</div>
1693
1694<!-- ======================================================================= -->
1695<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1696</div>
1697
1698<div class="doc_text">
1699
1700<p>Constant expressions are used to allow expressions involving other constants
1701to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1702href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1703that does not have side effects (e.g. load and call are not supported). The
1704following is the syntax for constant expressions:</p>
1705
1706<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1707 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1708 <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]1709 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1710
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1711 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1712 <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]1713 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]1714
1715 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1716 <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]1717 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]1718
1719 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1720 <dd>Truncate a floating point constant to another floating point type. The
1721 size of CST must be larger than the size of TYPE. Both types must be
1722 floating point.</dd>
1723
1724 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1725 <dd>Floating point extend a constant to another type. The size of CST must be
1726 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1727
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1728 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1729 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1730 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1731 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1732 of the same number of elements. If the value won't fit in the integer type,
1733 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1734
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1735 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1736 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1737 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1738 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1739 of the same number of elements. If the value won't fit in the integer type,
1740 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1741
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1742 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1743 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1744 constant. TYPE must be a scalar or vector floating point type. CST must be of
1745 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1746 of the same number of elements. If the value won't fit in the floating point
1747 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1748
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1749 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1750 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1751 constant. TYPE must be a scalar or vector floating point type. CST must be of
1752 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1753 of the same number of elements. If the value won't fit in the floating point
1754 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1755
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1756 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1757 <dd>Convert a pointer typed constant to the corresponding integer constant
1758 TYPE must be an integer type. CST must be of pointer type. The CST value is
1759 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1760
1761 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1762 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1763 pointer type. CST must be of integer type. The CST value is zero extended,
1764 truncated, or unchanged to make it fit in a pointer size. This one is
1765 <i>really</i> dangerous!</dd>
1766
1767 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1768 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1769 identical (same number of bits). The conversion is done as if the CST value
1770 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]1771 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1772 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]1773 pointers it is only valid to cast to another pointer type. It is not valid
1774 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1775 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1776
1777 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1778
1779 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1780 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1781 instruction, the index list may have zero or more indexes, which are required
1782 to make sense for the type of "CSTPTR".</dd>
1783
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1784 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1785
1786 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1787 constants.</dd>
1788
1789 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1790 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1791
1792 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1793 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1794
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1795 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1796 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1797
1798 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1799 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1800
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1801 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1802
1803 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]1804 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1805
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1806 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1807
1808 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1809 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1810
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1811
1812 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1813
1814 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1815 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1816
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1817 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1818
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1819 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1820 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1821 binary</a> operations. The constraints on operands are the same as those for
1822 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1823 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1824</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1825</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1826
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1827<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1828<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1829<!-- *********************************************************************** -->
1830
1831<!-- ======================================================================= -->
1832<div class="doc_subsection">
1833<a name="inlineasm">Inline Assembler Expressions</a>
1834</div>
1835
1836<div class="doc_text">
1837
1838<p>
1839LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1840Module-Level Inline Assembly</a>) through the use of a special value. This
1841value represents the inline assembler as a string (containing the instructions
1842to emit), a list of operand constraints (stored as a string), and a flag that
1843indicates whether or not the inline asm expression has side effects. An example
1844inline assembler expression is:
1845</p>
1846
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1847<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1848<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1849i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1850</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1851</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1852
1853<p>
1854Inline assembler expressions may <b>only</b> be used as the callee operand of
1855a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1856</p>
1857
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1858<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1859<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1860%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]1861</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1862</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1863
1864<p>
1865Inline asms with side effects not visible in the constraint list must be marked
1866as having side effects. This is done through the use of the
1867'<tt>sideeffect</tt>' keyword, like so:
1868</p>
1869
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1870<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1871<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1872call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1873</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1874</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1875
1876<p>TODO: The format of the asm and constraints string still need to be
1877documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]1878need to be documented). This is probably best done by reference to another
1879document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1880</p>
1881
1882</div>
1883
1884<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1885<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1886<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1887
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1888<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1889
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1890<p>The LLVM instruction set consists of several different
1891classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1892instructions</a>, <a href="#binaryops">binary instructions</a>,
1893<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1894 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1895instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1896
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1897</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1898
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1899<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1900<div class="doc_subsection"> <a name="terminators">Terminator
1901Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1903<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1904
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1905<p>As mentioned <a href="#functionstructure">previously</a>, every
1906basic block in a program ends with a "Terminator" instruction, which
1907indicates which block should be executed after the current block is
1908finished. These terminator instructions typically yield a '<tt>void</tt>'
1909value: they produce control flow, not values (the one exception being
1910the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1911<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1912 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1913instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1914the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1915 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1916 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1917
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1918</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1919
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1920<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1921<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1922Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1923<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1924<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1925<pre>
1926 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]1927 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1928</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1929
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1930<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1931
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1932<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1933optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1934<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1935returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1936control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1937
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1938<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1939
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1940<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1941the return value. The type of the return value must be a
1942'<a href="#t_firstclass">first class</a>' type.</p>
1943
1944<p>A function is not <a href="#wellformed">well formed</a> if
1945it it has a non-void return type and contains a '<tt>ret</tt>'
1946instruction with no return value or a return value with a type that
1947does not match its type, or if it has a void return type and contains
1948a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1949
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1950<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1951
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1952<p>When the '<tt>ret</tt>' instruction is executed, control flow
1953returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1954 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1955the instruction after the call. If the caller was an "<a
1956 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1957at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1958returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]1959return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1960
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1961<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1962
1963<pre>
1964 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1965 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1966 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]1967</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1968</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1969<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1970<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1971<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1972<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1973<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]1974</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1975<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1976<p>The '<tt>br</tt>' instruction is used to cause control flow to
1977transfer to a different basic block in the current function. There are
1978two forms of this instruction, corresponding to a conditional branch
1979and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1980<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1981<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1982single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1983unconditional form of the '<tt>br</tt>' instruction takes a single
1984'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1986<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1987argument is evaluated. If the value is <tt>true</tt>, control flows
1988to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1989control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1990<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1991<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]1992 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]1993</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1994<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1995<div class="doc_subsubsection">
1996 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1997</div>
1998
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1999<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2000<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2001
2002<pre>
2003 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2004</pre>
2005
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2006<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2007
2008<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2009several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2010instruction, allowing a branch to occur to one of many possible
2011destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2012
2013
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2014<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2015
2016<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2017comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2018an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2019table is not allowed to contain duplicate constant entries.</p>
2020
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2022
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2023<p>The <tt>switch</tt> instruction specifies a table of values and
2024destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2025table is searched for the given value. If the value is found, control flow is
2026transfered to the corresponding destination; otherwise, control flow is
2027transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2028
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2029<h5>Implementation:</h5>
2030
2031<p>Depending on properties of the target machine and the particular
2032<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2033ways. For example, it could be generated as a series of chained conditional
2034branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2035
2036<h5>Example:</h5>
2037
2038<pre>
2039 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2040 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2041 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2042
2043 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2044 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2045
2046 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2047 switch i32 %val, label %otherwise [ i32 0, label %onzero
2048 i32 1, label %onone
2049 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2050</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2051</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2052
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2053<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2054<div class="doc_subsubsection">
2055 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2056</div>
2057
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2058<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2059
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2060<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2061
2062<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2063 &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]2064 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2065</pre>
2066
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2067<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2068
2069<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2070function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2071'<tt>normal</tt>' label or the
2072'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2073"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2074"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2075href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]2076continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2077
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2078<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2079
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2080<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2082<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2083 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2084 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2085 convention</a> the call should use. If none is specified, the call defaults
2086 to using C calling conventions.
2087 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2088
2089 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2090 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2091 and '<tt>inreg</tt>' attributes are valid here.</li>
2092
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2093 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2094 function value being invoked. In most cases, this is a direct function
2095 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2096 an arbitrary pointer to function value.
2097 </li>
2098
2099 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2100 function to be invoked. </li>
2101
2102 <li>'<tt>function args</tt>': argument list whose types match the function
2103 signature argument types. If the function signature indicates the function
2104 accepts a variable number of arguments, the extra arguments can be
2105 specified. </li>
2106
2107 <li>'<tt>normal label</tt>': the label reached when the called function
2108 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2109
2110 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2111 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2112
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2113 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2114 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2115 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2116</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2117
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2118<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2119
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2120<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2121href="#i_call">call</a></tt>' instruction in most regards. The primary
2122difference is that it establishes an association with a label, which is used by
2123the runtime library to unwind the stack.</p>
2124
2125<p>This instruction is used in languages with destructors to ensure that proper
2126cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2127exception. Additionally, this is important for implementation of
2128'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2129
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2130<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2131<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2132 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2133 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2134 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2135 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2136</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2137</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2138
2139
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2140<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2141
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2142<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2143Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2144
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2145<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2146
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2147<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2148<pre>
2149 unwind
2150</pre>
2151
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2152<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2153
2154<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2155at the first callee in the dynamic call stack which used an <a
2156href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2157primarily used to implement exception handling.</p>
2158
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2159<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2160
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2161<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2162immediately halt. The dynamic call stack is then searched for the first <a
2163href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2164execution continues at the "exceptional" destination block specified by the
2165<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2166dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2167</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2168
2169<!-- _______________________________________________________________________ -->
2170
2171<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2172Instruction</a> </div>
2173
2174<div class="doc_text">
2175
2176<h5>Syntax:</h5>
2177<pre>
2178 unreachable
2179</pre>
2180
2181<h5>Overview:</h5>
2182
2183<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2184instruction is used to inform the optimizer that a particular portion of the
2185code is not reachable. This can be used to indicate that the code after a
2186no-return function cannot be reached, and other facts.</p>
2187
2188<h5>Semantics:</h5>
2189
2190<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2191</div>
2192
2193
2194
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2195<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2196<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2197<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2198<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2199program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2200produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2201multiple 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]2202The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2203<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2204</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2205<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2206<div class="doc_subsubsection">
2207 <a name="i_add">'<tt>add</tt>' Instruction</a>
2208</div>
2209
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2210<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2211
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2212<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2213
2214<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2215 &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]2216</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2217
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2218<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2219
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2220<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2221
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2222<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2223
2224<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2225 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2226 <a href="#t_vector">vector</a> values. Both arguments must have identical
2227 types.</p>
2228
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2229<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2230
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2231<p>The value produced is the integer or floating point sum of the two
2232operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2233
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2234<p>If an integer sum has unsigned overflow, the result returned is the
2235mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2236the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2237
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2238<p>Because LLVM integers use a two's complement representation, this
2239instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2240
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2241<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2242
2243<pre>
2244 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2245</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2246</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2247<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2248<div class="doc_subsubsection">
2249 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2250</div>
2251
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2252<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2253
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2254<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2255
2256<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2257 &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]2258</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2259
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2260<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2261
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2262<p>The '<tt>sub</tt>' instruction returns the difference of its two
2263operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2264
2265<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2266'<tt>neg</tt>' instruction present in most other intermediate
2267representations.</p>
2268
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2269<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2270
2271<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2272 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2273 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2274 types.</p>
2275
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2276<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2277
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2278<p>The value produced is the integer or floating point difference of
2279the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2280
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2281<p>If an integer difference has unsigned overflow, the result returned is the
2282mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2283the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2284
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2285<p>Because LLVM integers use a two's complement representation, this
2286instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2287
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2288<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2289<pre>
2290 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2291 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2292</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2293</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2294
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2295<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2296<div class="doc_subsubsection">
2297 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2298</div>
2299
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2300<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2301
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2302<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2303<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]2304</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2305<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2306<p>The '<tt>mul</tt>' instruction returns the product of its two
2307operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2308
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2309<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2310
2311<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2312href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2313or <a href="#t_vector">vector</a> values. Both arguments must have identical
2314types.</p>
2315
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2316<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2317
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2318<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2319two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2320
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2321<p>If the result of an integer multiplication has unsigned overflow,
2322the result returned is the mathematical result modulo
23232<sup>n</sup>, where n is the bit width of the result.</p>
2324<p>Because LLVM integers use a two's complement representation, and the
2325result is the same width as the operands, this instruction returns the
2326correct result for both signed and unsigned integers. If a full product
2327(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2328should be sign-extended or zero-extended as appropriate to the
2329width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2330<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2331<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]2332</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2333</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2334
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2335<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2336<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2337</a></div>
2338<div class="doc_text">
2339<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2340<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]2341</pre>
2342<h5>Overview:</h5>
2343<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2344operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2345
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2346<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2347
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2348<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2349<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2350values. Both arguments must have identical types.</p>
2351
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2352<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2353
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2354<p>The value produced is the unsigned integer quotient of the two operands.</p>
2355<p>Note that unsigned integer division and signed integer division are distinct
2356operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2357<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2358<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2359<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]2360</pre>
2361</div>
2362<!-- _______________________________________________________________________ -->
2363<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2364</a> </div>
2365<div class="doc_text">
2366<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2367<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2368 &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]2369</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2370
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2371<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2372
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2373<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2374operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2375
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2376<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2377
2378<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2379<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2380values. Both arguments must have identical types.</p>
2381
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2382<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2383<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]2384<p>Note that signed integer division and unsigned integer division are distinct
2385operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2386<p>Division by zero leads to undefined behavior. Overflow also leads to
2387undefined behavior; this is a rare case, but can occur, for example,
2388by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2389<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2390<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]2391</pre>
2392</div>
2393<!-- _______________________________________________________________________ -->
2394<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2395Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2396<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2397<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2398<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2399 &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]2400</pre>
2401<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2402
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2403<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2404operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2405
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2406<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2407
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2408<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2409<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2410of floating point values. Both arguments must have identical types.</p>
2411
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2412<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2413
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2414<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2415
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2416<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2417
2418<pre>
2419 &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]2420</pre>
2421</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2422
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2423<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2424<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2425</div>
2426<div class="doc_text">
2427<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2428<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]2429</pre>
2430<h5>Overview:</h5>
2431<p>The '<tt>urem</tt>' instruction returns the remainder from the
2432unsigned division of its two arguments.</p>
2433<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2434<p>The two arguments to the '<tt>urem</tt>' instruction must be
2435<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2436values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2437<h5>Semantics:</h5>
2438<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2439This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2440<p>Note that unsigned integer remainder and signed integer remainder are
2441distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2442<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2443<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2444<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]2445</pre>
2446
2447</div>
2448<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2449<div class="doc_subsubsection">
2450 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2451</div>
2452
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2453<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2454
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2455<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2456
2457<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2458 &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]2459</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2460
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2461<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2462
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2463<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2464signed division of its two operands. This instruction can also take
2465<a href="#t_vector">vector</a> versions of the values in which case
2466the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2467
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2468<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2469
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2470<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2471<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2472values. Both arguments must have identical types.</p>
2473
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2474<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2475
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2476<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2477has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2478operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2479a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2480 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2481Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2482please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2483Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2484<p>Note that signed integer remainder and unsigned integer remainder are
2485distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2486<p>Taking the remainder of a division by zero leads to undefined behavior.
2487Overflow also leads to undefined behavior; this is a rare case, but can occur,
2488for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2489(The remainder doesn't actually overflow, but this rule lets srem be
2490implemented using instructions that return both the result of the division
2491and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2492<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2493<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]2494</pre>
2495
2496</div>
2497<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2498<div class="doc_subsubsection">
2499 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2500
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2501<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2502
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2503<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2504<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]2505</pre>
2506<h5>Overview:</h5>
2507<p>The '<tt>frem</tt>' instruction returns the remainder from the
2508division of its two operands.</p>
2509<h5>Arguments:</h5>
2510<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2511<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2512of floating point values. Both arguments must have identical types.</p>
2513
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2514<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2515
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2516<p>This instruction returns the <i>remainder</i> of a division.
2517The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2518
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2519<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2520
2521<pre>
2522 &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]2523</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2524</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2525
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2526<!-- ======================================================================= -->
2527<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2528Operations</a> </div>
2529<div class="doc_text">
2530<p>Bitwise binary operators are used to do various forms of
2531bit-twiddling in a program. They are generally very efficient
2532instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2533instructions. They require two operands of the same type, execute an operation on them,
2534and 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]2535</div>
2536
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2537<!-- _______________________________________________________________________ -->
2538<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2539Instruction</a> </div>
2540<div class="doc_text">
2541<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2542<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]2543</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2544
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2545<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2546
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2547<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2548the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2549
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2550<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2551
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2552<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2553 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2554type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2555
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2556<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2557
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2558<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2559where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2560equal 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]2561
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2562<h5>Example:</h5><pre>
2563 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2564 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2565 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2566 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2567</pre>
2568</div>
2569<!-- _______________________________________________________________________ -->
2570<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2571Instruction</a> </div>
2572<div class="doc_text">
2573<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2574<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]2575</pre>
2576
2577<h5>Overview:</h5>
2578<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2579operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2580
2581<h5>Arguments:</h5>
2582<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2583<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]2584type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2585
2586<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2587
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2588<p>This instruction always performs a logical shift right operation. The most
2589significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2590shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2591the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2592
2593<h5>Example:</h5>
2594<pre>
2595 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2596 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2597 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2598 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2599 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2600</pre>
2601</div>
2602
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2603<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2604<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2605Instruction</a> </div>
2606<div class="doc_text">
2607
2608<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2609<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]2610</pre>
2611
2612<h5>Overview:</h5>
2613<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2614operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2615
2616<h5>Arguments:</h5>
2617<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2618<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]2619type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2620
2621<h5>Semantics:</h5>
2622<p>This instruction always performs an arithmetic shift right operation,
2623The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2624of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2625larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2626</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2627
2628<h5>Example:</h5>
2629<pre>
2630 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2631 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2632 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2633 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2634 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2635</pre>
2636</div>
2637
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2638<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2639<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2640Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2641
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2642<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2643
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2644<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2645
2646<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2647 &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]2648</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2649
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2650<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2651
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2652<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2653its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2654
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2655<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2656
2657<p>The two arguments to the '<tt>and</tt>' instruction must be
2658<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2659values. Both arguments must have identical types.</p>
2660
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2661<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2662<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2663<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2664<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2665<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2666 <tbody>
2667 <tr>
2668 <td>In0</td>
2669 <td>In1</td>
2670 <td>Out</td>
2671 </tr>
2672 <tr>
2673 <td>0</td>
2674 <td>0</td>
2675 <td>0</td>
2676 </tr>
2677 <tr>
2678 <td>0</td>
2679 <td>1</td>
2680 <td>0</td>
2681 </tr>
2682 <tr>
2683 <td>1</td>
2684 <td>0</td>
2685 <td>0</td>
2686 </tr>
2687 <tr>
2688 <td>1</td>
2689 <td>1</td>
2690 <td>1</td>
2691 </tr>
2692 </tbody>
2693</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2694</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2695<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2696<pre>
2697 &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]2698 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2699 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2700</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2701</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2702<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2703<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2704<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2705<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2706<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]2707</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2708<h5>Overview:</h5>
2709<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2710or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2711<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2712
2713<p>The two arguments to the '<tt>or</tt>' instruction must be
2714<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2715values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2716<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2717<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2718<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2719<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2720<table border="1" cellspacing="0" cellpadding="4">
2721 <tbody>
2722 <tr>
2723 <td>In0</td>
2724 <td>In1</td>
2725 <td>Out</td>
2726 </tr>
2727 <tr>
2728 <td>0</td>
2729 <td>0</td>
2730 <td>0</td>
2731 </tr>
2732 <tr>
2733 <td>0</td>
2734 <td>1</td>
2735 <td>1</td>
2736 </tr>
2737 <tr>
2738 <td>1</td>
2739 <td>0</td>
2740 <td>1</td>
2741 </tr>
2742 <tr>
2743 <td>1</td>
2744 <td>1</td>
2745 <td>1</td>
2746 </tr>
2747 </tbody>
2748</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2749</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2750<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2751<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2752 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2753 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2754</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2755</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2756<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2757<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2758Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2759<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2760<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2761<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]2762</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2763<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2764<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2765or of its two operands. The <tt>xor</tt> is used to implement the
2766"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2767<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2768<p>The two arguments to the '<tt>xor</tt>' instruction must be
2769<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2770values. Both arguments must have identical types.</p>
2771
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2772<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2773
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2774<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2775<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2776<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2777<table border="1" cellspacing="0" cellpadding="4">
2778 <tbody>
2779 <tr>
2780 <td>In0</td>
2781 <td>In1</td>
2782 <td>Out</td>
2783 </tr>
2784 <tr>
2785 <td>0</td>
2786 <td>0</td>
2787 <td>0</td>
2788 </tr>
2789 <tr>
2790 <td>0</td>
2791 <td>1</td>
2792 <td>1</td>
2793 </tr>
2794 <tr>
2795 <td>1</td>
2796 <td>0</td>
2797 <td>1</td>
2798 </tr>
2799 <tr>
2800 <td>1</td>
2801 <td>1</td>
2802 <td>0</td>
2803 </tr>
2804 </tbody>
2805</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2806</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2807<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2808<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2809<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2810 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2811 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2812 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2813</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2814</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2815
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2816<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2817<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2818 <a name="vectorops">Vector Operations</a>
2819</div>
2820
2821<div class="doc_text">
2822
2823<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2824target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2825vector-specific operations needed to process vectors effectively. While LLVM
2826does directly support these vector operations, many sophisticated algorithms
2827will want to use target-specific intrinsics to take full advantage of a specific
2828target.</p>
2829
2830</div>
2831
2832<!-- _______________________________________________________________________ -->
2833<div class="doc_subsubsection">
2834 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2835</div>
2836
2837<div class="doc_text">
2838
2839<h5>Syntax:</h5>
2840
2841<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2842 &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]2843</pre>
2844
2845<h5>Overview:</h5>
2846
2847<p>
2848The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2849element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2850</p>
2851
2852
2853<h5>Arguments:</h5>
2854
2855<p>
2856The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2857value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2858an index indicating the position from which to extract the element.
2859The index may be a variable.</p>
2860
2861<h5>Semantics:</h5>
2862
2863<p>
2864The result is a scalar of the same type as the element type of
2865<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2866<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2867results are undefined.
2868</p>
2869
2870<h5>Example:</h5>
2871
2872<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2873 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2874</pre>
2875</div>
2876
2877
2878<!-- _______________________________________________________________________ -->
2879<div class="doc_subsubsection">
2880 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2881</div>
2882
2883<div class="doc_text">
2884
2885<h5>Syntax:</h5>
2886
2887<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2888 &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]2889</pre>
2890
2891<h5>Overview:</h5>
2892
2893<p>
2894The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2895element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2896</p>
2897
2898
2899<h5>Arguments:</h5>
2900
2901<p>
2902The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2903value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2904scalar value whose type must equal the element type of the first
2905operand. The third operand is an index indicating the position at
2906which to insert the value. The index may be a variable.</p>
2907
2908<h5>Semantics:</h5>
2909
2910<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2911The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2912element values are those of <tt>val</tt> except at position
2913<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2914exceeds the length of <tt>val</tt>, the results are undefined.
2915</p>
2916
2917<h5>Example:</h5>
2918
2919<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2920 %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]2921</pre>
2922</div>
2923
2924<!-- _______________________________________________________________________ -->
2925<div class="doc_subsubsection">
2926 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2927</div>
2928
2929<div class="doc_text">
2930
2931<h5>Syntax:</h5>
2932
2933<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2934 &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;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2935</pre>
2936
2937<h5>Overview:</h5>
2938
2939<p>
2940The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2941from two input vectors, returning a vector of the same type.
2942</p>
2943
2944<h5>Arguments:</h5>
2945
2946<p>
2947The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2948with types that match each other and types that match the result of the
2949instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2950of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2951</p>
2952
2953<p>
2954The shuffle mask operand is required to be a constant vector with either
2955constant integer or undef values.
2956</p>
2957
2958<h5>Semantics:</h5>
2959
2960<p>
2961The elements of the two input vectors are numbered from left to right across
2962both of the vectors. The shuffle mask operand specifies, for each element of
2963the result vector, which element of the two input registers the result element
2964gets. The element selector may be undef (meaning "don't care") and the second
2965operand may be undef if performing a shuffle from only one vector.
2966</p>
2967
2968<h5>Example:</h5>
2969
2970<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2971 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2972 &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]2973 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2974 &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.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2975</pre>
2976</div>
2977
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2978
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2979<!-- ======================================================================= -->
2980<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2981 <a name="aggregateops">Aggregate Operations</a>
2982</div>
2983
2984<div class="doc_text">
2985
2986<p>LLVM supports several instructions for working with aggregate values.
2987</p>
2988
2989</div>
2990
2991<!-- _______________________________________________________________________ -->
2992<div class="doc_subsubsection">
2993 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
2994</div>
2995
2996<div class="doc_text">
2997
2998<h5>Syntax:</h5>
2999
3000<pre>
3001 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3002</pre>
3003
3004<h5>Overview:</h5>
3005
3006<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3007The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3008or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3009</p>
3010
3011
3012<h5>Arguments:</h5>
3013
3014<p>
3015The first operand of an '<tt>extractvalue</tt>' instruction is a
3016value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3017type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3018in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3019'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3020</p>
3021
3022<h5>Semantics:</h5>
3023
3024<p>
3025The result is the value at the position in the aggregate specified by
3026the index operands.
3027</p>
3028
3029<h5>Example:</h5>
3030
3031<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3032 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3033</pre>
3034</div>
3035
3036
3037<!-- _______________________________________________________________________ -->
3038<div class="doc_subsubsection">
3039 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3040</div>
3041
3042<div class="doc_text">
3043
3044<h5>Syntax:</h5>
3045
3046<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3047 &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]3048</pre>
3049
3050<h5>Overview:</h5>
3051
3052<p>
3053The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3054into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3055</p>
3056
3057
3058<h5>Arguments:</h5>
3059
3060<p>
3061The first operand of an '<tt>insertvalue</tt>' instruction is a
3062value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3063The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3064The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3065indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3066indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3067'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3068The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3069by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3070</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3071
3072<h5>Semantics:</h5>
3073
3074<p>
3075The result is an aggregate of the same type as <tt>val</tt>. Its
3076value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3077specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3078</p>
3079
3080<h5>Example:</h5>
3081
3082<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3083 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3084</pre>
3085</div>
3086
3087
3088<!-- ======================================================================= -->
3089<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3090 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3091</div>
3092
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3093<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3094
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3095<p>A key design point of an SSA-based representation is how it
3096represents memory. In LLVM, no memory locations are in SSA form, which
3097makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3098allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3099
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3100</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3101
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3102<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3103<div class="doc_subsubsection">
3104 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3105</div>
3106
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3107<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3108
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3109<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3110
3111<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3112 &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]3113</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3114
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3115<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3116
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3117<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3118heap and returns a pointer to it. The object is always allocated in the generic
3119address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3120
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3121<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3122
3123<p>The '<tt>malloc</tt>' instruction allocates
3124<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3125bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3126appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3127number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3128If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3129be aligned to at least that boundary. If not specified, or if zero, the target can
3130choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3131
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3132<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3133
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3134<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3135
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3136<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3137a pointer is returned. The result of a zero byte allocattion is undefined. The
3138result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3139
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3140<h5>Example:</h5>
3141
3142<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3143 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3144
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3145 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3146 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3147 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3148 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3149 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3150</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3151</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3152
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3153<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3154<div class="doc_subsubsection">
3155 <a name="i_free">'<tt>free</tt>' Instruction</a>
3156</div>
3157
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3158<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3159
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3160<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3161
3162<pre>
3163 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3164</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3165
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3166<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3167
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3168<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3169memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3170
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3171<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3172
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3173<p>'<tt>value</tt>' shall be a pointer value that points to a value
3174that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3175instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3176
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3177<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3178
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3179<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3180after this instruction executes. If the pointer is null, the operation
3181is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3182
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3183<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3184
3185<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3186 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3187 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3188</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3189</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3190
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3191<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3192<div class="doc_subsubsection">
3193 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3194</div>
3195
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3196<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3199
3200<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3201 &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]3202</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3203
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3205
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3206<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3207currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3208returns to its caller. The object is always allocated in the generic address
3209space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3210
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3211<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3212
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3213<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3214bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3215appropriate type to the program. If "NumElements" is specified, it is the
3216number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3217If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3218to be aligned to at least that boundary. If not specified, or if zero, the target
3219can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3220
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3221<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3222
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3223<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3224
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3225<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3226there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3227memory is automatically released when the function returns. The '<tt>alloca</tt>'
3228instruction is commonly used to represent automatic variables that must
3229have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3230 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]3231instructions), the memory is reclaimed. Allocating zero bytes
3232is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3233
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3234<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3235
3236<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3237 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3238 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3239 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3240 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3241</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3242</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3243
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3244<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3245<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3246Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3247<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3248<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3249<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]3250<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3251<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3252<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3253<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3254address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3255 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3256marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3257the number or order of execution of this <tt>load</tt> with other
3258volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3259instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3260<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3261The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3262(that is, the alignment of the memory address). A value of 0 or an
3263omitted "align" argument means that the operation has the preferential
3264alignment for the target. It is the responsibility of the code emitter
3265to ensure that the alignment information is correct. Overestimating
3266the alignment results in an undefined behavior. Underestimating the
3267alignment may produce less efficient code. An alignment of 1 is always
3268safe.
3269</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3270<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3271<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3272<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3273<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3274 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3275 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3276 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3277</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3278</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3279<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3280<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3281Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3282<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3283<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3284<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3285 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]3286</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3287<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3288<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3289<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3290<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3291to 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]3292operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3293of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3294operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3295optimizer is not allowed to modify the number or order of execution of
3296this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3297 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3298<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3299The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3300(that is, the alignment of the memory address). A value of 0 or an
3301omitted "align" argument means that the operation has the preferential
3302alignment for the target. It is the responsibility of the code emitter
3303to ensure that the alignment information is correct. Overestimating
3304the alignment results in an undefined behavior. Underestimating the
3305alignment may produce less efficient code. An alignment of 1 is always
3306safe.
3307</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3308<h5>Semantics:</h5>
3309<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3310at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3311<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3312<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3313 store i32 3, i32* %ptr <i>; yields {void}</i>
3314 %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]3315</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3316</div>
3317
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3318<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3319<div class="doc_subsubsection">
3320 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3321</div>
3322
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3323<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3324<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3325<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3326 &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]3327</pre>
3328
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3329<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3330
3331<p>
3332The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3333subelement of an aggregate data structure. It performs address calculation only
3334and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3335
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3336<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3337
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3338<p>The first argument is always a pointer, and forms the basis of the
3339calculation. The remaining arguments are indices, that indicate which of the
3340elements of the aggregate object are indexed. The interpretation of each index
3341is dependent on the type being indexed into. The first index always indexes the
3342pointer value given as the first argument, the second index indexes a value of
3343the type pointed to (not necessarily the value directly pointed to, since the
3344first index can be non-zero), etc. The first type indexed into must be a pointer
3345value, subsequent types can be arrays, vectors and structs. Note that subsequent
3346types being indexed into can never be pointers, since that would require loading
3347the pointer before continuing calculation.</p>
3348
3349<p>The type of each index argument depends on the type it is indexing into.
3350When indexing into a (packed) structure, only <tt>i32</tt> integer
3351<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3352only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3353will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3354
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3355<p>For example, let's consider a C code fragment and how it gets
3356compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3357
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3358<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3359<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3360struct RT {
3361 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3362 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3363 char C;
3364};
3365struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3366 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3367 double Y;
3368 struct RT Z;
3369};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3370
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3371int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3372 return &amp;s[1].Z.B[5][13];
3373}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3374</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3375</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3376
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3377<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3378
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3379<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3380<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3381%RT = type { i8 , [10 x [20 x i32]], i8 }
3382%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3383
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3384define i32* %foo(%ST* %s) {
3385entry:
3386 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3387 ret i32* %reg
3388}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3389</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3390</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3391
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3392<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3393
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3394<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]3395type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3396}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3397the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3398i8 }</tt>' type, another structure. The third index indexes into the second
3399element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3400array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3401'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3402to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3403
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3404<p>Note that it is perfectly legal to index partially through a
3405structure, returning a pointer to an inner element. Because of this,
3406the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3407
3408<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3409 define i32* %foo(%ST* %s) {
3410 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3411 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3412 %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]3413 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3414 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3415 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3416 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3417</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3418
3419<p>Note that it is undefined to access an array out of bounds: array and
3420pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3421The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3422defined to be accessible as variable length arrays, which requires access
3423beyond the zero'th element.</p>
3424
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3425<p>The getelementptr instruction is often confusing. For some more insight
3426into how it works, see <a href="GetElementPtr.html">the getelementptr
3427FAQ</a>.</p>
3428
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3429<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3430
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3431<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3432 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3433 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3434 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3435 %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]3436 <i>; yields i8*:eptr</i>
3437 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3438</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3439</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3440
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3441<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3442<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3443</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3444<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3445<p>The instructions in this category are the conversion instructions (casting)
3446which all take a single operand and a type. They perform various bit conversions
3447on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3448</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3449
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3450<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3451<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3452 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3453</div>
3454<div class="doc_text">
3455
3456<h5>Syntax:</h5>
3457<pre>
3458 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3459</pre>
3460
3461<h5>Overview:</h5>
3462<p>
3463The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3464</p>
3465
3466<h5>Arguments:</h5>
3467<p>
3468The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3469be 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]3470and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3471type. The bit size of <tt>value</tt> must be larger than the bit size of
3472<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3473
3474<h5>Semantics:</h5>
3475<p>
3476The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3477and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3478larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3479It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3480
3481<h5>Example:</h5>
3482<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3483 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3484 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3485 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3486</pre>
3487</div>
3488
3489<!-- _______________________________________________________________________ -->
3490<div class="doc_subsubsection">
3491 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3492</div>
3493<div class="doc_text">
3494
3495<h5>Syntax:</h5>
3496<pre>
3497 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3498</pre>
3499
3500<h5>Overview:</h5>
3501<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3502<tt>ty2</tt>.</p>
3503
3504
3505<h5>Arguments:</h5>
3506<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]3507<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3508also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3509<tt>value</tt> must be smaller than the bit size of the destination type,
3510<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3511
3512<h5>Semantics:</h5>
3513<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]3514bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3515
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3516<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]3517
3518<h5>Example:</h5>
3519<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3520 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3521 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3522</pre>
3523</div>
3524
3525<!-- _______________________________________________________________________ -->
3526<div class="doc_subsubsection">
3527 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3528</div>
3529<div class="doc_text">
3530
3531<h5>Syntax:</h5>
3532<pre>
3533 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3534</pre>
3535
3536<h5>Overview:</h5>
3537<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3538
3539<h5>Arguments:</h5>
3540<p>
3541The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3542<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3543also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3544<tt>value</tt> must be smaller than the bit size of the destination type,
3545<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3546
3547<h5>Semantics:</h5>
3548<p>
3549The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3550bit (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]3551the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3552
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3553<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]3554
3555<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3556<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3557 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3558 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3559</pre>
3560</div>
3561
3562<!-- _______________________________________________________________________ -->
3563<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3564 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3565</div>
3566
3567<div class="doc_text">
3568
3569<h5>Syntax:</h5>
3570
3571<pre>
3572 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3573</pre>
3574
3575<h5>Overview:</h5>
3576<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3577<tt>ty2</tt>.</p>
3578
3579
3580<h5>Arguments:</h5>
3581<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3582 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3583cast it to. The size of <tt>value</tt> must be larger than the size of
3584<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3585<i>no-op cast</i>.</p>
3586
3587<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3588<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3589<a href="#t_floating">floating point</a> type to a smaller
3590<a href="#t_floating">floating point</a> type. If the value cannot fit within
3591the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3592
3593<h5>Example:</h5>
3594<pre>
3595 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3596 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3597</pre>
3598</div>
3599
3600<!-- _______________________________________________________________________ -->
3601<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3602 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3603</div>
3604<div class="doc_text">
3605
3606<h5>Syntax:</h5>
3607<pre>
3608 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3609</pre>
3610
3611<h5>Overview:</h5>
3612<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3613floating point value.</p>
3614
3615<h5>Arguments:</h5>
3616<p>The '<tt>fpext</tt>' instruction takes a
3617<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3618and a <a href="#t_floating">floating point</a> type to cast it to. The source
3619type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3620
3621<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3622<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3623<a href="#t_floating">floating point</a> type to a larger
3624<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3625used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3626<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]3627
3628<h5>Example:</h5>
3629<pre>
3630 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3631 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3632</pre>
3633</div>
3634
3635<!-- _______________________________________________________________________ -->
3636<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3637 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3638</div>
3639<div class="doc_text">
3640
3641<h5>Syntax:</h5>
3642<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3643 &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]3644</pre>
3645
3646<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3647<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3648unsigned integer equivalent of type <tt>ty2</tt>.
3649</p>
3650
3651<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3652<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]3653scalar or vector <a href="#t_floating">floating point</a> value, and a type
3654to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3655type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3656vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3657
3658<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3659<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3660<a href="#t_floating">floating point</a> operand into the nearest (rounding
3661towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3662the results are undefined.</p>
3663
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3664<h5>Example:</h5>
3665<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3666 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3667 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3668 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3669</pre>
3670</div>
3671
3672<!-- _______________________________________________________________________ -->
3673<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3674 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3675</div>
3676<div class="doc_text">
3677
3678<h5>Syntax:</h5>
3679<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3680 &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]3681</pre>
3682
3683<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3684<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3685<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]3686</p>
3687
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3688<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3689<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]3690scalar or vector <a href="#t_floating">floating point</a> value, and a type
3691to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3692type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3693vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3694
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3695<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3696<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3697<a href="#t_floating">floating point</a> operand into the nearest (rounding
3698towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3699the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3700
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3701<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3702<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3703 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3704 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3705 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3706</pre>
3707</div>
3708
3709<!-- _______________________________________________________________________ -->
3710<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3711 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3712</div>
3713<div class="doc_text">
3714
3715<h5>Syntax:</h5>
3716<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3717 &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]3718</pre>
3719
3720<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3721<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3722integer and converts that value to the <tt>ty2</tt> type.</p>
3723
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3724<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3725<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3726scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3727to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3728type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3729floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3730
3731<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3732<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3733integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3734the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3735
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3736<h5>Example:</h5>
3737<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3738 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3739 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3740</pre>
3741</div>
3742
3743<!-- _______________________________________________________________________ -->
3744<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3745 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3746</div>
3747<div class="doc_text">
3748
3749<h5>Syntax:</h5>
3750<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3751 &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]3752</pre>
3753
3754<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3755<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3756integer and converts that value to the <tt>ty2</tt> type.</p>
3757
3758<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3759<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3760scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3761to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3762type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3763floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3764
3765<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3766<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3767integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3768the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3769
3770<h5>Example:</h5>
3771<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3772 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3773 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3774</pre>
3775</div>
3776
3777<!-- _______________________________________________________________________ -->
3778<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3779 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3780</div>
3781<div class="doc_text">
3782
3783<h5>Syntax:</h5>
3784<pre>
3785 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3786</pre>
3787
3788<h5>Overview:</h5>
3789<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3790the integer type <tt>ty2</tt>.</p>
3791
3792<h5>Arguments:</h5>
3793<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3794must 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^]3795<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]3796
3797<h5>Semantics:</h5>
3798<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3799<tt>ty2</tt> by interpreting the pointer value as an integer and either
3800truncating or zero extending that value to the size of the integer type. If
3801<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3802<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]3803are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3804change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3805
3806<h5>Example:</h5>
3807<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3808 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3809 %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]3810</pre>
3811</div>
3812
3813<!-- _______________________________________________________________________ -->
3814<div class="doc_subsubsection">
3815 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3816</div>
3817<div class="doc_text">
3818
3819<h5>Syntax:</h5>
3820<pre>
3821 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3822</pre>
3823
3824<h5>Overview:</h5>
3825<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3826a pointer type, <tt>ty2</tt>.</p>
3827
3828<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3829<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3830value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3831<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3832
3833<h5>Semantics:</h5>
3834<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3835<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3836the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3837size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3838the size of a pointer then a zero extension is done. If they are the same size,
3839nothing is done (<i>no-op cast</i>).</p>
3840
3841<h5>Example:</h5>
3842<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3843 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3844 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3845 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3846</pre>
3847</div>
3848
3849<!-- _______________________________________________________________________ -->
3850<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3851 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3852</div>
3853<div class="doc_text">
3854
3855<h5>Syntax:</h5>
3856<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3857 &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]3858</pre>
3859
3860<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3861
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3862<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3863<tt>ty2</tt> without changing any bits.</p>
3864
3865<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3866
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3867<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]3868a non-aggregate first class value, and a type to cast it to, which must also be
3869a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3870<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3871and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3872type is a pointer, the destination type must also be a pointer. This
3873instruction supports bitwise conversion of vectors to integers and to vectors
3874of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3875
3876<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3877<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3878<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3879this conversion. The conversion is done as if the <tt>value</tt> had been
3880stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3881converted to other pointer types with this instruction. To convert pointers to
3882other types, use the <a href="#i_inttoptr">inttoptr</a> or
3883<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3884
3885<h5>Example:</h5>
3886<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3887 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3888 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3889 %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]3890</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3891</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3892
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3893<!-- ======================================================================= -->
3894<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3895<div class="doc_text">
3896<p>The instructions in this category are the "miscellaneous"
3897instructions, which defy better classification.</p>
3898</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3899
3900<!-- _______________________________________________________________________ -->
3901<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3902</div>
3903<div class="doc_text">
3904<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3905<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]3906</pre>
3907<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3908<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3909a vector of boolean values based on comparison
3910of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3911<h5>Arguments:</h5>
3912<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3913the condition code indicating the kind of comparison to perform. It is not
3914a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3915</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3916<ol>
3917 <li><tt>eq</tt>: equal</li>
3918 <li><tt>ne</tt>: not equal </li>
3919 <li><tt>ugt</tt>: unsigned greater than</li>
3920 <li><tt>uge</tt>: unsigned greater or equal</li>
3921 <li><tt>ult</tt>: unsigned less than</li>
3922 <li><tt>ule</tt>: unsigned less or equal</li>
3923 <li><tt>sgt</tt>: signed greater than</li>
3924 <li><tt>sge</tt>: signed greater or equal</li>
3925 <li><tt>slt</tt>: signed less than</li>
3926 <li><tt>sle</tt>: signed less or equal</li>
3927</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3928<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3929<a href="#t_pointer">pointer</a>
3930or integer <a href="#t_vector">vector</a> typed.
3931They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3932<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3933<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]3934the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3935yields 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^]3936</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3937<ol>
3938 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3939 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3940 </li>
3941 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3942 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3943 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3944 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3945 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3946 <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]3947 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3948 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3949 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3950 <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]3951 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3952 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3953 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3954 <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]3955 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3956 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3957 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3958 <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]3959</ol>
3960<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3961values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3962<p>If the operands are integer vectors, then they are compared
3963element by element. The result is an <tt>i1</tt> vector with
3964the same number of elements as the values being compared.
3965Otherwise, the result is an <tt>i1</tt>.
3966</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3967
3968<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3969<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3970 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3971 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3972 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3973 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3974 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3975</pre>
3976</div>
3977
3978<!-- _______________________________________________________________________ -->
3979<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3980</div>
3981<div class="doc_text">
3982<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3983<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]3984</pre>
3985<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3986<p>The '<tt>fcmp</tt>' instruction returns a boolean value
3987or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3988of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3989<p>
3990If the operands are floating point scalars, then the result
3991type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
3992</p>
3993<p>If the operands are floating point vectors, then the result type
3994is a vector of boolean with the same number of elements as the
3995operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3996<h5>Arguments:</h5>
3997<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3998the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]3999a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4000<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4001 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4002 <li><tt>oeq</tt>: ordered and equal</li>
4003 <li><tt>ogt</tt>: ordered and greater than </li>
4004 <li><tt>oge</tt>: ordered and greater than or equal</li>
4005 <li><tt>olt</tt>: ordered and less than </li>
4006 <li><tt>ole</tt>: ordered and less than or equal</li>
4007 <li><tt>one</tt>: ordered and not equal</li>
4008 <li><tt>ord</tt>: ordered (no nans)</li>
4009 <li><tt>ueq</tt>: unordered or equal</li>
4010 <li><tt>ugt</tt>: unordered or greater than </li>
4011 <li><tt>uge</tt>: unordered or greater than or equal</li>
4012 <li><tt>ult</tt>: unordered or less than </li>
4013 <li><tt>ule</tt>: unordered or less than or equal</li>
4014 <li><tt>une</tt>: unordered or not equal</li>
4015 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4016 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4017</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4018<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4019<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4020<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4021either a <a href="#t_floating">floating point</a> type
4022or a <a href="#t_vector">vector</a> of floating point type.
4023They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4024<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4025<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4026according to the condition code given as <tt>cond</tt>.
4027If the operands are vectors, then the vectors are compared
4028element by element.
4029Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4030always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4031<ol>
4032 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4033 <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]4034 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4035 <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]4036 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4037 <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]4038 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4039 <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]4040 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4041 <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]4042 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4043 <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]4044 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4045 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4046 <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]4047 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4048 <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]4049 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4050 <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]4051 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4052 <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]4053 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4054 <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]4055 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4056 <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]4057 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4058 <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]4059 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4060</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4061
4062<h5>Example:</h5>
4063<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]4064 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4065 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4066 &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]4067</pre>
4068</div>
4069
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4070<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4071<div class="doc_subsubsection">
4072 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4073</div>
4074<div class="doc_text">
4075<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4076<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]4077</pre>
4078<h5>Overview:</h5>
4079<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4080element-wise comparison of its two integer vector operands.</p>
4081<h5>Arguments:</h5>
4082<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4083the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4084a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4085<ol>
4086 <li><tt>eq</tt>: equal</li>
4087 <li><tt>ne</tt>: not equal </li>
4088 <li><tt>ugt</tt>: unsigned greater than</li>
4089 <li><tt>uge</tt>: unsigned greater or equal</li>
4090 <li><tt>ult</tt>: unsigned less than</li>
4091 <li><tt>ule</tt>: unsigned less or equal</li>
4092 <li><tt>sgt</tt>: signed greater than</li>
4093 <li><tt>sge</tt>: signed greater or equal</li>
4094 <li><tt>slt</tt>: signed less than</li>
4095 <li><tt>sle</tt>: signed less or equal</li>
4096</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4097<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4098<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4099<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4100<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4101according to the condition code given as <tt>cond</tt>. The comparison yields a
4102<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4103identical type as the values being compared. The most significant bit in each
4104element is 1 if the element-wise comparison evaluates to true, and is 0
4105otherwise. All other bits of the result are undefined. The condition codes
4106are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4107instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4108
4109<h5>Example:</h5>
4110<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4111 &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>
4112 &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]4113</pre>
4114</div>
4115
4116<!-- _______________________________________________________________________ -->
4117<div class="doc_subsubsection">
4118 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4119</div>
4120<div class="doc_text">
4121<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4122<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]4123<h5>Overview:</h5>
4124<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4125element-wise comparison of its two floating point vector operands. The output
4126elements have the same width as the input elements.</p>
4127<h5>Arguments:</h5>
4128<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4129the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4130a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4131<ol>
4132 <li><tt>false</tt>: no comparison, always returns false</li>
4133 <li><tt>oeq</tt>: ordered and equal</li>
4134 <li><tt>ogt</tt>: ordered and greater than </li>
4135 <li><tt>oge</tt>: ordered and greater than or equal</li>
4136 <li><tt>olt</tt>: ordered and less than </li>
4137 <li><tt>ole</tt>: ordered and less than or equal</li>
4138 <li><tt>one</tt>: ordered and not equal</li>
4139 <li><tt>ord</tt>: ordered (no nans)</li>
4140 <li><tt>ueq</tt>: unordered or equal</li>
4141 <li><tt>ugt</tt>: unordered or greater than </li>
4142 <li><tt>uge</tt>: unordered or greater than or equal</li>
4143 <li><tt>ult</tt>: unordered or less than </li>
4144 <li><tt>ule</tt>: unordered or less than or equal</li>
4145 <li><tt>une</tt>: unordered or not equal</li>
4146 <li><tt>uno</tt>: unordered (either nans)</li>
4147 <li><tt>true</tt>: no comparison, always returns true</li>
4148</ol>
4149<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4150<a href="#t_floating">floating point</a> typed. They must also be identical
4151types.</p>
4152<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4153<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4154according to the condition code given as <tt>cond</tt>. The comparison yields a
4155<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4156an identical number of elements as the values being compared, and each element
4157having identical with to the width of the floating point elements. The most
4158significant bit in each element is 1 if the element-wise comparison evaluates to
4159true, and is 0 otherwise. All other bits of the result are undefined. The
4160condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4161<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4162
4163<h5>Example:</h5>
4164<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4165 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4166 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4167
4168 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4169 &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]4170</pre>
4171</div>
4172
4173<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4174<div class="doc_subsubsection">
4175 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4176</div>
4177
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4178<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4179
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4180<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4181
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4182<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4183<h5>Overview:</h5>
4184<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4185the SSA graph representing the function.</p>
4186<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4187
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4188<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4189field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4190as arguments, with one pair for each predecessor basic block of the
4191current block. Only values of <a href="#t_firstclass">first class</a>
4192type may be used as the value arguments to the PHI node. Only labels
4193may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4194
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4195<p>There must be no non-phi instructions between the start of a basic
4196block and the PHI instructions: i.e. PHI instructions must be first in
4197a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4198
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4199<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4200
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4201<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4202specified by the pair corresponding to the predecessor basic block that executed
4203just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4204
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4205<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4206<pre>
4207Loop: ; Infinite loop that counts from 0 on up...
4208 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4209 %nextindvar = add i32 %indvar, 1
4210 br label %Loop
4211</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4212</div>
4213
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4214<!-- _______________________________________________________________________ -->
4215<div class="doc_subsubsection">
4216 <a name="i_select">'<tt>select</tt>' Instruction</a>
4217</div>
4218
4219<div class="doc_text">
4220
4221<h5>Syntax:</h5>
4222
4223<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4224 &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>
4225
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4226 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4227</pre>
4228
4229<h5>Overview:</h5>
4230
4231<p>
4232The '<tt>select</tt>' instruction is used to choose one value based on a
4233condition, without branching.
4234</p>
4235
4236
4237<h5>Arguments:</h5>
4238
4239<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4240The '<tt>select</tt>' instruction requires an 'i1' value or
4241a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4242condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4243type. If the val1/val2 are vectors and
4244the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4245individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4246</p>
4247
4248<h5>Semantics:</h5>
4249
4250<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4251If 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]4252value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4253</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4254<p>
4255If the condition is a vector of i1, then the value arguments must
4256be vectors of the same size, and the selection is done element
4257by element.
4258</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4259
4260<h5>Example:</h5>
4261
4262<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4263 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4264</pre>
4265</div>
4266
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4267
4268<!-- _______________________________________________________________________ -->
4269<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4270 <a name="i_call">'<tt>call</tt>' Instruction</a>
4271</div>
4272
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4273<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4274
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4275<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4276<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4277 &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]4278</pre>
4279
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4280<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4281
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4282<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4283
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4284<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4285
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4286<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4287
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4288<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4289 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4290 <p>The optional "tail" marker indicates whether the callee function accesses
4291 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4292 function call is eligible for tail call optimization. Note that calls may
4293 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4294 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4295 </li>
4296 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4297 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4298 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4299 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4300 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4301
4302 <li>
4303 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4304 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4305 and '<tt>inreg</tt>' attributes are valid here.</p>
4306 </li>
4307
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4308 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4309 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4310 the type of the return value. Functions that return no value are marked
4311 <tt><a href="#t_void">void</a></tt>.</p>
4312 </li>
4313 <li>
4314 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4315 value being invoked. The argument types must match the types implied by
4316 this signature. This type can be omitted if the function is not varargs
4317 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4318 </li>
4319 <li>
4320 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4321 be invoked. In most cases, this is a direct function invocation, but
4322 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4323 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4324 </li>
4325 <li>
4326 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4327 function signature argument types. All arguments must be of
4328 <a href="#t_firstclass">first class</a> type. If the function signature
4329 indicates the function accepts a variable number of arguments, the extra
4330 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4331 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4332 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4333 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4334 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4335 '<tt>readnone</tt>' attributes are valid here.</p>
4336 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4337</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4338
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4339<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4340
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4341<p>The '<tt>call</tt>' instruction is used to cause control flow to
4342transfer to a specified function, with its incoming arguments bound to
4343the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4344instruction in the called function, control flow continues with the
4345instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4346function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4347
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4348<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4349
4350<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4351 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4352 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4353 %X = tail call i32 @foo() <i>; yields i32</i>
4354 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4355 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4356
4357 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4358 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4359 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4360 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4361 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4362 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4363</pre>
4364
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4365</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4366
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4367<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4368<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4369 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4370</div>
4371
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4372<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4373
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4374<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4375
4376<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4377 &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]4378</pre>
4379
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4380<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4381
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4382<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4383the "variable argument" area of a function call. It is used to implement the
4384<tt>va_arg</tt> macro in C.</p>
4385
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4386<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4387
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4388<p>This instruction takes a <tt>va_list*</tt> value and the type of
4389the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4390increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4391actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4392
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4393<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4394
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4395<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4396type from the specified <tt>va_list</tt> and causes the
4397<tt>va_list</tt> to point to the next argument. For more information,
4398see the variable argument handling <a href="#int_varargs">Intrinsic
4399Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4400
4401<p>It is legal for this instruction to be called in a function which does not
4402take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4403function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4404
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4405<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4406href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4407argument.</p>
4408
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4409<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4410
4411<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4412
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4413</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4414
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4415<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4416<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4417<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4418
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4419<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4420
4421<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4422well known names and semantics and are required to follow certain restrictions.
4423Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4424language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4425adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4426
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4427<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4428prefix is reserved in LLVM for intrinsic names; thus, function names may not
4429begin with this prefix. Intrinsic functions must always be external functions:
4430you cannot define the body of intrinsic functions. Intrinsic functions may
4431only be used in call or invoke instructions: it is illegal to take the address
4432of an intrinsic function. Additionally, because intrinsic functions are part
4433of the LLVM language, it is required if any are added that they be documented
4434here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4435
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4436<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4437a family of functions that perform the same operation but on different data
4438types. Because LLVM can represent over 8 million different integer types,
4439overloading is used commonly to allow an intrinsic function to operate on any
4440integer type. One or more of the argument types or the result type can be
4441overloaded to accept any integer type. Argument types may also be defined as
4442exactly matching a previous argument's type or the result type. This allows an
4443intrinsic function which accepts multiple arguments, but needs all of them to
4444be of the same type, to only be overloaded with respect to a single argument or
4445the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4446
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4447<p>Overloaded intrinsics will have the names of its overloaded argument types
4448encoded into its function name, each preceded by a period. Only those types
4449which are overloaded result in a name suffix. Arguments whose type is matched
4450against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4451take an integer of any width and returns an integer of exactly the same integer
4452width. This leads to a family of functions such as
4453<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4454Only one type, the return type, is overloaded, and only one type suffix is
4455required. Because the argument's type is matched against the return type, it
4456does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4457
4458<p>To learn how to add an intrinsic function, please see the
4459<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4460</p>
4461
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4462</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4463
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4464<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4465<div class="doc_subsection">
4466 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4467</div>
4468
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4469<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4470
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4471<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4472 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4473intrinsic functions. These functions are related to the similarly
4474named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4475
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4476<p>All of these functions operate on arguments that use a
4477target-specific value type "<tt>va_list</tt>". The LLVM assembly
4478language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4479transformations should be prepared to handle these functions regardless of
4480the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4481
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4482<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]4483instruction and the variable argument handling intrinsic functions are
4484used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4485
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4486<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4487<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4488define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4489 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4490 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4491 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4492 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4493
4494 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4495 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4496
4497 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4498 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4499 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4500 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4501 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4502
4503 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4504 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4505 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4506}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4507
4508declare void @llvm.va_start(i8*)
4509declare void @llvm.va_copy(i8*, i8*)
4510declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4511</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4512</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4513
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4514</div>
4515
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4516<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4517<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4518 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4519</div>
4520
4521
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4522<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4523<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4524<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4525<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4526<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4527<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4528href="#i_va_arg">va_arg</a></tt>.</p>
4529
4530<h5>Arguments:</h5>
4531
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4532<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]4533
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4534<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4535
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]4536<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]4537macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4538<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]4539<tt>va_arg</tt> will produce the first variable argument passed to the function.
4540Unlike 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]4541last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4542
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4543</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4544
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4545<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4546<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4547 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4548</div>
4549
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4550<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4551<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4552<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4553<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4554
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4555<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4556which 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]4557or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4558
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4559<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4560
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4561<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]4562
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4563<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4564
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4565<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]4566macro available in C. In a target-dependent way, it destroys the
4567<tt>va_list</tt> element to which the argument points. Calls to <a
4568href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4569<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4570<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4571
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4572</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4573
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4574<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4575<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4576 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4577</div>
4578
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4579<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4580
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4581<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4582
4583<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4584 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4585</pre>
4586
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4587<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4588
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4589<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4590from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4591
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4592<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4593
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4594<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]4595The 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]4596
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4597
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4598<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4599
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4600<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4601macro available in C. In a target-dependent way, it copies the source
4602<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4603intrinsic is necessary because the <tt><a href="#int_va_start">
4604llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4605example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4606
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4607</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4608
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4609<!-- ======================================================================= -->
4610<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4611 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4612</div>
4613
4614<div class="doc_text">
4615
4616<p>
4617LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4618Collection</a> (GC) requires the implementation and generation of these
4619intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4620These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4621stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4622href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4623Front-ends for type-safe garbage collected languages should generate these
4624intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4625href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4626</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4627
4628<p>The garbage collection intrinsics only operate on objects in the generic
4629 address space (address space zero).</p>
4630
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4631</div>
4632
4633<!-- _______________________________________________________________________ -->
4634<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4635 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4636</div>
4637
4638<div class="doc_text">
4639
4640<h5>Syntax:</h5>
4641
4642<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4643 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4644</pre>
4645
4646<h5>Overview:</h5>
4647
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4648<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]4649the code generator, and allows some metadata to be associated with it.</p>
4650
4651<h5>Arguments:</h5>
4652
4653<p>The first argument specifies the address of a stack object that contains the
4654root pointer. The second pointer (which must be either a constant or a global
4655value address) contains the meta-data to be associated with the root.</p>
4656
4657<h5>Semantics:</h5>
4658
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4659<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]4660location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4661the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4662intrinsic may only be used in a function which <a href="#gc">specifies a GC
4663algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4664
4665</div>
4666
4667
4668<!-- _______________________________________________________________________ -->
4669<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4670 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4671</div>
4672
4673<div class="doc_text">
4674
4675<h5>Syntax:</h5>
4676
4677<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4678 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4679</pre>
4680
4681<h5>Overview:</h5>
4682
4683<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4684locations, allowing garbage collector implementations that require read
4685barriers.</p>
4686
4687<h5>Arguments:</h5>
4688
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4689<p>The second argument is the address to read from, which should be an address
4690allocated from the garbage collector. The first object is a pointer to the
4691start of the referenced object, if needed by the language runtime (otherwise
4692null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4693
4694<h5>Semantics:</h5>
4695
4696<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4697instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4698garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4699may only be used in a function which <a href="#gc">specifies a GC
4700algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4701
4702</div>
4703
4704
4705<!-- _______________________________________________________________________ -->
4706<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4707 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4708</div>
4709
4710<div class="doc_text">
4711
4712<h5>Syntax:</h5>
4713
4714<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4715 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4716</pre>
4717
4718<h5>Overview:</h5>
4719
4720<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4721locations, allowing garbage collector implementations that require write
4722barriers (such as generational or reference counting collectors).</p>
4723
4724<h5>Arguments:</h5>
4725
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4726<p>The first argument is the reference to store, the second is the start of the
4727object to store it to, and the third is the address of the field of Obj to
4728store to. If the runtime does not require a pointer to the object, Obj may be
4729null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4730
4731<h5>Semantics:</h5>
4732
4733<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4734instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4735garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4736may only be used in a function which <a href="#gc">specifies a GC
4737algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4738
4739</div>
4740
4741
4742
4743<!-- ======================================================================= -->
4744<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4745 <a name="int_codegen">Code Generator Intrinsics</a>
4746</div>
4747
4748<div class="doc_text">
4749<p>
4750These intrinsics are provided by LLVM to expose special features that may only
4751be implemented with code generator support.
4752</p>
4753
4754</div>
4755
4756<!-- _______________________________________________________________________ -->
4757<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4758 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4759</div>
4760
4761<div class="doc_text">
4762
4763<h5>Syntax:</h5>
4764<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4765 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4766</pre>
4767
4768<h5>Overview:</h5>
4769
4770<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4771The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4772target-specific value indicating the return address of the current function
4773or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4774</p>
4775
4776<h5>Arguments:</h5>
4777
4778<p>
4779The argument to this intrinsic indicates which function to return the address
4780for. Zero indicates the calling function, one indicates its caller, etc. The
4781argument is <b>required</b> to be a constant integer value.
4782</p>
4783
4784<h5>Semantics:</h5>
4785
4786<p>
4787The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4788the return address of the specified call frame, or zero if it cannot be
4789identified. The value returned by this intrinsic is likely to be incorrect or 0
4790for arguments other than zero, so it should only be used for debugging purposes.
4791</p>
4792
4793<p>
4794Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4795aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4796source-language caller.
4797</p>
4798</div>
4799
4800
4801<!-- _______________________________________________________________________ -->
4802<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4803 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4804</div>
4805
4806<div class="doc_text">
4807
4808<h5>Syntax:</h5>
4809<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4810 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4811</pre>
4812
4813<h5>Overview:</h5>
4814
4815<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4816The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4817target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4818</p>
4819
4820<h5>Arguments:</h5>
4821
4822<p>
4823The argument to this intrinsic indicates which function to return the frame
4824pointer for. Zero indicates the calling function, one indicates its caller,
4825etc. The argument is <b>required</b> to be a constant integer value.
4826</p>
4827
4828<h5>Semantics:</h5>
4829
4830<p>
4831The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4832the frame address of the specified call frame, or zero if it cannot be
4833identified. The value returned by this intrinsic is likely to be incorrect or 0
4834for arguments other than zero, so it should only be used for debugging purposes.
4835</p>
4836
4837<p>
4838Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4839aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4840source-language caller.
4841</p>
4842</div>
4843
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4844<!-- _______________________________________________________________________ -->
4845<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4846 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4847</div>
4848
4849<div class="doc_text">
4850
4851<h5>Syntax:</h5>
4852<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4853 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4854</pre>
4855
4856<h5>Overview:</h5>
4857
4858<p>
4859The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4860the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4861<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4862features like scoped automatic variable sized arrays in C99.
4863</p>
4864
4865<h5>Semantics:</h5>
4866
4867<p>
4868This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4869href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4870<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4871<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4872state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4873practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4874that were allocated after the <tt>llvm.stacksave</tt> was executed.
4875</p>
4876
4877</div>
4878
4879<!-- _______________________________________________________________________ -->
4880<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4881 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4882</div>
4883
4884<div class="doc_text">
4885
4886<h5>Syntax:</h5>
4887<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4888 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4889</pre>
4890
4891<h5>Overview:</h5>
4892
4893<p>
4894The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4895the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4896href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4897useful for implementing language features like scoped automatic variable sized
4898arrays in C99.
4899</p>
4900
4901<h5>Semantics:</h5>
4902
4903<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4904See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4905</p>
4906
4907</div>
4908
4909
4910<!-- _______________________________________________________________________ -->
4911<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4912 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4913</div>
4914
4915<div class="doc_text">
4916
4917<h5>Syntax:</h5>
4918<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4919 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]4920</pre>
4921
4922<h5>Overview:</h5>
4923
4924
4925<p>
4926The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4927a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4928no
4929effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4930characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4931</p>
4932
4933<h5>Arguments:</h5>
4934
4935<p>
4936<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4937determining if the fetch should be for a read (0) or write (1), and
4938<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4939locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4940<tt>locality</tt> arguments must be constant integers.
4941</p>
4942
4943<h5>Semantics:</h5>
4944
4945<p>
4946This intrinsic does not modify the behavior of the program. In particular,
4947prefetches cannot trap and do not produce a value. On targets that support this
4948intrinsic, the prefetch can provide hints to the processor cache for better
4949performance.
4950</p>
4951
4952</div>
4953
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4954<!-- _______________________________________________________________________ -->
4955<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4956 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4957</div>
4958
4959<div class="doc_text">
4960
4961<h5>Syntax:</h5>
4962<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4963 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4964</pre>
4965
4966<h5>Overview:</h5>
4967
4968
4969<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4970The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4971(PC) in a region of
4972code to simulators and other tools. The method is target specific, but it is
4973expected that the marker will use exported symbols to transmit the PC of the
4974marker.
4975The marker makes no guarantees that it will remain with any specific instruction
4976after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4977optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4978correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4979</p>
4980
4981<h5>Arguments:</h5>
4982
4983<p>
4984<tt>id</tt> is a numerical id identifying the marker.
4985</p>
4986
4987<h5>Semantics:</h5>
4988
4989<p>
4990This intrinsic does not modify the behavior of the program. Backends that do not
4991support this intrinisic may ignore it.
4992</p>
4993
4994</div>
4995
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4996<!-- _______________________________________________________________________ -->
4997<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4998 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4999</div>
5000
5001<div class="doc_text">
5002
5003<h5>Syntax:</h5>
5004<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5005 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5006</pre>
5007
5008<h5>Overview:</h5>
5009
5010
5011<p>
5012The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5013counter register (or similar low latency, high accuracy clocks) on those targets
5014that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5015As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5016should only be used for small timings.
5017</p>
5018
5019<h5>Semantics:</h5>
5020
5021<p>
5022When directly supported, reading the cycle counter should not modify any memory.
5023Implementations are allowed to either return a application specific value or a
5024system wide value. On backends without support, this is lowered to a constant 0.
5025</p>
5026
5027</div>
5028
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5029<!-- ======================================================================= -->
5030<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5031 <a name="int_libc">Standard C Library Intrinsics</a>
5032</div>
5033
5034<div class="doc_text">
5035<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5036LLVM provides intrinsics for a few important standard C library functions.
5037These intrinsics allow source-language front-ends to pass information about the
5038alignment of the pointer arguments to the code generator, providing opportunity
5039for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5040</p>
5041
5042</div>
5043
5044<!-- _______________________________________________________________________ -->
5045<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5046 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5047</div>
5048
5049<div class="doc_text">
5050
5051<h5>Syntax:</h5>
5052<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5053 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5054 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5055 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5056 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5057</pre>
5058
5059<h5>Overview:</h5>
5060
5061<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5062The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5063location to the destination location.
5064</p>
5065
5066<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5067Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5068intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5069</p>
5070
5071<h5>Arguments:</h5>
5072
5073<p>
5074The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5075the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5076specifying the number of bytes to copy, and the fourth argument is the alignment
5077of the source and destination locations.
5078</p>
5079
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5080<p>
5081If 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]5082the caller guarantees that both the source and destination pointers are aligned
5083to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5084</p>
5085
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5086<h5>Semantics:</h5>
5087
5088<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5089The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5090location to the destination location, which are not allowed to overlap. It
5091copies "len" bytes of memory over. If the argument is known to be aligned to
5092some boundary, this can be specified as the fourth argument, otherwise it should
5093be set to 0 or 1.
5094</p>
5095</div>
5096
5097
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5098<!-- _______________________________________________________________________ -->
5099<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5100 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5101</div>
5102
5103<div class="doc_text">
5104
5105<h5>Syntax:</h5>
5106<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5107 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5108 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5109 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5110 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5111</pre>
5112
5113<h5>Overview:</h5>
5114
5115<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5116The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5117location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5118'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5119</p>
5120
5121<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5122Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5123intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5124</p>
5125
5126<h5>Arguments:</h5>
5127
5128<p>
5129The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5130the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5131specifying the number of bytes to copy, and the fourth argument is the alignment
5132of the source and destination locations.
5133</p>
5134
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5135<p>
5136If 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]5137the caller guarantees that the source and destination pointers are aligned to
5138that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5139</p>
5140
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5141<h5>Semantics:</h5>
5142
5143<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5144The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5145location to the destination location, which may overlap. It
5146copies "len" bytes of memory over. If the argument is known to be aligned to
5147some boundary, this can be specified as the fourth argument, otherwise it should
5148be set to 0 or 1.
5149</p>
5150</div>
5151
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5152
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5153<!-- _______________________________________________________________________ -->
5154<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5155 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5156</div>
5157
5158<div class="doc_text">
5159
5160<h5>Syntax:</h5>
5161<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5162 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5163 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5164 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5165 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5166</pre>
5167
5168<h5>Overview:</h5>
5169
5170<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5171The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5172byte value.
5173</p>
5174
5175<p>
5176Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5177does not return a value, and takes an extra alignment argument.
5178</p>
5179
5180<h5>Arguments:</h5>
5181
5182<p>
5183The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5184byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5185argument specifying the number of bytes to fill, and the fourth argument is the
5186known alignment of destination location.
5187</p>
5188
5189<p>
5190If 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]5191the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5192</p>
5193
5194<h5>Semantics:</h5>
5195
5196<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5197The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5198the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5199destination location. If the argument is known to be aligned to some boundary,
5200this can be specified as the fourth argument, otherwise it should be set to 0 or
52011.
5202</p>
5203</div>
5204
5205
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5206<!-- _______________________________________________________________________ -->
5207<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5208 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5209</div>
5210
5211<div class="doc_text">
5212
5213<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5214<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]5215floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5216types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5217<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5218 declare float @llvm.sqrt.f32(float %Val)
5219 declare double @llvm.sqrt.f64(double %Val)
5220 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5221 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5222 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5223</pre>
5224
5225<h5>Overview:</h5>
5226
5227<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5228The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5229returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5230<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5231negative numbers other than -0.0 (which allows for better optimization, because
5232there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5233defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5234</p>
5235
5236<h5>Arguments:</h5>
5237
5238<p>
5239The argument and return value are floating point numbers of the same type.
5240</p>
5241
5242<h5>Semantics:</h5>
5243
5244<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5245This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5246floating point number.
5247</p>
5248</div>
5249
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5250<!-- _______________________________________________________________________ -->
5251<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5252 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5253</div>
5254
5255<div class="doc_text">
5256
5257<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5258<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]5259floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5260types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5261<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5262 declare float @llvm.powi.f32(float %Val, i32 %power)
5263 declare double @llvm.powi.f64(double %Val, i32 %power)
5264 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5265 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5266 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5267</pre>
5268
5269<h5>Overview:</h5>
5270
5271<p>
5272The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5273specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5274multiplications is not defined. When a vector of floating point type is
5275used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5276</p>
5277
5278<h5>Arguments:</h5>
5279
5280<p>
5281The second argument is an integer power, and the first is a value to raise to
5282that power.
5283</p>
5284
5285<h5>Semantics:</h5>
5286
5287<p>
5288This function returns the first value raised to the second power with an
5289unspecified sequence of rounding operations.</p>
5290</div>
5291
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5292<!-- _______________________________________________________________________ -->
5293<div class="doc_subsubsection">
5294 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5295</div>
5296
5297<div class="doc_text">
5298
5299<h5>Syntax:</h5>
5300<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5301floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5302types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5303<pre>
5304 declare float @llvm.sin.f32(float %Val)
5305 declare double @llvm.sin.f64(double %Val)
5306 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5307 declare fp128 @llvm.sin.f128(fp128 %Val)
5308 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5309</pre>
5310
5311<h5>Overview:</h5>
5312
5313<p>
5314The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5315</p>
5316
5317<h5>Arguments:</h5>
5318
5319<p>
5320The argument and return value are floating point numbers of the same type.
5321</p>
5322
5323<h5>Semantics:</h5>
5324
5325<p>
5326This function returns the sine of the specified operand, returning the
5327same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5328conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5329</div>
5330
5331<!-- _______________________________________________________________________ -->
5332<div class="doc_subsubsection">
5333 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5334</div>
5335
5336<div class="doc_text">
5337
5338<h5>Syntax:</h5>
5339<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5340floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5341types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5342<pre>
5343 declare float @llvm.cos.f32(float %Val)
5344 declare double @llvm.cos.f64(double %Val)
5345 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5346 declare fp128 @llvm.cos.f128(fp128 %Val)
5347 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5348</pre>
5349
5350<h5>Overview:</h5>
5351
5352<p>
5353The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5354</p>
5355
5356<h5>Arguments:</h5>
5357
5358<p>
5359The argument and return value are floating point numbers of the same type.
5360</p>
5361
5362<h5>Semantics:</h5>
5363
5364<p>
5365This function returns the cosine of the specified operand, returning the
5366same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5367conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5368</div>
5369
5370<!-- _______________________________________________________________________ -->
5371<div class="doc_subsubsection">
5372 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5373</div>
5374
5375<div class="doc_text">
5376
5377<h5>Syntax:</h5>
5378<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5379floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5380types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5381<pre>
5382 declare float @llvm.pow.f32(float %Val, float %Power)
5383 declare double @llvm.pow.f64(double %Val, double %Power)
5384 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5385 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5386 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5387</pre>
5388
5389<h5>Overview:</h5>
5390
5391<p>
5392The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5393specified (positive or negative) power.
5394</p>
5395
5396<h5>Arguments:</h5>
5397
5398<p>
5399The second argument is a floating point power, and the first is a value to
5400raise to that power.
5401</p>
5402
5403<h5>Semantics:</h5>
5404
5405<p>
5406This function returns the first value raised to the second power,
5407returning the
5408same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5409conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5410</div>
5411
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5412
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5413<!-- ======================================================================= -->
5414<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5415 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5416</div>
5417
5418<div class="doc_text">
5419<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5420LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5421These allow efficient code generation for some algorithms.
5422</p>
5423
5424</div>
5425
5426<!-- _______________________________________________________________________ -->
5427<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5428 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5429</div>
5430
5431<div class="doc_text">
5432
5433<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5434<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5435type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5436<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5437 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5438 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5439 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5440</pre>
5441
5442<h5>Overview:</h5>
5443
5444<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5445The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5446values with an even number of bytes (positive multiple of 16 bits). These are
5447useful for performing operations on data that is not in the target's native
5448byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5449</p>
5450
5451<h5>Semantics:</h5>
5452
5453<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5454The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5455and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5456intrinsic returns an i32 value that has the four bytes of the input i32
5457swapped, 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]5458i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5459<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5460additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5461</p>
5462
5463</div>
5464
5465<!-- _______________________________________________________________________ -->
5466<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5467 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5468</div>
5469
5470<div class="doc_text">
5471
5472<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5473<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^]5474width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5475<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5476 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5477 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5478 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5479 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5480 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5481</pre>
5482
5483<h5>Overview:</h5>
5484
5485<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5486The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5487value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5488</p>
5489
5490<h5>Arguments:</h5>
5491
5492<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5493The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5494integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5495</p>
5496
5497<h5>Semantics:</h5>
5498
5499<p>
5500The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5501</p>
5502</div>
5503
5504<!-- _______________________________________________________________________ -->
5505<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5506 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5507</div>
5508
5509<div class="doc_text">
5510
5511<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5512<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^]5513integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5514<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5515 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5516 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5517 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5518 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5519 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5520</pre>
5521
5522<h5>Overview:</h5>
5523
5524<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5525The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5526leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5527</p>
5528
5529<h5>Arguments:</h5>
5530
5531<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5532The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5533integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5534</p>
5535
5536<h5>Semantics:</h5>
5537
5538<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5539The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5540in 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]5541of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5542</p>
5543</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5544
5545
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5546
5547<!-- _______________________________________________________________________ -->
5548<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5549 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5550</div>
5551
5552<div class="doc_text">
5553
5554<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5555<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^]5556integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5557<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5558 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5559 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5560 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5561 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5562 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5563</pre>
5564
5565<h5>Overview:</h5>
5566
5567<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5568The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5569trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5570</p>
5571
5572<h5>Arguments:</h5>
5573
5574<p>
5575The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5576integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5577</p>
5578
5579<h5>Semantics:</h5>
5580
5581<p>
5582The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5583in a variable. If the src == 0 then the result is the size in bits of the type
5584of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5585</p>
5586</div>
5587
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5588<!-- _______________________________________________________________________ -->
5589<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5590 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5591</div>
5592
5593<div class="doc_text">
5594
5595<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5596<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5597on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5598<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5599 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5600 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5601</pre>
5602
5603<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5604<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5605range of bits from an integer value and returns them in the same bit width as
5606the original value.</p>
5607
5608<h5>Arguments:</h5>
5609<p>The first argument, <tt>%val</tt> and the result may be integer types of
5610any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5611arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5612
5613<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5614<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5615of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5616<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5617operates in forward mode.</p>
5618<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5619right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5620only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5621<ol>
5622 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5623 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5624 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5625 to determine the number of bits to retain.</li>
5626 <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^]5627 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5628</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5629<p>In reverse mode, a similar computation is made except that the bits are
5630returned in the reverse order. So, for example, if <tt>X</tt> has the value
5631<tt>i16 0x0ACF (101011001111)</tt> and we apply
5632<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5633<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5634</div>
5635
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5636<div class="doc_subsubsection">
5637 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5638</div>
5639
5640<div class="doc_text">
5641
5642<h5>Syntax:</h5>
5643<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5644on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5645<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5646 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5647 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]5648</pre>
5649
5650<h5>Overview:</h5>
5651<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5652of bits in an integer value with another integer value. It returns the integer
5653with the replaced bits.</p>
5654
5655<h5>Arguments:</h5>
5656<p>The first argument, <tt>%val</tt> and the result may be integer types of
5657any bit width but they must have the same bit width. <tt>%val</tt> is the value
5658whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5659integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5660type since they specify only a bit index.</p>
5661
5662<h5>Semantics:</h5>
5663<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5664of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5665<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5666operates in forward mode.</p>
5667<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5668truncating it down to the size of the replacement area or zero extending it
5669up to that size.</p>
5670<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5671are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5672in <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^]5673to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5674<p>In reverse mode, a similar computation is made except that the bits are
5675reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5676<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]5677<h5>Examples:</h5>
5678<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5679 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5680 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5681 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5682 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5683 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5684</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5685</div>
5686
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5687<!-- ======================================================================= -->
5688<div class="doc_subsection">
5689 <a name="int_debugger">Debugger Intrinsics</a>
5690</div>
5691
5692<div class="doc_text">
5693<p>
5694The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5695are described in the <a
5696href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5697Debugging</a> document.
5698</p>
5699</div>
5700
5701
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5702<!-- ======================================================================= -->
5703<div class="doc_subsection">
5704 <a name="int_eh">Exception Handling Intrinsics</a>
5705</div>
5706
5707<div class="doc_text">
5708<p> The LLVM exception handling intrinsics (which all start with
5709<tt>llvm.eh.</tt> prefix), are described in the <a
5710href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5711Handling</a> document. </p>
5712</div>
5713
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5714<!-- ======================================================================= -->
5715<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5716 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5717</div>
5718
5719<div class="doc_text">
5720<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5721 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5722 the <tt>nest</tt> attribute, from a function. The result is a callable
5723 function pointer lacking the nest parameter - the caller does not need
5724 to provide a value for it. Instead, the value to use is stored in
5725 advance in a "trampoline", a block of memory usually allocated
5726 on the stack, which also contains code to splice the nest value into the
5727 argument list. This is used to implement the GCC nested function address
5728 extension.
5729</p>
5730<p>
5731 For example, if the function is
5732 <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]5733 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]5734<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5735 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5736 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5737 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5738 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5739</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5740 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5741 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5742</div>
5743
5744<!-- _______________________________________________________________________ -->
5745<div class="doc_subsubsection">
5746 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5747</div>
5748<div class="doc_text">
5749<h5>Syntax:</h5>
5750<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5751declare 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]5752</pre>
5753<h5>Overview:</h5>
5754<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5755 This fills the memory pointed to by <tt>tramp</tt> with code
5756 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5757</p>
5758<h5>Arguments:</h5>
5759<p>
5760 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5761 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5762 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5763 intrinsic. Note that the size and the alignment are target-specific - LLVM
5764 currently provides no portable way of determining them, so a front-end that
5765 generates this intrinsic needs to have some target-specific knowledge.
5766 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]5767</p>
5768<h5>Semantics:</h5>
5769<p>
5770 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5771 dependent code, turning it into a function. A pointer to this function is
5772 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5773 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5774 before being called. The new function's signature is the same as that of
5775 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5776 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5777 of pointer type. Calling the new function is equivalent to calling
5778 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5779 missing <tt>nest</tt> argument. If, after calling
5780 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5781 modified, then the effect of any later call to the returned function pointer is
5782 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5783</p>
5784</div>
5785
5786<!-- ======================================================================= -->
5787<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5788 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5789</div>
5790
5791<div class="doc_text">
5792<p>
5793 These intrinsic functions expand the "universal IR" of LLVM to represent
5794 hardware constructs for atomic operations and memory synchronization. This
5795 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5796 is aimed at a low enough level to allow any programming models or APIs
5797 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5798 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5799 hardware behavior. Just as hardware provides a "universal IR" for source
5800 languages, it also provides a starting point for developing a "universal"
5801 atomic operation and synchronization IR.
5802</p>
5803<p>
5804 These do <em>not</em> form an API such as high-level threading libraries,
5805 software transaction memory systems, atomic primitives, and intrinsic
5806 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5807 application libraries. The hardware interface provided by LLVM should allow
5808 a clean implementation of all of these APIs and parallel programming models.
5809 No one model or paradigm should be selected above others unless the hardware
5810 itself ubiquitously does so.
5811
5812</p>
5813</div>
5814
5815<!-- _______________________________________________________________________ -->
5816<div class="doc_subsubsection">
5817 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5818</div>
5819<div class="doc_text">
5820<h5>Syntax:</h5>
5821<pre>
5822declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5823i1 &lt;device&gt; )
5824
5825</pre>
5826<h5>Overview:</h5>
5827<p>
5828 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5829 specific pairs of memory access types.
5830</p>
5831<h5>Arguments:</h5>
5832<p>
5833 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5834 The first four arguments enables a specific barrier as listed below. The fith
5835 argument specifies that the barrier applies to io or device or uncached memory.
5836
5837</p>
5838 <ul>
5839 <li><tt>ll</tt>: load-load barrier</li>
5840 <li><tt>ls</tt>: load-store barrier</li>
5841 <li><tt>sl</tt>: store-load barrier</li>
5842 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]5843 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5844 </ul>
5845<h5>Semantics:</h5>
5846<p>
5847 This intrinsic causes the system to enforce some ordering constraints upon
5848 the loads and stores of the program. This barrier does not indicate
5849 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5850 which they occur. For any of the specified pairs of load and store operations
5851 (f.ex. load-load, or store-load), all of the first operations preceding the
5852 barrier will complete before any of the second operations succeeding the
5853 barrier begin. Specifically the semantics for each pairing is as follows:
5854</p>
5855 <ul>
5856 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5857 after the barrier begins.</li>
5858
5859 <li><tt>ls</tt>: All loads before the barrier must complete before any
5860 store after the barrier begins.</li>
5861 <li><tt>ss</tt>: All stores before the barrier must complete before any
5862 store after the barrier begins.</li>
5863 <li><tt>sl</tt>: All stores before the barrier must complete before any
5864 load after the barrier begins.</li>
5865 </ul>
5866<p>
5867 These semantics are applied with a logical "and" behavior when more than one
5868 is enabled in a single memory barrier intrinsic.
5869</p>
5870<p>
5871 Backends may implement stronger barriers than those requested when they do not
5872 support as fine grained a barrier as requested. Some architectures do not
5873 need all types of barriers and on such architectures, these become noops.
5874</p>
5875<h5>Example:</h5>
5876<pre>
5877%ptr = malloc i32
5878 store i32 4, %ptr
5879
5880%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5881 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5882 <i>; guarantee the above finishes</i>
5883 store i32 8, %ptr <i>; before this begins</i>
5884</pre>
5885</div>
5886
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5887<!-- _______________________________________________________________________ -->
5888<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5889 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5890</div>
5891<div class="doc_text">
5892<h5>Syntax:</h5>
5893<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5894 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5895 any integer bit width and for different address spaces. Not all targets
5896 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5897
5898<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5899declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5900declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5901declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5902declare 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]5903
5904</pre>
5905<h5>Overview:</h5>
5906<p>
5907 This loads a value in memory and compares it to a given value. If they are
5908 equal, it stores a new value into the memory.
5909</p>
5910<h5>Arguments:</h5>
5911<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5912 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5913 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5914 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5915 this integer type. While any bit width integer may be used, targets may only
5916 lower representations they support in hardware.
5917
5918</p>
5919<h5>Semantics:</h5>
5920<p>
5921 This entire intrinsic must be executed atomically. It first loads the value
5922 in memory pointed to by <tt>ptr</tt> and compares it with the value
5923 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5924 loaded value is yielded in all cases. This provides the equivalent of an
5925 atomic compare-and-swap operation within the SSA framework.
5926</p>
5927<h5>Examples:</h5>
5928
5929<pre>
5930%ptr = malloc i32
5931 store i32 4, %ptr
5932
5933%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5934%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5935 <i>; yields {i32}:result1 = 4</i>
5936%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5937%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5938
5939%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5940%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5941 <i>; yields {i32}:result2 = 8</i>
5942%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5943
5944%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5945</pre>
5946</div>
5947
5948<!-- _______________________________________________________________________ -->
5949<div class="doc_subsubsection">
5950 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5951</div>
5952<div class="doc_text">
5953<h5>Syntax:</h5>
5954
5955<p>
5956 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5957 integer bit width. Not all targets support all bit widths however.</p>
5958<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5959declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5960declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5961declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5962declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5963
5964</pre>
5965<h5>Overview:</h5>
5966<p>
5967 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5968 the value from memory. It then stores the value in <tt>val</tt> in the memory
5969 at <tt>ptr</tt>.
5970</p>
5971<h5>Arguments:</h5>
5972
5973<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5974 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5975 <tt>val</tt> argument and the result must be integers of the same bit width.
5976 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5977 integer type. The targets may only lower integer representations they
5978 support.
5979</p>
5980<h5>Semantics:</h5>
5981<p>
5982 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
5983 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
5984 equivalent of an atomic swap operation within the SSA framework.
5985
5986</p>
5987<h5>Examples:</h5>
5988<pre>
5989%ptr = malloc i32
5990 store i32 4, %ptr
5991
5992%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5993%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5994 <i>; yields {i32}:result1 = 4</i>
5995%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5996%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5997
5998%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5999%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6000 <i>; yields {i32}:result2 = 8</i>
6001
6002%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6003%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6004</pre>
6005</div>
6006
6007<!-- _______________________________________________________________________ -->
6008<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6009 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6010
6011</div>
6012<div class="doc_text">
6013<h5>Syntax:</h5>
6014<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6015 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]6016 integer bit width. Not all targets support all bit widths however.</p>
6017<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6018declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6019declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6020declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6021declare 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]6022
6023</pre>
6024<h5>Overview:</h5>
6025<p>
6026 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6027 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6028</p>
6029<h5>Arguments:</h5>
6030<p>
6031
6032 The intrinsic takes two arguments, the first a pointer to an integer value
6033 and the second an integer value. The result is also an integer value. These
6034 integer types can have any bit width, but they must all have the same bit
6035 width. The targets may only lower integer representations they support.
6036</p>
6037<h5>Semantics:</h5>
6038<p>
6039 This intrinsic does a series of operations atomically. It first loads the
6040 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6041 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6042</p>
6043
6044<h5>Examples:</h5>
6045<pre>
6046%ptr = malloc i32
6047 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6048%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6049 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6050%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6051 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6052%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6053 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6054%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6055</pre>
6056</div>
6057
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6058<!-- _______________________________________________________________________ -->
6059<div class="doc_subsubsection">
6060 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6061
6062</div>
6063<div class="doc_text">
6064<h5>Syntax:</h5>
6065<p>
6066 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]6067 any integer bit width and for different address spaces. Not all targets
6068 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6069<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6070declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6071declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6072declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6073declare 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]6074
6075</pre>
6076<h5>Overview:</h5>
6077<p>
6078 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6079 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6080</p>
6081<h5>Arguments:</h5>
6082<p>
6083
6084 The intrinsic takes two arguments, the first a pointer to an integer value
6085 and the second an integer value. The result is also an integer value. These
6086 integer types can have any bit width, but they must all have the same bit
6087 width. The targets may only lower integer representations they support.
6088</p>
6089<h5>Semantics:</h5>
6090<p>
6091 This intrinsic does a series of operations atomically. It first loads the
6092 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6093 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6094</p>
6095
6096<h5>Examples:</h5>
6097<pre>
6098%ptr = malloc i32
6099 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6100%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6101 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6102%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6103 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6104%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6105 <i>; yields {i32}:result3 = 2</i>
6106%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6107</pre>
6108</div>
6109
6110<!-- _______________________________________________________________________ -->
6111<div class="doc_subsubsection">
6112 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6113 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6114 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6115 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6116
6117</div>
6118<div class="doc_text">
6119<h5>Syntax:</h5>
6120<p>
6121 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6122 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6123 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6124 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6125<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6126declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6127declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6128declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6129declare 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]6130
6131</pre>
6132
6133<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6134declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6135declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6136declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6137declare 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]6138
6139</pre>
6140
6141<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6142declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6143declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6144declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6145declare 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]6146
6147</pre>
6148
6149<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6150declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6151declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6152declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6153declare 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]6154
6155</pre>
6156<h5>Overview:</h5>
6157<p>
6158 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6159 the value stored in memory at <tt>ptr</tt>. It yields the original value
6160 at <tt>ptr</tt>.
6161</p>
6162<h5>Arguments:</h5>
6163<p>
6164
6165 These intrinsics take two arguments, the first a pointer to an integer value
6166 and the second an integer value. The result is also an integer value. These
6167 integer types can have any bit width, but they must all have the same bit
6168 width. The targets may only lower integer representations they support.
6169</p>
6170<h5>Semantics:</h5>
6171<p>
6172 These intrinsics does a series of operations atomically. They first load the
6173 value stored at <tt>ptr</tt>. They then do the bitwise operation
6174 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6175 value stored at <tt>ptr</tt>.
6176</p>
6177
6178<h5>Examples:</h5>
6179<pre>
6180%ptr = malloc i32
6181 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6182%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6183 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6184%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6185 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6186%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6187 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6188%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6189 <i>; yields {i32}:result3 = FF</i>
6190%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6191</pre>
6192</div>
6193
6194
6195<!-- _______________________________________________________________________ -->
6196<div class="doc_subsubsection">
6197 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6198 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6199 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6200 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6201
6202</div>
6203<div class="doc_text">
6204<h5>Syntax:</h5>
6205<p>
6206 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6207 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6208 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6209 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6210 support all bit widths however.</p>
6211<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6212declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6213declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6214declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6215declare 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]6216
6217</pre>
6218
6219<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6220declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6221declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6222declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6223declare 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]6224
6225</pre>
6226
6227<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6228declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6229declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6230declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6231declare 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]6232
6233</pre>
6234
6235<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6236declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6237declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6238declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6239declare 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]6240
6241</pre>
6242<h5>Overview:</h5>
6243<p>
6244 These intrinsics takes the signed or unsigned minimum or maximum of
6245 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6246 original value at <tt>ptr</tt>.
6247</p>
6248<h5>Arguments:</h5>
6249<p>
6250
6251 These intrinsics take two arguments, the first a pointer to an integer value
6252 and the second an integer value. The result is also an integer value. These
6253 integer types can have any bit width, but they must all have the same bit
6254 width. The targets may only lower integer representations they support.
6255</p>
6256<h5>Semantics:</h5>
6257<p>
6258 These intrinsics does a series of operations atomically. They first load the
6259 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6260 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6261 the original value stored at <tt>ptr</tt>.
6262</p>
6263
6264<h5>Examples:</h5>
6265<pre>
6266%ptr = malloc i32
6267 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6268%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6269 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6270%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6271 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6272%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6273 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6274%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6275 <i>; yields {i32}:result3 = 8</i>
6276%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6277</pre>
6278</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6279
6280<!-- ======================================================================= -->
6281<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6282 <a name="int_general">General Intrinsics</a>
6283</div>
6284
6285<div class="doc_text">
6286<p> This class of intrinsics is designed to be generic and has
6287no specific purpose. </p>
6288</div>
6289
6290<!-- _______________________________________________________________________ -->
6291<div class="doc_subsubsection">
6292 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6293</div>
6294
6295<div class="doc_text">
6296
6297<h5>Syntax:</h5>
6298<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6299 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]6300</pre>
6301
6302<h5>Overview:</h5>
6303
6304<p>
6305The '<tt>llvm.var.annotation</tt>' intrinsic
6306</p>
6307
6308<h5>Arguments:</h5>
6309
6310<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6311The first argument is a pointer to a value, the second is a pointer to a
6312global string, the third is a pointer to a global string which is the source
6313file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6314</p>
6315
6316<h5>Semantics:</h5>
6317
6318<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6319This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6320This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6321annotations. These have no other defined use, they are ignored by code
6322generation and optimization.
6323</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6324</div>
6325
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6326<!-- _______________________________________________________________________ -->
6327<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6328 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6329</div>
6330
6331<div class="doc_text">
6332
6333<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6334<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6335any integer bit width.
6336</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6337<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6338 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6339 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6340 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6341 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6342 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]6343</pre>
6344
6345<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6346
6347<p>
6348The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6349</p>
6350
6351<h5>Arguments:</h5>
6352
6353<p>
6354The first argument is an integer value (result of some expression),
6355the second is a pointer to a global string, the third is a pointer to a global
6356string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6357It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6358</p>
6359
6360<h5>Semantics:</h5>
6361
6362<p>
6363This intrinsic allows annotations to be put on arbitrary expressions
6364with arbitrary strings. This can be useful for special purpose optimizations
6365that want to look for these annotations. These have no other defined use, they
6366are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame^]6367</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6368</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6369
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6370<!-- _______________________________________________________________________ -->
6371<div class="doc_subsubsection">
6372 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6373</div>
6374
6375<div class="doc_text">
6376
6377<h5>Syntax:</h5>
6378<pre>
6379 declare void @llvm.trap()
6380</pre>
6381
6382<h5>Overview:</h5>
6383
6384<p>
6385The '<tt>llvm.trap</tt>' intrinsic
6386</p>
6387
6388<h5>Arguments:</h5>
6389
6390<p>
6391None
6392</p>
6393
6394<h5>Semantics:</h5>
6395
6396<p>
6397This intrinsics is lowered to the target dependent trap instruction. If the
6398target does not have a trap instruction, this intrinsic will be lowered to the
6399call of the abort() function.
6400</p>
6401</div>
6402
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6403<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6404<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6405<address>
6406 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6407 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6408 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6409 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6410
6411 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6412 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6413 Last modified: $Date$
6414</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6415
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6416</body>
6417</html>