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gerrit-public.fairphone.software / toolchain / llvm-project / 0f8155ae4e2cb08bf52c94fec1c73393c16bc708 / . / 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
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame^]338 with quotes. Special characters may be escaped using "\xx" where xx is the
339 ASCII code for the character in hexadecimal. In this way, any character can
340 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]341
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]342 <li>Unnamed values are represented as an unsigned numeric value with their
343 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]344
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]345 <li>Constants, which are described in a <a href="#constants">section about
346 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]347</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]348
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]349<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]350don't need to worry about name clashes with reserved words, and the set of
351reserved words may be expanded in the future without penalty. Additionally,
352unnamed identifiers allow a compiler to quickly come up with a temporary
353variable without having to avoid symbol table conflicts.</p>
354
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]355<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]356languages. There are keywords for different opcodes
357('<tt><a href="#i_add">add</a></tt>',
358 '<tt><a href="#i_bitcast">bitcast</a></tt>',
359 '<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]360href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]361and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]362none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]363
364<p>Here is an example of LLVM code to multiply the integer variable
365'<tt>%X</tt>' by 8:</p>
366
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]367<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]368
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]369<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]370<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]371%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]372</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]373</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]375<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]378<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]379%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]380</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]381</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]382
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]383<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]384
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]385<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]386<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]387<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
388<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
389%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]390</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]391</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]392
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]393<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
394important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]395
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]396<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]397
398 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
399 line.</li>
400
401 <li>Unnamed temporaries are created when the result of a computation is not
402 assigned to a named value.</li>
403
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]404 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]406</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]407
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]408<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409demonstrating instructions, we will follow an instruction with a comment that
410defines the type and name of value produced. Comments are shown in italic
411text.</p>
412
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]413</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]414
415<!-- *********************************************************************** -->
416<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
417<!-- *********************************************************************** -->
418
419<!-- ======================================================================= -->
420<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
421</div>
422
423<div class="doc_text">
424
425<p>LLVM programs are composed of "Module"s, each of which is a
426translation unit of the input programs. Each module consists of
427functions, global variables, and symbol table entries. Modules may be
428combined together with the LLVM linker, which merges function (and
429global variable) definitions, resolves forward declarations, and merges
430symbol table entries. Here is an example of the "hello world" module:</p>
431
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]432<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]433<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]434<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
435 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]436
437<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]438<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]439
440<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]441define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]442 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]443 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]444 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]445
446 <i>; Call puts function to write out the string to stdout...</i>
447 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]448 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]449 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]450 href="#i_ret">ret</a> i32 0<br>}<br>
451</pre>
452</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]453
454<p>This example is made up of a <a href="#globalvars">global variable</a>
455named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
456function, and a <a href="#functionstructure">function definition</a>
457for "<tt>main</tt>".</p>
458
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459<p>In general, a module is made up of a list of global values,
460where both functions and global variables are global values. Global values are
461represented by a pointer to a memory location (in this case, a pointer to an
462array of char, and a pointer to a function), and have one of the following <a
463href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]464
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465</div>
466
467<!-- ======================================================================= -->
468<div class="doc_subsection">
469 <a name="linkage">Linkage Types</a>
470</div>
471
472<div class="doc_text">
473
474<p>
475All Global Variables and Functions have one of the following types of linkage:
476</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]477
478<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]479
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]480 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]481
482 <dd>Global values with internal linkage are only directly accessible by
483 objects in the current module. In particular, linking code into a module with
484 an internal global value may cause the internal to be renamed as necessary to
485 avoid collisions. Because the symbol is internal to the module, all
486 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]487 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]488 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]489
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]490 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]491
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]492 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
493 the same name when linkage occurs. This is typically used to implement
494 inline functions, templates, or other code which must be generated in each
495 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
496 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]497 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]498
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]499 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
500
501 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
502 linkage, except that unreferenced <tt>common</tt> globals may not be
503 discarded. This is used for globals that may be emitted in multiple
504 translation units, but that are not guaranteed to be emitted into every
505 translation unit that uses them. One example of this is tentative
506 definitions in C, such as "<tt>int X;</tt>" at global scope.
507 </dd>
508
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]509 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]510
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]511 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
512 that some targets may choose to emit different assembly sequences for them
513 for target-dependent reasons. This is used for globals that are declared
514 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]515 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]516
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]517 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]518
519 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
520 pointer to array type. When two global variables with appending linkage are
521 linked together, the two global arrays are appended together. This is the
522 LLVM, typesafe, equivalent of having the system linker append together
523 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]524 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]525
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]526 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]527 <dd>The semantics of this linkage follow the ELF object file model: the
528 symbol is weak until linked, if not linked, the symbol becomes null instead
529 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]530 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]531
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]532 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]533
534 <dd>If none of the above identifiers are used, the global is externally
535 visible, meaning that it participates in linkage and can be used to resolve
536 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]537 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]538</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]539
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]540 <p>
541 The next two types of linkage are targeted for Microsoft Windows platform
542 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]543 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]544 </p>
545
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]546 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
548
549 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
550 or variable via a global pointer to a pointer that is set up by the DLL
551 exporting the symbol. On Microsoft Windows targets, the pointer name is
552 formed by combining <code>_imp__</code> and the function or variable name.
553 </dd>
554
555 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
556
557 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
558 pointer to a pointer in a DLL, so that it can be referenced with the
559 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
560 name is formed by combining <code>_imp__</code> and the function or variable
561 name.
562 </dd>
563
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]564</dl>
565
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]566<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]567variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
568variable and was linked with this one, one of the two would be renamed,
569preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
570external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]571outside of the current module.</p>
572<p>It is illegal for a function <i>declaration</i>
573to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]574or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]575<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]576linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]577</div>
578
579<!-- ======================================================================= -->
580<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]581 <a name="callingconv">Calling Conventions</a>
582</div>
583
584<div class="doc_text">
585
586<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
587and <a href="#i_invoke">invokes</a> can all have an optional calling convention
588specified for the call. The calling convention of any pair of dynamic
589caller/callee must match, or the behavior of the program is undefined. The
590following calling conventions are supported by LLVM, and more may be added in
591the future:</p>
592
593<dl>
594 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
595
596 <dd>This calling convention (the default if no other calling convention is
597 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]598 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]599 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]600 </dd>
601
602 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
603
604 <dd>This calling convention attempts to make calls as fast as possible
605 (e.g. by passing things in registers). This calling convention allows the
606 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]607 without having to conform to an externally specified ABI (Application Binary
608 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]609 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
610 supported. This calling convention does not support varargs and requires the
611 prototype of all callees to exactly match the prototype of the function
612 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]613 </dd>
614
615 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
616
617 <dd>This calling convention attempts to make code in the caller as efficient
618 as possible under the assumption that the call is not commonly executed. As
619 such, these calls often preserve all registers so that the call does not break
620 any live ranges in the caller side. This calling convention does not support
621 varargs and requires the prototype of all callees to exactly match the
622 prototype of the function definition.
623 </dd>
624
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]625 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]626
627 <dd>Any calling convention may be specified by number, allowing
628 target-specific calling conventions to be used. Target specific calling
629 conventions start at 64.
630 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]631</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]632
633<p>More calling conventions can be added/defined on an as-needed basis, to
634support pascal conventions or any other well-known target-independent
635convention.</p>
636
637</div>
638
639<!-- ======================================================================= -->
640<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]641 <a name="visibility">Visibility Styles</a>
642</div>
643
644<div class="doc_text">
645
646<p>
647All Global Variables and Functions have one of the following visibility styles:
648</p>
649
650<dl>
651 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
652
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]653 <dd>On targets that use the ELF object file format, default visibility means
654 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]655 modules and, in shared libraries, means that the declared entity may be
656 overridden. On Darwin, default visibility means that the declaration is
657 visible to other modules. Default visibility corresponds to "external
658 linkage" in the language.
659 </dd>
660
661 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
662
663 <dd>Two declarations of an object with hidden visibility refer to the same
664 object if they are in the same shared object. Usually, hidden visibility
665 indicates that the symbol will not be placed into the dynamic symbol table,
666 so no other module (executable or shared library) can reference it
667 directly.
668 </dd>
669
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]670 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
671
672 <dd>On ELF, protected visibility indicates that the symbol will be placed in
673 the dynamic symbol table, but that references within the defining module will
674 bind to the local symbol. That is, the symbol cannot be overridden by another
675 module.
676 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]677</dl>
678
679</div>
680
681<!-- ======================================================================= -->
682<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]683 <a name="globalvars">Global Variables</a>
684</div>
685
686<div class="doc_text">
687
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]688<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]689instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]690an explicit section to be placed in, and may have an optional explicit alignment
691specified. A variable may be defined as "thread_local", which means that it
692will not be shared by threads (each thread will have a separated copy of the
693variable). A variable may be defined as a global "constant," which indicates
694that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]695optimization, allowing the global data to be placed in the read-only section of
696an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]697cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]698
699<p>
700LLVM explicitly allows <em>declarations</em> of global variables to be marked
701constant, even if the final definition of the global is not. This capability
702can be used to enable slightly better optimization of the program, but requires
703the language definition to guarantee that optimizations based on the
704'constantness' are valid for the translation units that do not include the
705definition.
706</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]707
708<p>As SSA values, global variables define pointer values that are in
709scope (i.e. they dominate) all basic blocks in the program. Global
710variables always define a pointer to their "content" type because they
711describe a region of memory, and all memory objects in LLVM are
712accessed through pointers.</p>
713
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]714<p>A global variable may be declared to reside in a target-specifc numbered
715address space. For targets that support them, address spaces may affect how
716optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]717the variable. The default address space is zero. The address space qualifier
718must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]719
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]720<p>LLVM allows an explicit section to be specified for globals. If the target
721supports it, it will emit globals to the section specified.</p>
722
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]723<p>An explicit alignment may be specified for a global. If not present, or if
724the alignment is set to zero, the alignment of the global is set by the target
725to whatever it feels convenient. If an explicit alignment is specified, the
726global is forced to have at least that much alignment. All alignments must be
727a power of 2.</p>
728
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]729<p>For example, the following defines a global in a numbered address space with
730an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]731
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]732<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]733<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]734@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]735</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]736</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]737
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]738</div>
739
740
741<!-- ======================================================================= -->
742<div class="doc_subsection">
743 <a name="functionstructure">Functions</a>
744</div>
745
746<div class="doc_text">
747
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]748<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
749an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]750<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]751<a href="#callingconv">calling convention</a>, a return type, an optional
752<a href="#paramattrs">parameter attribute</a> for the return type, a function
753name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]754<a href="#paramattrs">parameter attributes</a>), optional
755<a href="#fnattrs">function attributes</a>, an optional section,
756an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]757an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]758
759LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
760optional <a href="#linkage">linkage type</a>, an optional
761<a href="#visibility">visibility style</a>, an optional
762<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]763<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]764name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]765<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]766
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]767<p>A function definition contains a list of basic blocks, forming the CFG
768(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]769the function. Each basic block may optionally start with a label (giving the
770basic block a symbol table entry), contains a list of instructions, and ends
771with a <a href="#terminators">terminator</a> instruction (such as a branch or
772function return).</p>
773
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]774<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]775executed on entrance to the function, and it is not allowed to have predecessor
776basic blocks (i.e. there can not be any branches to the entry block of a
777function). Because the block can have no predecessors, it also cannot have any
778<a href="#i_phi">PHI nodes</a>.</p>
779
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]780<p>LLVM allows an explicit section to be specified for functions. If the target
781supports it, it will emit functions to the section specified.</p>
782
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]783<p>An explicit alignment may be specified for a function. If not present, or if
784the alignment is set to zero, the alignment of the function is set by the target
785to whatever it feels convenient. If an explicit alignment is specified, the
786function is forced to have at least that much alignment. All alignments must be
787a power of 2.</p>
788
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]789 <h5>Syntax:</h5>
790
791<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]792<tt>
793define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
794 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
795 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
796 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
797 [<a href="#gc">gc</a>] { ... }
798</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]799</div>
800
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]801</div>
802
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]803
804<!-- ======================================================================= -->
805<div class="doc_subsection">
806 <a name="aliasstructure">Aliases</a>
807</div>
808<div class="doc_text">
809 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]810 function, global variable, another alias or bitcast of global value). Aliases
811 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]812 optional <a href="#visibility">visibility style</a>.</p>
813
814 <h5>Syntax:</h5>
815
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]816<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]817<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]818@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]819</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]820</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]821
822</div>
823
824
825
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]826<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]827<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
828<div class="doc_text">
829 <p>The return type and each parameter of a function type may have a set of
830 <i>parameter attributes</i> associated with them. Parameter attributes are
831 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]832 a function. Parameter attributes are considered to be part of the function,
833 not of the function type, so functions with different parameter attributes
834 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]835
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]836 <p>Parameter attributes are simple keywords that follow the type specified. If
837 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]838 example:</p>
839
840<div class="doc_code">
841<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]842declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]843declare i32 @atoi(i8 zeroext)
844declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]845</pre>
846</div>
847
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]848 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
849 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]850
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]851 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]852 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]853 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]854 <dd>This indicates to the code generator that the parameter or return value
855 should be zero-extended to a 32-bit value by the caller (for a parameter)
856 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]857
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]858 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]859 <dd>This indicates to the code generator that the parameter or return value
860 should be sign-extended to a 32-bit value by the caller (for a parameter)
861 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]862
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]863 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]864 <dd>This indicates that this parameter or return value should be treated
865 in a special target-dependent fashion during while emitting code for a
866 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]867 to memory, though some targets use it to distinguish between two different
868 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]869
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]870 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]871 <dd>This indicates that the pointer parameter should really be passed by
872 value to the function. The attribute implies that a hidden copy of the
873 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]874 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]875 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]876 value, but is also valid on pointers to scalars. The copy is considered to
877 belong to the caller not the callee (for example,
878 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]879 <tt>byval</tt> parameters). This is not a valid attribute for return
880 values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]881
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]882 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]883 <dd>This indicates that the pointer parameter specifies the address of a
884 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]885 This pointer must be guaranteed by the caller to be valid: loads and stores
886 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]887 be applied to the first parameter. This is not a valid attribute for
888 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]889
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]890 <dt><tt>noalias</tt></dt>
Owen Anderson61101282008-02-18 04:09:01 +0000[diff] [blame]891 <dd>This indicates that the parameter does not alias any global or any other
892 parameter. The caller is responsible for ensuring that this is the case,
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]893 usually by placing the value in a stack allocation. This is not a valid
894 attribute for return values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]895
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]896 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]897 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]898 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
899 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]900 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]901
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]902</div>
903
904<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]905<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]906 <a name="gc">Garbage Collector Names</a>
907</div>
908
909<div class="doc_text">
910<p>Each function may specify a garbage collector name, which is simply a
911string.</p>
912
913<div class="doc_code"><pre
914>define void @f() gc "name" { ...</pre></div>
915
916<p>The compiler declares the supported values of <i>name</i>. Specifying a
917collector which will cause the compiler to alter its output in order to support
918the named garbage collection algorithm.</p>
919</div>
920
921<!-- ======================================================================= -->
922<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]923 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]924</div>
925
926<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]927
928<p>Function attributes are set to communicate additional information about
929 a function. Function attributes are considered to be part of the function,
930 not of the function type, so functions with different parameter attributes
931 can have the same function type.</p>
932
933 <p>Function attributes are simple keywords that follow the type specified. If
934 multiple attributes are needed, they are space separated. For
935 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]936
937<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]938<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]939define void @f() noinline { ... }
940define void @f() alwaysinline { ... }
941define void @f() alwaysinline optsize { ... }
942define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]943</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]944</div>
945
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]946<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]947<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]948<dd>This attribute indicates that the inliner should attempt to inline this
949function into callers whenever possible, ignoring any active inlining size
950threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]951
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]952<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]953<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]954in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]955<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]956
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]957<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]958<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]959make choices that keep the code size of this function low, and otherwise do
960optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]961
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]962<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]963<dd>This function attribute indicates that the function never returns normally.
964This produces undefined behavior at runtime if the function ever does
965dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]966
967<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]968<dd>This function attribute indicates that the function never returns with an
969unwind or exceptional control flow. If the function does unwind, its runtime
970behavior is undefined.</dd>
971
972<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]973<dd>This attribute indicates that the function computes its result (or the
974exception it throws) based strictly on its arguments, without dereferencing any
975pointer arguments or otherwise accessing any mutable state (e.g. memory, control
976registers, etc) visible to caller functions. It does not write through any
977pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
978never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]979
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]980<dt><tt><a name="readonly">readonly</a></tt></dt>
981<dd>This attribute indicates that the function does not write through any
982pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
983or otherwise modify any state (e.g. memory, control registers, etc) visible to
984caller functions. It may dereference pointer arguments and read state that may
985be set in the caller. A readonly function always returns the same value (or
986throws the same exception) when called with the same set of arguments and global
987state.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]988</dl>
989
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]990</div>
991
992<!-- ======================================================================= -->
993<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]994 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]995</div>
996
997<div class="doc_text">
998<p>
999Modules may contain "module-level inline asm" blocks, which corresponds to the
1000GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1001LLVM and treated as a single unit, but may be separated in the .ll file if
1002desired. The syntax is very simple:
1003</p>
1004
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1005<div class="doc_code">
1006<pre>
1007module asm "inline asm code goes here"
1008module asm "more can go here"
1009</pre>
1010</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1011
1012<p>The strings can contain any character by escaping non-printable characters.
1013 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1014 for the number.
1015</p>
1016
1017<p>
1018 The inline asm code is simply printed to the machine code .s file when
1019 assembly code is generated.
1020</p>
1021</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1022
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1023<!-- ======================================================================= -->
1024<div class="doc_subsection">
1025 <a name="datalayout">Data Layout</a>
1026</div>
1027
1028<div class="doc_text">
1029<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1030data is to be laid out in memory. The syntax for the data layout is simply:</p>
1031<pre> target datalayout = "<i>layout specification</i>"</pre>
1032<p>The <i>layout specification</i> consists of a list of specifications
1033separated by the minus sign character ('-'). Each specification starts with a
1034letter and may include other information after the letter to define some
1035aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1036<dl>
1037 <dt><tt>E</tt></dt>
1038 <dd>Specifies that the target lays out data in big-endian form. That is, the
1039 bits with the most significance have the lowest address location.</dd>
1040 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1041 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1042 the bits with the least significance have the lowest address location.</dd>
1043 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1044 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1045 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1046 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1047 too.</dd>
1048 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1049 <dd>This specifies the alignment for an integer type of a given bit
1050 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1051 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1052 <dd>This specifies the alignment for a vector type of a given bit
1053 <i>size</i>.</dd>
1054 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1055 <dd>This specifies the alignment for a floating point type of a given bit
1056 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1057 (double).</dd>
1058 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1059 <dd>This specifies the alignment for an aggregate type of a given bit
1060 <i>size</i>.</dd>
1061</dl>
1062<p>When constructing the data layout for a given target, LLVM starts with a
1063default set of specifications which are then (possibly) overriden by the
1064specifications in the <tt>datalayout</tt> keyword. The default specifications
1065are given in this list:</p>
1066<ul>
1067 <li><tt>E</tt> - big endian</li>
1068 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1069 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1070 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1071 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1072 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1073 <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]1074 alignment of 64-bits</li>
1075 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1076 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1077 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1078 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1079 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1080</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1081<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1082following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1083<ol>
1084 <li>If the type sought is an exact match for one of the specifications, that
1085 specification is used.</li>
1086 <li>If no match is found, and the type sought is an integer type, then the
1087 smallest integer type that is larger than the bitwidth of the sought type is
1088 used. If none of the specifications are larger than the bitwidth then the the
1089 largest integer type is used. For example, given the default specifications
1090 above, the i7 type will use the alignment of i8 (next largest) while both
1091 i65 and i256 will use the alignment of i64 (largest specified).</li>
1092 <li>If no match is found, and the type sought is a vector type, then the
1093 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1094 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1095 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1096</ol>
1097</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1098
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1099<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1100<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1101<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1102
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1103<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1104
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1105<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1106intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1107optimizations to be performed on the intermediate representation directly,
1108without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1109extra analyses on the side before the transformation. A strong type
1110system makes it easier to read the generated code and enables novel
1111analyses and transformations that are not feasible to perform on normal
1112three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1113
1114</div>
1115
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1116<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1117<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1118Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1119<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1120<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1121classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1122
1123<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1124 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1125 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1126 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1127 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1128 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1129 </tr>
1130 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1131 <td><a href="#t_floating">floating point</a></td>
1132 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1133 </tr>
1134 <tr>
1135 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1136 <td><a href="#t_integer">integer</a>,
1137 <a href="#t_floating">floating point</a>,
1138 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1139 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1140 <a href="#t_struct">structure</a>,
1141 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1142 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1143 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1144 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1145 <tr>
1146 <td><a href="#t_primitive">primitive</a></td>
1147 <td><a href="#t_label">label</a>,
1148 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1149 <a href="#t_floating">floating point</a>.</td>
1150 </tr>
1151 <tr>
1152 <td><a href="#t_derived">derived</a></td>
1153 <td><a href="#t_integer">integer</a>,
1154 <a href="#t_array">array</a>,
1155 <a href="#t_function">function</a>,
1156 <a href="#t_pointer">pointer</a>,
1157 <a href="#t_struct">structure</a>,
1158 <a href="#t_pstruct">packed structure</a>,
1159 <a href="#t_vector">vector</a>,
1160 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1161 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1162 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1163 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1164</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1165
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1166<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1167most important. Values of these types are the only ones which can be
1168produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1169instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1170</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1171
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1172<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1173<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1174
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1175<div class="doc_text">
1176<p>The primitive types are the fundamental building blocks of the LLVM
1177system.</p>
1178
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1179</div>
1180
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1181<!-- _______________________________________________________________________ -->
1182<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1183
1184<div class="doc_text">
1185 <table>
1186 <tbody>
1187 <tr><th>Type</th><th>Description</th></tr>
1188 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1189 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1190 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1191 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1192 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1193 </tbody>
1194 </table>
1195</div>
1196
1197<!-- _______________________________________________________________________ -->
1198<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1199
1200<div class="doc_text">
1201<h5>Overview:</h5>
1202<p>The void type does not represent any value and has no size.</p>
1203
1204<h5>Syntax:</h5>
1205
1206<pre>
1207 void
1208</pre>
1209</div>
1210
1211<!-- _______________________________________________________________________ -->
1212<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1213
1214<div class="doc_text">
1215<h5>Overview:</h5>
1216<p>The label type represents code labels.</p>
1217
1218<h5>Syntax:</h5>
1219
1220<pre>
1221 label
1222</pre>
1223</div>
1224
1225
1226<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1227<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1228
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1229<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1230
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1231<p>The real power in LLVM comes from the derived types in the system.
1232This is what allows a programmer to represent arrays, functions,
1233pointers, and other useful types. Note that these derived types may be
1234recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1235
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1236</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1237
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1238<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1239<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1240
1241<div class="doc_text">
1242
1243<h5>Overview:</h5>
1244<p>The integer type is a very simple derived type that simply specifies an
1245arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12462^23-1 (about 8 million) can be specified.</p>
1247
1248<h5>Syntax:</h5>
1249
1250<pre>
1251 iN
1252</pre>
1253
1254<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1255value.</p>
1256
1257<h5>Examples:</h5>
1258<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1259 <tbody>
1260 <tr>
1261 <td><tt>i1</tt></td>
1262 <td>a single-bit integer.</td>
1263 </tr><tr>
1264 <td><tt>i32</tt></td>
1265 <td>a 32-bit integer.</td>
1266 </tr><tr>
1267 <td><tt>i1942652</tt></td>
1268 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1269 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1270 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1271</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1272</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1273
1274<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1275<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1276
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1277<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1278
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1279<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1280
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1281<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1282sequentially in memory. The array type requires a size (number of
1283elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1284
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1285<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1286
1287<pre>
1288 [&lt;# elements&gt; x &lt;elementtype&gt;]
1289</pre>
1290
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1291<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1292be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1293
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1294<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1295<table class="layout">
1296 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1297 <td class="left"><tt>[40 x i32]</tt></td>
1298 <td class="left">Array of 40 32-bit integer values.</td>
1299 </tr>
1300 <tr class="layout">
1301 <td class="left"><tt>[41 x i32]</tt></td>
1302 <td class="left">Array of 41 32-bit integer values.</td>
1303 </tr>
1304 <tr class="layout">
1305 <td class="left"><tt>[4 x i8]</tt></td>
1306 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1307 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1308</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1309<p>Here are some examples of multidimensional arrays:</p>
1310<table class="layout">
1311 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1312 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1313 <td class="left">3x4 array of 32-bit integer values.</td>
1314 </tr>
1315 <tr class="layout">
1316 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1317 <td class="left">12x10 array of single precision floating point values.</td>
1318 </tr>
1319 <tr class="layout">
1320 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1321 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1322 </tr>
1323</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1324
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1325<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1326length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1327LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1328As a special case, however, zero length arrays are recognized to be variable
1329length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1330type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1331
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1332</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1333
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1334<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1335<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1336<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1338<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1339
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1340<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1341consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1342return 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]1343If 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]1344class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1345
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1346<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1347
1348<pre>
1349 &lt;returntype list&gt; (&lt;parameter list&gt;)
1350</pre>
1351
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1352<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]1353specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1354which indicates that the function takes a variable number of arguments.
1355Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1356 href="#int_varargs">variable argument handling intrinsic</a> functions.
1357'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1358<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1359
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1360<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1361<table class="layout">
1362 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1363 <td class="left"><tt>i32 (i32)</tt></td>
1364 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1365 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1366 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1367 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1368 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1369 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1370 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1371 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1372 <tt>float</tt>.
1373 </td>
1374 </tr><tr class="layout">
1375 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1376 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1377 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1378 which returns an integer. This is the signature for <tt>printf</tt> in
1379 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1380 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1381 </tr><tr class="layout">
1382 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel8dec6c22008-03-24 18:10:52 +0000[diff] [blame]1383 <td class="left">A function taking an <tt>i32></tt>, returning two
1384 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1385 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1386 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1387</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1388
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1389</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1390<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1391<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1392<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1393<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1394<p>The structure type is used to represent a collection of data members
1395together in memory. The packing of the field types is defined to match
1396the ABI of the underlying processor. The elements of a structure may
1397be any type that has a size.</p>
1398<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1399and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1400field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1401instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1402<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1403<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1404<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1405<table class="layout">
1406 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1407 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1408 <td class="left">A triple of three <tt>i32</tt> values</td>
1409 </tr><tr class="layout">
1410 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1411 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1412 second element is a <a href="#t_pointer">pointer</a> to a
1413 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1414 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1415 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1416</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1417</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1418
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1419<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1420<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1421</div>
1422<div class="doc_text">
1423<h5>Overview:</h5>
1424<p>The packed structure type is used to represent a collection of data members
1425together in memory. There is no padding between fields. Further, the alignment
1426of a packed structure is 1 byte. The elements of a packed structure may
1427be any type that has a size.</p>
1428<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1429and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1430field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1431instruction.</p>
1432<h5>Syntax:</h5>
1433<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1434<h5>Examples:</h5>
1435<table class="layout">
1436 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1437 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1438 <td class="left">A triple of three <tt>i32</tt> values</td>
1439 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1440 <td class="left">
1441<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1442 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1443 second element is a <a href="#t_pointer">pointer</a> to a
1444 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1445 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1446 </tr>
1447</table>
1448</div>
1449
1450<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1451<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1452<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1453<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1454<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1455reference to another object, which must live in memory. Pointer types may have
1456an optional address space attribute defining the target-specific numbered
1457address space where the pointed-to object resides. The default address space is
1458zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1459<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1460<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1461<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1462<table class="layout">
1463 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1464 <td class="left"><tt>[4x i32]*</tt></td>
1465 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1466 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1467 </tr>
1468 <tr class="layout">
1469 <td class="left"><tt>i32 (i32 *) *</tt></td>
1470 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1471 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1472 <tt>i32</tt>.</td>
1473 </tr>
1474 <tr class="layout">
1475 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1476 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1477 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1478 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1479</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1480</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1481
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1482<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1483<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1484<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1485
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1486<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1487
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1488<p>A vector type is a simple derived type that represents a vector
1489of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1490are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1491A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1492elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1493of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1494considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1495
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1496<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1497
1498<pre>
1499 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1500</pre>
1501
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1502<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1503be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1504
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1505<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1506
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1507<table class="layout">
1508 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1509 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1510 <td class="left">Vector of 4 32-bit integer values.</td>
1511 </tr>
1512 <tr class="layout">
1513 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1514 <td class="left">Vector of 8 32-bit floating-point values.</td>
1515 </tr>
1516 <tr class="layout">
1517 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1518 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1519 </tr>
1520</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1521</div>
1522
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1523<!-- _______________________________________________________________________ -->
1524<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1525<div class="doc_text">
1526
1527<h5>Overview:</h5>
1528
1529<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1530corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1531In LLVM, opaque types can eventually be resolved to any type (not just a
1532structure type).</p>
1533
1534<h5>Syntax:</h5>
1535
1536<pre>
1537 opaque
1538</pre>
1539
1540<h5>Examples:</h5>
1541
1542<table class="layout">
1543 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1544 <td class="left"><tt>opaque</tt></td>
1545 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1546 </tr>
1547</table>
1548</div>
1549
1550
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1551<!-- *********************************************************************** -->
1552<div class="doc_section"> <a name="constants">Constants</a> </div>
1553<!-- *********************************************************************** -->
1554
1555<div class="doc_text">
1556
1557<p>LLVM has several different basic types of constants. This section describes
1558them all and their syntax.</p>
1559
1560</div>
1561
1562<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1563<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1564
1565<div class="doc_text">
1566
1567<dl>
1568 <dt><b>Boolean constants</b></dt>
1569
1570 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1571 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1572 </dd>
1573
1574 <dt><b>Integer constants</b></dt>
1575
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1576 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1577 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1578 integer types.
1579 </dd>
1580
1581 <dt><b>Floating point constants</b></dt>
1582
1583 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1584 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1585 notation (see below). The assembler requires the exact decimal value of
1586 a floating-point constant. For example, the assembler accepts 1.25 but
1587 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1588 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1589
1590 <dt><b>Null pointer constants</b></dt>
1591
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1592 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1593 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1594
1595</dl>
1596
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1597<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1598of floating point constants. For example, the form '<tt>double
15990x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16004.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1601(and the only time that they are generated by the disassembler) is when a
1602floating point constant must be emitted but it cannot be represented as a
1603decimal floating point number. For example, NaN's, infinities, and other
1604special values are represented in their IEEE hexadecimal format so that
1605assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1606
1607</div>
1608
1609<!-- ======================================================================= -->
1610<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1611</div>
1612
1613<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1614<p>Aggregate constants arise from aggregation of simple constants
1615and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1616
1617<dl>
1618 <dt><b>Structure constants</b></dt>
1619
1620 <dd>Structure constants are represented with notation similar to structure
1621 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1622 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1623 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]1624 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1625 types of elements must match those specified by the type.
1626 </dd>
1627
1628 <dt><b>Array constants</b></dt>
1629
1630 <dd>Array constants are represented with notation similar to array type
1631 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1632 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1633 constants must have <a href="#t_array">array type</a>, and the number and
1634 types of elements must match those specified by the type.
1635 </dd>
1636
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1637 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1638
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1639 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1640 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1641 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]1642 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1643 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1644 match those specified by the type.
1645 </dd>
1646
1647 <dt><b>Zero initialization</b></dt>
1648
1649 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1650 value to zero of <em>any</em> type, including scalar and aggregate types.
1651 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]1652 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1653 initializers.
1654 </dd>
1655</dl>
1656
1657</div>
1658
1659<!-- ======================================================================= -->
1660<div class="doc_subsection">
1661 <a name="globalconstants">Global Variable and Function Addresses</a>
1662</div>
1663
1664<div class="doc_text">
1665
1666<p>The addresses of <a href="#globalvars">global variables</a> and <a
1667href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1668constants. These constants are explicitly referenced when the <a
1669href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1670href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1671file:</p>
1672
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1673<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1674<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1675@X = global i32 17
1676@Y = global i32 42
1677@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1678</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1679</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1680
1681</div>
1682
1683<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1684<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1685<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1686 <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]1687 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1688 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1689
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1690 <p>Undefined values indicate to the compiler that the program is well defined
1691 no matter what value is used, giving the compiler more freedom to optimize.
1692 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1693</div>
1694
1695<!-- ======================================================================= -->
1696<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1697</div>
1698
1699<div class="doc_text">
1700
1701<p>Constant expressions are used to allow expressions involving other constants
1702to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1703href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1704that does not have side effects (e.g. load and call are not supported). The
1705following is the syntax for constant expressions:</p>
1706
1707<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1708 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1709 <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]1710 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1711
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1712 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1713 <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]1714 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]1715
1716 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1717 <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]1718 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]1719
1720 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1721 <dd>Truncate a floating point constant to another floating point type. The
1722 size of CST must be larger than the size of TYPE. Both types must be
1723 floating point.</dd>
1724
1725 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1726 <dd>Floating point extend a constant to another type. The size of CST must be
1727 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1728
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1729 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1730 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1731 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1732 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1733 of the same number of elements. If the value won't fit in the integer type,
1734 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1735
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1736 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1737 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1738 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1739 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1740 of the same number of elements. If the value won't fit in the integer type,
1741 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1742
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1743 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1744 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1745 constant. TYPE must be a scalar or vector floating point type. CST must be of
1746 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1747 of the same number of elements. If the value won't fit in the floating point
1748 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1749
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1750 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1751 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1752 constant. TYPE must be a scalar or vector floating point type. CST must be of
1753 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1754 of the same number of elements. If the value won't fit in the floating point
1755 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1756
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1757 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1758 <dd>Convert a pointer typed constant to the corresponding integer constant
1759 TYPE must be an integer type. CST must be of pointer type. The CST value is
1760 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1761
1762 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1763 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1764 pointer type. CST must be of integer type. The CST value is zero extended,
1765 truncated, or unchanged to make it fit in a pointer size. This one is
1766 <i>really</i> dangerous!</dd>
1767
1768 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1769 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1770 identical (same number of bits). The conversion is done as if the CST value
1771 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]1772 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1773 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]1774 pointers it is only valid to cast to another pointer type. It is not valid
1775 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1776 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1777
1778 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1779
1780 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1781 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1782 instruction, the index list may have zero or more indexes, which are required
1783 to make sense for the type of "CSTPTR".</dd>
1784
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1785 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1786
1787 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1788 constants.</dd>
1789
1790 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1791 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1792
1793 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1794 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1795
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1796 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1797 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1798
1799 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1800 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1801
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1802 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1803
1804 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1805 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1806
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1807 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1808
1809 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1810 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1811
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1812
1813 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1814
1815 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1816 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1817
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1818 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1819
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1820 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1821 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1822 binary</a> operations. The constraints on operands are the same as those for
1823 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1824 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1825</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1826</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1827
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1828<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1829<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1830<!-- *********************************************************************** -->
1831
1832<!-- ======================================================================= -->
1833<div class="doc_subsection">
1834<a name="inlineasm">Inline Assembler Expressions</a>
1835</div>
1836
1837<div class="doc_text">
1838
1839<p>
1840LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1841Module-Level Inline Assembly</a>) through the use of a special value. This
1842value represents the inline assembler as a string (containing the instructions
1843to emit), a list of operand constraints (stored as a string), and a flag that
1844indicates whether or not the inline asm expression has side effects. An example
1845inline assembler expression is:
1846</p>
1847
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1848<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1849<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1850i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1851</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1852</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1853
1854<p>
1855Inline assembler expressions may <b>only</b> be used as the callee operand of
1856a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1857</p>
1858
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1859<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1860<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1861%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]1862</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1863</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1864
1865<p>
1866Inline asms with side effects not visible in the constraint list must be marked
1867as having side effects. This is done through the use of the
1868'<tt>sideeffect</tt>' keyword, like so:
1869</p>
1870
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1871<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1872<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1873call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1874</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1875</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1876
1877<p>TODO: The format of the asm and constraints string still need to be
1878documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]1879need to be documented). This is probably best done by reference to another
1880document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1881</p>
1882
1883</div>
1884
1885<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1886<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1887<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1888
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1889<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1890
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1891<p>The LLVM instruction set consists of several different
1892classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1893instructions</a>, <a href="#binaryops">binary instructions</a>,
1894<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1895 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1896instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1897
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1898</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1899
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1900<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1901<div class="doc_subsection"> <a name="terminators">Terminator
1902Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1903
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1904<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1905
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1906<p>As mentioned <a href="#functionstructure">previously</a>, every
1907basic block in a program ends with a "Terminator" instruction, which
1908indicates which block should be executed after the current block is
1909finished. These terminator instructions typically yield a '<tt>void</tt>'
1910value: they produce control flow, not values (the one exception being
1911the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1912<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1913 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1914instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1915the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1916 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1917 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1918
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1919</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1920
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1921<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1922<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1923Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1924<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1925<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1926<pre>
1927 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]1928 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1929</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1930
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1931<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1932
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1933<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1934optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1935<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1936returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1937control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1938
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1939<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1940
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1941<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1942the return value. The type of the return value must be a
1943'<a href="#t_firstclass">first class</a>' type.</p>
1944
1945<p>A function is not <a href="#wellformed">well formed</a> if
1946it it has a non-void return type and contains a '<tt>ret</tt>'
1947instruction with no return value or a return value with a type that
1948does not match its type, or if it has a void return type and contains
1949a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1950
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1951<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1952
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1953<p>When the '<tt>ret</tt>' instruction is executed, control flow
1954returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1955 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1956the instruction after the call. If the caller was an "<a
1957 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1958at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1959returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1960return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1961
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1962<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1963
1964<pre>
1965 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1966 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1967 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]1968</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1969</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1970<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1971<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1972<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1973<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1974<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]1975</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1976<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1977<p>The '<tt>br</tt>' instruction is used to cause control flow to
1978transfer to a different basic block in the current function. There are
1979two forms of this instruction, corresponding to a conditional branch
1980and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1981<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1982<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1983single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1984unconditional form of the '<tt>br</tt>' instruction takes a single
1985'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1986<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1987<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1988argument is evaluated. If the value is <tt>true</tt>, control flows
1989to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1990control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1991<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1992<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]1993 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]1994</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1995<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1996<div class="doc_subsubsection">
1997 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1998</div>
1999
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2000<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2001<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2002
2003<pre>
2004 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2005</pre>
2006
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2007<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2008
2009<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2010several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2011instruction, allowing a branch to occur to one of many possible
2012destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2013
2014
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2015<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2016
2017<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2018comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2019an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2020table is not allowed to contain duplicate constant entries.</p>
2021
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2022<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2023
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2024<p>The <tt>switch</tt> instruction specifies a table of values and
2025destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2026table is searched for the given value. If the value is found, control flow is
2027transfered to the corresponding destination; otherwise, control flow is
2028transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2029
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2030<h5>Implementation:</h5>
2031
2032<p>Depending on properties of the target machine and the particular
2033<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2034ways. For example, it could be generated as a series of chained conditional
2035branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2036
2037<h5>Example:</h5>
2038
2039<pre>
2040 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2041 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2042 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2043
2044 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2045 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2046
2047 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2048 switch i32 %val, label %otherwise [ i32 0, label %onzero
2049 i32 1, label %onone
2050 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2051</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2052</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2053
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2054<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2055<div class="doc_subsubsection">
2056 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2057</div>
2058
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2059<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2060
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2061<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2062
2063<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2064 &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]2065 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2066</pre>
2067
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2068<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2069
2070<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2071function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2072'<tt>normal</tt>' label or the
2073'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2074"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2075"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2076href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2077continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2078
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2079<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2080
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2081<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2082
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2083<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2084 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2085 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2086 convention</a> the call should use. If none is specified, the call defaults
2087 to using C calling conventions.
2088 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2089
2090 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2091 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2092 and '<tt>inreg</tt>' attributes are valid here.</li>
2093
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2094 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2095 function value being invoked. In most cases, this is a direct function
2096 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2097 an arbitrary pointer to function value.
2098 </li>
2099
2100 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2101 function to be invoked. </li>
2102
2103 <li>'<tt>function args</tt>': argument list whose types match the function
2104 signature argument types. If the function signature indicates the function
2105 accepts a variable number of arguments, the extra arguments can be
2106 specified. </li>
2107
2108 <li>'<tt>normal label</tt>': the label reached when the called function
2109 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2110
2111 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2112 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2113
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2114 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2115 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2116 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2117</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2118
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2119<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2120
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2121<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2122href="#i_call">call</a></tt>' instruction in most regards. The primary
2123difference is that it establishes an association with a label, which is used by
2124the runtime library to unwind the stack.</p>
2125
2126<p>This instruction is used in languages with destructors to ensure that proper
2127cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2128exception. Additionally, this is important for implementation of
2129'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2130
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2131<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2132<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2133 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2134 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2135 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2136 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2137</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2138</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2139
2140
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2141<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2142
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2143<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2144Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2145
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2146<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2147
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2148<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2149<pre>
2150 unwind
2151</pre>
2152
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2153<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2154
2155<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2156at the first callee in the dynamic call stack which used an <a
2157href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2158primarily used to implement exception handling.</p>
2159
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2160<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2161
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2162<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2163immediately halt. The dynamic call stack is then searched for the first <a
2164href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2165execution continues at the "exceptional" destination block specified by the
2166<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2167dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2168</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2169
2170<!-- _______________________________________________________________________ -->
2171
2172<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2173Instruction</a> </div>
2174
2175<div class="doc_text">
2176
2177<h5>Syntax:</h5>
2178<pre>
2179 unreachable
2180</pre>
2181
2182<h5>Overview:</h5>
2183
2184<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2185instruction is used to inform the optimizer that a particular portion of the
2186code is not reachable. This can be used to indicate that the code after a
2187no-return function cannot be reached, and other facts.</p>
2188
2189<h5>Semantics:</h5>
2190
2191<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2192</div>
2193
2194
2195
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2196<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2197<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2198<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2199<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2200program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2201produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2202multiple 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]2203The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2204<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2205</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2206<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2207<div class="doc_subsubsection">
2208 <a name="i_add">'<tt>add</tt>' Instruction</a>
2209</div>
2210
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2211<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2212
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2213<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2214
2215<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2216 &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]2217</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2218
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2219<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2220
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2221<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2222
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2223<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2224
2225<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2226 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2227 <a href="#t_vector">vector</a> values. Both arguments must have identical
2228 types.</p>
2229
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2230<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2231
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2232<p>The value produced is the integer or floating point sum of the two
2233operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2234
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2235<p>If an integer sum has unsigned overflow, the result returned is the
2236mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2237the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2238
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2239<p>Because LLVM integers use a two's complement representation, this
2240instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2241
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2242<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2243
2244<pre>
2245 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2246</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2247</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2248<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2249<div class="doc_subsubsection">
2250 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2251</div>
2252
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2253<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2255<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2256
2257<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2258 &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]2259</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2260
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2261<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2262
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2263<p>The '<tt>sub</tt>' instruction returns the difference of its two
2264operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2265
2266<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2267'<tt>neg</tt>' instruction present in most other intermediate
2268representations.</p>
2269
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2270<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2271
2272<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2273 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2274 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2275 types.</p>
2276
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2277<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2278
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2279<p>The value produced is the integer or floating point difference of
2280the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2281
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2282<p>If an integer difference has unsigned overflow, the result returned is the
2283mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2284the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2285
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2286<p>Because LLVM integers use a two's complement representation, this
2287instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2288
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2289<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2290<pre>
2291 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2292 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2293</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2294</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2296<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2297<div class="doc_subsubsection">
2298 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2299</div>
2300
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2301<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2303<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2304<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]2305</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2306<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2307<p>The '<tt>mul</tt>' instruction returns the product of its two
2308operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2311
2312<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2313href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2314or <a href="#t_vector">vector</a> values. Both arguments must have identical
2315types.</p>
2316
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2317<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2318
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2319<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2320two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2321
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2322<p>If the result of an integer multiplication has unsigned overflow,
2323the result returned is the mathematical result modulo
23242<sup>n</sup>, where n is the bit width of the result.</p>
2325<p>Because LLVM integers use a two's complement representation, and the
2326result is the same width as the operands, this instruction returns the
2327correct result for both signed and unsigned integers. If a full product
2328(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2329should be sign-extended or zero-extended as appropriate to the
2330width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2331<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2332<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]2333</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2334</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2335
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2336<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2337<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2338</a></div>
2339<div class="doc_text">
2340<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2341<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]2342</pre>
2343<h5>Overview:</h5>
2344<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2345operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2346
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2347<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2348
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2349<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2350<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2351values. Both arguments must have identical types.</p>
2352
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2353<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2354
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2355<p>The value produced is the unsigned integer quotient of the two operands.</p>
2356<p>Note that unsigned integer division and signed integer division are distinct
2357operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2358<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2359<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2360<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]2361</pre>
2362</div>
2363<!-- _______________________________________________________________________ -->
2364<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2365</a> </div>
2366<div class="doc_text">
2367<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2368<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2369 &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]2370</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2371
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2372<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2373
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2374<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2375operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2376
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2377<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2378
2379<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2380<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2381values. Both arguments must have identical types.</p>
2382
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2383<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2384<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]2385<p>Note that signed integer division and unsigned integer division are distinct
2386operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2387<p>Division by zero leads to undefined behavior. Overflow also leads to
2388undefined behavior; this is a rare case, but can occur, for example,
2389by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2390<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2391<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]2392</pre>
2393</div>
2394<!-- _______________________________________________________________________ -->
2395<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2396Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2397<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2398<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2399<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2400 &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]2401</pre>
2402<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2403
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2404<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2405operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2406
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2407<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2408
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2409<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2410<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2411of floating point values. Both arguments must have identical types.</p>
2412
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2413<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2414
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2415<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2416
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2417<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2418
2419<pre>
2420 &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]2421</pre>
2422</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2423
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2424<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2425<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2426</div>
2427<div class="doc_text">
2428<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2429<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]2430</pre>
2431<h5>Overview:</h5>
2432<p>The '<tt>urem</tt>' instruction returns the remainder from the
2433unsigned division of its two arguments.</p>
2434<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2435<p>The two arguments to the '<tt>urem</tt>' instruction must be
2436<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2437values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2438<h5>Semantics:</h5>
2439<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2440This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2441<p>Note that unsigned integer remainder and signed integer remainder are
2442distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2443<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2444<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2445<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]2446</pre>
2447
2448</div>
2449<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2450<div class="doc_subsubsection">
2451 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2452</div>
2453
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2454<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2455
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2456<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2457
2458<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2459 &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]2460</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2461
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2462<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2463
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2464<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2465signed division of its two operands. This instruction can also take
2466<a href="#t_vector">vector</a> versions of the values in which case
2467the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2468
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2469<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2470
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2471<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2472<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2473values. Both arguments must have identical types.</p>
2474
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2475<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2476
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2477<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2478has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2479operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2480a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2481 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2482Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2483please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2484Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2485<p>Note that signed integer remainder and unsigned integer remainder are
2486distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2487<p>Taking the remainder of a division by zero leads to undefined behavior.
2488Overflow also leads to undefined behavior; this is a rare case, but can occur,
2489for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2490(The remainder doesn't actually overflow, but this rule lets srem be
2491implemented using instructions that return both the result of the division
2492and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2493<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2494<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]2495</pre>
2496
2497</div>
2498<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2499<div class="doc_subsubsection">
2500 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2501
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2502<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2503
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2504<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2505<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]2506</pre>
2507<h5>Overview:</h5>
2508<p>The '<tt>frem</tt>' instruction returns the remainder from the
2509division of its two operands.</p>
2510<h5>Arguments:</h5>
2511<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2512<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2513of floating point values. Both arguments must have identical types.</p>
2514
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2515<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2516
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2517<p>This instruction returns the <i>remainder</i> of a division.
2518The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2519
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2520<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2521
2522<pre>
2523 &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]2524</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2525</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2526
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2527<!-- ======================================================================= -->
2528<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2529Operations</a> </div>
2530<div class="doc_text">
2531<p>Bitwise binary operators are used to do various forms of
2532bit-twiddling in a program. They are generally very efficient
2533instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2534instructions. They require two operands of the same type, execute an operation on them,
2535and 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]2536</div>
2537
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2538<!-- _______________________________________________________________________ -->
2539<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2540Instruction</a> </div>
2541<div class="doc_text">
2542<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2543<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]2544</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2545
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2546<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2547
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2548<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2549the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2550
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2551<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2552
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2553<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2554 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2555type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2556
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2557<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2558
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2559<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2560where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2561equal 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]2562
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2563<h5>Example:</h5><pre>
2564 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2565 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2566 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2567 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2568</pre>
2569</div>
2570<!-- _______________________________________________________________________ -->
2571<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2572Instruction</a> </div>
2573<div class="doc_text">
2574<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2575<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]2576</pre>
2577
2578<h5>Overview:</h5>
2579<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2580operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2581
2582<h5>Arguments:</h5>
2583<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2584<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]2585type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2586
2587<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2588
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2589<p>This instruction always performs a logical shift right operation. The most
2590significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2591shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2592the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2593
2594<h5>Example:</h5>
2595<pre>
2596 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2597 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2598 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2599 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2600 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2601</pre>
2602</div>
2603
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2604<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2605<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2606Instruction</a> </div>
2607<div class="doc_text">
2608
2609<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2610<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]2611</pre>
2612
2613<h5>Overview:</h5>
2614<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2615operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2616
2617<h5>Arguments:</h5>
2618<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2619<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]2620type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2621
2622<h5>Semantics:</h5>
2623<p>This instruction always performs an arithmetic shift right operation,
2624The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2625of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2626larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2627</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2628
2629<h5>Example:</h5>
2630<pre>
2631 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2632 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2633 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2634 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2635 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2636</pre>
2637</div>
2638
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2639<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2640<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2641Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2642
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2643<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2644
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2645<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2646
2647<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2648 &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]2649</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2650
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2651<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2652
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2653<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2654its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2655
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2656<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2657
2658<p>The two arguments to the '<tt>and</tt>' instruction must be
2659<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2660values. Both arguments must have identical types.</p>
2661
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2662<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2663<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2664<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2665<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2666<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2667 <tbody>
2668 <tr>
2669 <td>In0</td>
2670 <td>In1</td>
2671 <td>Out</td>
2672 </tr>
2673 <tr>
2674 <td>0</td>
2675 <td>0</td>
2676 <td>0</td>
2677 </tr>
2678 <tr>
2679 <td>0</td>
2680 <td>1</td>
2681 <td>0</td>
2682 </tr>
2683 <tr>
2684 <td>1</td>
2685 <td>0</td>
2686 <td>0</td>
2687 </tr>
2688 <tr>
2689 <td>1</td>
2690 <td>1</td>
2691 <td>1</td>
2692 </tr>
2693 </tbody>
2694</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2695</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2696<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2697<pre>
2698 &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]2699 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2700 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2701</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2702</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2703<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2704<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2705<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2706<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2707<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]2708</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2709<h5>Overview:</h5>
2710<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2711or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2712<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2713
2714<p>The two arguments to the '<tt>or</tt>' instruction must be
2715<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2716values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2717<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2718<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2719<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2720<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2721<table border="1" cellspacing="0" cellpadding="4">
2722 <tbody>
2723 <tr>
2724 <td>In0</td>
2725 <td>In1</td>
2726 <td>Out</td>
2727 </tr>
2728 <tr>
2729 <td>0</td>
2730 <td>0</td>
2731 <td>0</td>
2732 </tr>
2733 <tr>
2734 <td>0</td>
2735 <td>1</td>
2736 <td>1</td>
2737 </tr>
2738 <tr>
2739 <td>1</td>
2740 <td>0</td>
2741 <td>1</td>
2742 </tr>
2743 <tr>
2744 <td>1</td>
2745 <td>1</td>
2746 <td>1</td>
2747 </tr>
2748 </tbody>
2749</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2750</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2751<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2752<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2753 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2754 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2755</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2756</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2757<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2758<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2759Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2760<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2761<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2762<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]2763</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2764<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2765<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2766or of its two operands. The <tt>xor</tt> is used to implement the
2767"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2768<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2769<p>The two arguments to the '<tt>xor</tt>' instruction must be
2770<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2771values. Both arguments must have identical types.</p>
2772
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2774
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2775<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2776<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2777<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2778<table border="1" cellspacing="0" cellpadding="4">
2779 <tbody>
2780 <tr>
2781 <td>In0</td>
2782 <td>In1</td>
2783 <td>Out</td>
2784 </tr>
2785 <tr>
2786 <td>0</td>
2787 <td>0</td>
2788 <td>0</td>
2789 </tr>
2790 <tr>
2791 <td>0</td>
2792 <td>1</td>
2793 <td>1</td>
2794 </tr>
2795 <tr>
2796 <td>1</td>
2797 <td>0</td>
2798 <td>1</td>
2799 </tr>
2800 <tr>
2801 <td>1</td>
2802 <td>1</td>
2803 <td>0</td>
2804 </tr>
2805 </tbody>
2806</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2807</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2808<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2809<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2810<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2811 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2812 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2813 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2814</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2815</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2816
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2817<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2818<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2819 <a name="vectorops">Vector Operations</a>
2820</div>
2821
2822<div class="doc_text">
2823
2824<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2825target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2826vector-specific operations needed to process vectors effectively. While LLVM
2827does directly support these vector operations, many sophisticated algorithms
2828will want to use target-specific intrinsics to take full advantage of a specific
2829target.</p>
2830
2831</div>
2832
2833<!-- _______________________________________________________________________ -->
2834<div class="doc_subsubsection">
2835 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2836</div>
2837
2838<div class="doc_text">
2839
2840<h5>Syntax:</h5>
2841
2842<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2843 &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]2844</pre>
2845
2846<h5>Overview:</h5>
2847
2848<p>
2849The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2850element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2851</p>
2852
2853
2854<h5>Arguments:</h5>
2855
2856<p>
2857The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2858value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2859an index indicating the position from which to extract the element.
2860The index may be a variable.</p>
2861
2862<h5>Semantics:</h5>
2863
2864<p>
2865The result is a scalar of the same type as the element type of
2866<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2867<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2868results are undefined.
2869</p>
2870
2871<h5>Example:</h5>
2872
2873<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2874 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2875</pre>
2876</div>
2877
2878
2879<!-- _______________________________________________________________________ -->
2880<div class="doc_subsubsection">
2881 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2882</div>
2883
2884<div class="doc_text">
2885
2886<h5>Syntax:</h5>
2887
2888<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2889 &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]2890</pre>
2891
2892<h5>Overview:</h5>
2893
2894<p>
2895The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2896element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2897</p>
2898
2899
2900<h5>Arguments:</h5>
2901
2902<p>
2903The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2904value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2905scalar value whose type must equal the element type of the first
2906operand. The third operand is an index indicating the position at
2907which to insert the value. The index may be a variable.</p>
2908
2909<h5>Semantics:</h5>
2910
2911<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2912The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2913element values are those of <tt>val</tt> except at position
2914<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2915exceeds the length of <tt>val</tt>, the results are undefined.
2916</p>
2917
2918<h5>Example:</h5>
2919
2920<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2921 %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]2922</pre>
2923</div>
2924
2925<!-- _______________________________________________________________________ -->
2926<div class="doc_subsubsection">
2927 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2928</div>
2929
2930<div class="doc_text">
2931
2932<h5>Syntax:</h5>
2933
2934<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2935 &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]2936</pre>
2937
2938<h5>Overview:</h5>
2939
2940<p>
2941The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2942from two input vectors, returning a vector of the same type.
2943</p>
2944
2945<h5>Arguments:</h5>
2946
2947<p>
2948The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2949with types that match each other and types that match the result of the
2950instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2951of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2952</p>
2953
2954<p>
2955The shuffle mask operand is required to be a constant vector with either
2956constant integer or undef values.
2957</p>
2958
2959<h5>Semantics:</h5>
2960
2961<p>
2962The elements of the two input vectors are numbered from left to right across
2963both of the vectors. The shuffle mask operand specifies, for each element of
2964the result vector, which element of the two input registers the result element
2965gets. The element selector may be undef (meaning "don't care") and the second
2966operand may be undef if performing a shuffle from only one vector.
2967</p>
2968
2969<h5>Example:</h5>
2970
2971<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2972 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2973 &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]2974 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2975 &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]2976</pre>
2977</div>
2978
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2979
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2980<!-- ======================================================================= -->
2981<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2982 <a name="aggregateops">Aggregate Operations</a>
2983</div>
2984
2985<div class="doc_text">
2986
2987<p>LLVM supports several instructions for working with aggregate values.
2988</p>
2989
2990</div>
2991
2992<!-- _______________________________________________________________________ -->
2993<div class="doc_subsubsection">
2994 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
2995</div>
2996
2997<div class="doc_text">
2998
2999<h5>Syntax:</h5>
3000
3001<pre>
3002 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3003</pre>
3004
3005<h5>Overview:</h5>
3006
3007<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3008The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3009or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3010</p>
3011
3012
3013<h5>Arguments:</h5>
3014
3015<p>
3016The first operand of an '<tt>extractvalue</tt>' instruction is a
3017value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3018type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3019in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3020'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3021</p>
3022
3023<h5>Semantics:</h5>
3024
3025<p>
3026The result is the value at the position in the aggregate specified by
3027the index operands.
3028</p>
3029
3030<h5>Example:</h5>
3031
3032<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3033 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3034</pre>
3035</div>
3036
3037
3038<!-- _______________________________________________________________________ -->
3039<div class="doc_subsubsection">
3040 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3041</div>
3042
3043<div class="doc_text">
3044
3045<h5>Syntax:</h5>
3046
3047<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3048 &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]3049</pre>
3050
3051<h5>Overview:</h5>
3052
3053<p>
3054The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3055into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3056</p>
3057
3058
3059<h5>Arguments:</h5>
3060
3061<p>
3062The first operand of an '<tt>insertvalue</tt>' instruction is a
3063value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3064The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3065The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3066indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3067indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3068'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3069The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3070by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3071</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3072
3073<h5>Semantics:</h5>
3074
3075<p>
3076The result is an aggregate of the same type as <tt>val</tt>. Its
3077value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3078specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3079</p>
3080
3081<h5>Example:</h5>
3082
3083<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3084 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3085</pre>
3086</div>
3087
3088
3089<!-- ======================================================================= -->
3090<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3091 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3092</div>
3093
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3094<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3095
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3096<p>A key design point of an SSA-based representation is how it
3097represents memory. In LLVM, no memory locations are in SSA form, which
3098makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3099allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3100
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3101</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3103<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3104<div class="doc_subsubsection">
3105 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3106</div>
3107
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3108<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3109
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3110<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3111
3112<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3113 &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]3114</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3115
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3116<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3117
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3118<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3119heap and returns a pointer to it. The object is always allocated in the generic
3120address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3121
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3122<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3123
3124<p>The '<tt>malloc</tt>' instruction allocates
3125<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3126bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3127appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3128number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3129If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3130be aligned to at least that boundary. If not specified, or if zero, the target can
3131choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3132
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3133<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3134
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3135<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3136
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3137<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3138a pointer is returned. The result of a zero byte allocattion is undefined. The
3139result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3140
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3141<h5>Example:</h5>
3142
3143<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3144 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3145
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3146 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3147 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3148 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3149 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3150 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3151</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3152</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3153
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3154<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3155<div class="doc_subsubsection">
3156 <a name="i_free">'<tt>free</tt>' Instruction</a>
3157</div>
3158
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3159<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3160
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3161<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3162
3163<pre>
3164 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3165</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3166
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3167<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3168
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3169<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3170memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3171
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3172<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3173
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3174<p>'<tt>value</tt>' shall be a pointer value that points to a value
3175that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3176instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3177
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3178<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3179
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3180<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3181after this instruction executes. If the pointer is null, the operation
3182is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3183
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3184<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3185
3186<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3187 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3188 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3189</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3190</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3191
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3192<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3193<div class="doc_subsubsection">
3194 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3195</div>
3196
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3197<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3198
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3199<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3200
3201<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3202 &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]3203</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3204
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3205<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3206
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3207<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3208currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3209returns to its caller. The object is always allocated in the generic address
3210space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3211
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3212<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3213
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3214<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3215bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3216appropriate type to the program. If "NumElements" is specified, it is the
3217number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3218If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3219to be aligned to at least that boundary. If not specified, or if zero, the target
3220can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3221
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3222<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3223
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3224<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3225
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3226<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3227there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3228memory is automatically released when the function returns. The '<tt>alloca</tt>'
3229instruction is commonly used to represent automatic variables that must
3230have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3231 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]3232instructions), the memory is reclaimed. Allocating zero bytes
3233is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3234
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3235<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3236
3237<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3238 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3239 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3240 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3241 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3242</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3243</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3244
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3245<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3246<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3247Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3248<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3249<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3250<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]3251<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3252<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3253<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3254<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3255address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3256 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3257marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3258the number or order of execution of this <tt>load</tt> with other
3259volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3260instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3261<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3262The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3263(that is, the alignment of the memory address). A value of 0 or an
3264omitted "align" argument means that the operation has the preferential
3265alignment for the target. It is the responsibility of the code emitter
3266to ensure that the alignment information is correct. Overestimating
3267the alignment results in an undefined behavior. Underestimating the
3268alignment may produce less efficient code. An alignment of 1 is always
3269safe.
3270</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3271<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3272<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3273<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3274<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3275 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3276 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3277 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3278</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3279</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3280<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3281<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3282Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3283<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3284<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3285<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3286 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]3287</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3288<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3289<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3290<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3291<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3292to 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]3293operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3294of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3295operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3296optimizer is not allowed to modify the number or order of execution of
3297this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3298 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3299<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3300The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3301(that is, the alignment of the memory address). A value of 0 or an
3302omitted "align" argument means that the operation has the preferential
3303alignment for the target. It is the responsibility of the code emitter
3304to ensure that the alignment information is correct. Overestimating
3305the alignment results in an undefined behavior. Underestimating the
3306alignment may produce less efficient code. An alignment of 1 is always
3307safe.
3308</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3309<h5>Semantics:</h5>
3310<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3311at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3312<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3313<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3314 store i32 3, i32* %ptr <i>; yields {void}</i>
3315 %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]3316</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3317</div>
3318
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3319<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3320<div class="doc_subsubsection">
3321 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3322</div>
3323
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3324<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3325<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3326<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3327 &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]3328</pre>
3329
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3330<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3331
3332<p>
3333The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3334subelement of an aggregate data structure. It performs address calculation only
3335and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3336
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3337<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3338
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3339<p>The first argument is always a pointer, and forms the basis of the
3340calculation. The remaining arguments are indices, that indicate which of the
3341elements of the aggregate object are indexed. The interpretation of each index
3342is dependent on the type being indexed into. The first index always indexes the
3343pointer value given as the first argument, the second index indexes a value of
3344the type pointed to (not necessarily the value directly pointed to, since the
3345first index can be non-zero), etc. The first type indexed into must be a pointer
3346value, subsequent types can be arrays, vectors and structs. Note that subsequent
3347types being indexed into can never be pointers, since that would require loading
3348the pointer before continuing calculation.</p>
3349
3350<p>The type of each index argument depends on the type it is indexing into.
3351When indexing into a (packed) structure, only <tt>i32</tt> integer
3352<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3353only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3354will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3355
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3356<p>For example, let's consider a C code fragment and how it gets
3357compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3358
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3359<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3360<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3361struct RT {
3362 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3363 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3364 char C;
3365};
3366struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3367 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3368 double Y;
3369 struct RT Z;
3370};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3371
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3372int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3373 return &amp;s[1].Z.B[5][13];
3374}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3375</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3376</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3377
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3378<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3379
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3380<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3381<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3382%RT = type { i8 , [10 x [20 x i32]], i8 }
3383%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3384
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3385define i32* %foo(%ST* %s) {
3386entry:
3387 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3388 ret i32* %reg
3389}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3390</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3391</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3392
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3393<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3394
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3395<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]3396type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3397}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3398the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3399i8 }</tt>' type, another structure. The third index indexes into the second
3400element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3401array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3402'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3403to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3404
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3405<p>Note that it is perfectly legal to index partially through a
3406structure, returning a pointer to an inner element. Because of this,
3407the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3408
3409<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3410 define i32* %foo(%ST* %s) {
3411 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3412 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3413 %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]3414 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3415 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3416 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3417 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3418</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3419
3420<p>Note that it is undefined to access an array out of bounds: array and
3421pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3422The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3423defined to be accessible as variable length arrays, which requires access
3424beyond the zero'th element.</p>
3425
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3426<p>The getelementptr instruction is often confusing. For some more insight
3427into how it works, see <a href="GetElementPtr.html">the getelementptr
3428FAQ</a>.</p>
3429
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3430<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3431
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3432<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3433 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3434 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3435 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3436 %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]3437 <i>; yields i8*:eptr</i>
3438 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3439</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3440</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3441
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3442<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3443<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3444</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3445<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3446<p>The instructions in this category are the conversion instructions (casting)
3447which all take a single operand and a type. They perform various bit conversions
3448on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3449</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3450
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3451<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3452<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3453 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3454</div>
3455<div class="doc_text">
3456
3457<h5>Syntax:</h5>
3458<pre>
3459 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3460</pre>
3461
3462<h5>Overview:</h5>
3463<p>
3464The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3465</p>
3466
3467<h5>Arguments:</h5>
3468<p>
3469The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3470be 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]3471and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3472type. The bit size of <tt>value</tt> must be larger than the bit size of
3473<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3474
3475<h5>Semantics:</h5>
3476<p>
3477The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3478and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3479larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3480It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3481
3482<h5>Example:</h5>
3483<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3484 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3485 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3486 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3487</pre>
3488</div>
3489
3490<!-- _______________________________________________________________________ -->
3491<div class="doc_subsubsection">
3492 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3493</div>
3494<div class="doc_text">
3495
3496<h5>Syntax:</h5>
3497<pre>
3498 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3499</pre>
3500
3501<h5>Overview:</h5>
3502<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3503<tt>ty2</tt>.</p>
3504
3505
3506<h5>Arguments:</h5>
3507<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]3508<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3509also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3510<tt>value</tt> must be smaller than the bit size of the destination type,
3511<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3512
3513<h5>Semantics:</h5>
3514<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]3515bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3516
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3517<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]3518
3519<h5>Example:</h5>
3520<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3521 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3522 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3523</pre>
3524</div>
3525
3526<!-- _______________________________________________________________________ -->
3527<div class="doc_subsubsection">
3528 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3529</div>
3530<div class="doc_text">
3531
3532<h5>Syntax:</h5>
3533<pre>
3534 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3535</pre>
3536
3537<h5>Overview:</h5>
3538<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3539
3540<h5>Arguments:</h5>
3541<p>
3542The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3543<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3544also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3545<tt>value</tt> must be smaller than the bit size of the destination type,
3546<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3547
3548<h5>Semantics:</h5>
3549<p>
3550The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3551bit (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]3552the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3553
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3554<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]3555
3556<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3557<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3558 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3559 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3560</pre>
3561</div>
3562
3563<!-- _______________________________________________________________________ -->
3564<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3565 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3566</div>
3567
3568<div class="doc_text">
3569
3570<h5>Syntax:</h5>
3571
3572<pre>
3573 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3574</pre>
3575
3576<h5>Overview:</h5>
3577<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3578<tt>ty2</tt>.</p>
3579
3580
3581<h5>Arguments:</h5>
3582<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3583 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3584cast it to. The size of <tt>value</tt> must be larger than the size of
3585<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3586<i>no-op cast</i>.</p>
3587
3588<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3589<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3590<a href="#t_floating">floating point</a> type to a smaller
3591<a href="#t_floating">floating point</a> type. If the value cannot fit within
3592the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3593
3594<h5>Example:</h5>
3595<pre>
3596 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3597 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3598</pre>
3599</div>
3600
3601<!-- _______________________________________________________________________ -->
3602<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3603 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3604</div>
3605<div class="doc_text">
3606
3607<h5>Syntax:</h5>
3608<pre>
3609 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3610</pre>
3611
3612<h5>Overview:</h5>
3613<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3614floating point value.</p>
3615
3616<h5>Arguments:</h5>
3617<p>The '<tt>fpext</tt>' instruction takes a
3618<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3619and a <a href="#t_floating">floating point</a> type to cast it to. The source
3620type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3621
3622<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3623<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3624<a href="#t_floating">floating point</a> type to a larger
3625<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3626used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3627<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]3628
3629<h5>Example:</h5>
3630<pre>
3631 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3632 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3633</pre>
3634</div>
3635
3636<!-- _______________________________________________________________________ -->
3637<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3638 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3639</div>
3640<div class="doc_text">
3641
3642<h5>Syntax:</h5>
3643<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3644 &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]3645</pre>
3646
3647<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3648<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3649unsigned integer equivalent of type <tt>ty2</tt>.
3650</p>
3651
3652<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3653<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]3654scalar or vector <a href="#t_floating">floating point</a> value, and a type
3655to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3656type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3657vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3658
3659<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3660<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3661<a href="#t_floating">floating point</a> operand into the nearest (rounding
3662towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3663the results are undefined.</p>
3664
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3665<h5>Example:</h5>
3666<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3667 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3668 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3669 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3670</pre>
3671</div>
3672
3673<!-- _______________________________________________________________________ -->
3674<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3675 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3676</div>
3677<div class="doc_text">
3678
3679<h5>Syntax:</h5>
3680<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3681 &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]3682</pre>
3683
3684<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3685<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3686<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]3687</p>
3688
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3689<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3690<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]3691scalar or vector <a href="#t_floating">floating point</a> value, and a type
3692to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3693type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3694vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3695
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3696<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3697<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3698<a href="#t_floating">floating point</a> operand into the nearest (rounding
3699towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3700the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3701
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3702<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3703<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3704 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3705 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3706 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3707</pre>
3708</div>
3709
3710<!-- _______________________________________________________________________ -->
3711<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3712 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3713</div>
3714<div class="doc_text">
3715
3716<h5>Syntax:</h5>
3717<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3718 &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]3719</pre>
3720
3721<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3722<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3723integer and converts that value to the <tt>ty2</tt> type.</p>
3724
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3725<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3726<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3727scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3728to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3729type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3730floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3731
3732<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3733<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3734integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3735the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3736
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3737<h5>Example:</h5>
3738<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3739 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3740 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3741</pre>
3742</div>
3743
3744<!-- _______________________________________________________________________ -->
3745<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3746 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3747</div>
3748<div class="doc_text">
3749
3750<h5>Syntax:</h5>
3751<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3752 &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]3753</pre>
3754
3755<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3756<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3757integer and converts that value to the <tt>ty2</tt> type.</p>
3758
3759<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3760<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3761scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3762to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3763type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3764floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3765
3766<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3767<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3768integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3769the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3770
3771<h5>Example:</h5>
3772<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3773 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3774 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3775</pre>
3776</div>
3777
3778<!-- _______________________________________________________________________ -->
3779<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3780 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3781</div>
3782<div class="doc_text">
3783
3784<h5>Syntax:</h5>
3785<pre>
3786 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3787</pre>
3788
3789<h5>Overview:</h5>
3790<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3791the integer type <tt>ty2</tt>.</p>
3792
3793<h5>Arguments:</h5>
3794<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3795must 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]3796<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]3797
3798<h5>Semantics:</h5>
3799<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3800<tt>ty2</tt> by interpreting the pointer value as an integer and either
3801truncating or zero extending that value to the size of the integer type. If
3802<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3803<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]3804are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3805change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3806
3807<h5>Example:</h5>
3808<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3809 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3810 %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]3811</pre>
3812</div>
3813
3814<!-- _______________________________________________________________________ -->
3815<div class="doc_subsubsection">
3816 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3817</div>
3818<div class="doc_text">
3819
3820<h5>Syntax:</h5>
3821<pre>
3822 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3823</pre>
3824
3825<h5>Overview:</h5>
3826<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3827a pointer type, <tt>ty2</tt>.</p>
3828
3829<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3830<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3831value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3832<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3833
3834<h5>Semantics:</h5>
3835<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3836<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3837the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3838size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3839the size of a pointer then a zero extension is done. If they are the same size,
3840nothing is done (<i>no-op cast</i>).</p>
3841
3842<h5>Example:</h5>
3843<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3844 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3845 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3846 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3847</pre>
3848</div>
3849
3850<!-- _______________________________________________________________________ -->
3851<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3852 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3853</div>
3854<div class="doc_text">
3855
3856<h5>Syntax:</h5>
3857<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3858 &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]3859</pre>
3860
3861<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3862
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3863<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3864<tt>ty2</tt> without changing any bits.</p>
3865
3866<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3867
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3868<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]3869a non-aggregate first class value, and a type to cast it to, which must also be
3870a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3871<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3872and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3873type is a pointer, the destination type must also be a pointer. This
3874instruction supports bitwise conversion of vectors to integers and to vectors
3875of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3876
3877<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3878<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3879<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3880this conversion. The conversion is done as if the <tt>value</tt> had been
3881stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3882converted to other pointer types with this instruction. To convert pointers to
3883other types, use the <a href="#i_inttoptr">inttoptr</a> or
3884<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3885
3886<h5>Example:</h5>
3887<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3888 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3889 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3890 %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]3891</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3892</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3893
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3894<!-- ======================================================================= -->
3895<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3896<div class="doc_text">
3897<p>The instructions in this category are the "miscellaneous"
3898instructions, which defy better classification.</p>
3899</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3900
3901<!-- _______________________________________________________________________ -->
3902<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3903</div>
3904<div class="doc_text">
3905<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3906<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]3907</pre>
3908<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3909<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3910a vector of boolean values based on comparison
3911of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3912<h5>Arguments:</h5>
3913<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3914the condition code indicating the kind of comparison to perform. It is not
3915a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3916</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3917<ol>
3918 <li><tt>eq</tt>: equal</li>
3919 <li><tt>ne</tt>: not equal </li>
3920 <li><tt>ugt</tt>: unsigned greater than</li>
3921 <li><tt>uge</tt>: unsigned greater or equal</li>
3922 <li><tt>ult</tt>: unsigned less than</li>
3923 <li><tt>ule</tt>: unsigned less or equal</li>
3924 <li><tt>sgt</tt>: signed greater than</li>
3925 <li><tt>sge</tt>: signed greater or equal</li>
3926 <li><tt>slt</tt>: signed less than</li>
3927 <li><tt>sle</tt>: signed less or equal</li>
3928</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3929<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3930<a href="#t_pointer">pointer</a>
3931or integer <a href="#t_vector">vector</a> typed.
3932They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3933<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3934<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]3935the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3936yields 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]3937</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3938<ol>
3939 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3940 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3941 </li>
3942 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3943 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3944 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3945 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3946 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3947 <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]3948 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3949 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3950 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3951 <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]3952 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3953 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3954 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3955 <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]3956 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3957 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3958 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3959 <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]3960</ol>
3961<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3962values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3963<p>If the operands are integer vectors, then they are compared
3964element by element. The result is an <tt>i1</tt> vector with
3965the same number of elements as the values being compared.
3966Otherwise, the result is an <tt>i1</tt>.
3967</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3968
3969<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3970<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3971 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3972 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3973 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3974 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3975 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3976</pre>
3977</div>
3978
3979<!-- _______________________________________________________________________ -->
3980<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3981</div>
3982<div class="doc_text">
3983<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3984<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]3985</pre>
3986<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3987<p>The '<tt>fcmp</tt>' instruction returns a boolean value
3988or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3989of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3990<p>
3991If the operands are floating point scalars, then the result
3992type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
3993</p>
3994<p>If the operands are floating point vectors, then the result type
3995is a vector of boolean with the same number of elements as the
3996operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3997<h5>Arguments:</h5>
3998<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3999the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4000a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4001<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4002 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4003 <li><tt>oeq</tt>: ordered and equal</li>
4004 <li><tt>ogt</tt>: ordered and greater than </li>
4005 <li><tt>oge</tt>: ordered and greater than or equal</li>
4006 <li><tt>olt</tt>: ordered and less than </li>
4007 <li><tt>ole</tt>: ordered and less than or equal</li>
4008 <li><tt>one</tt>: ordered and not equal</li>
4009 <li><tt>ord</tt>: ordered (no nans)</li>
4010 <li><tt>ueq</tt>: unordered or equal</li>
4011 <li><tt>ugt</tt>: unordered or greater than </li>
4012 <li><tt>uge</tt>: unordered or greater than or equal</li>
4013 <li><tt>ult</tt>: unordered or less than </li>
4014 <li><tt>ule</tt>: unordered or less than or equal</li>
4015 <li><tt>une</tt>: unordered or not equal</li>
4016 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4017 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4018</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4019<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4020<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4021<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4022either a <a href="#t_floating">floating point</a> type
4023or a <a href="#t_vector">vector</a> of floating point type.
4024They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4025<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4026<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4027according to the condition code given as <tt>cond</tt>.
4028If the operands are vectors, then the vectors are compared
4029element by element.
4030Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4031always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4032<ol>
4033 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4034 <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]4035 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4036 <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]4037 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4038 <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]4039 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4040 <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]4041 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4042 <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]4043 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4044 <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]4045 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4046 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4047 <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]4048 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4049 <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]4050 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4051 <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]4052 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4053 <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]4054 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4055 <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]4056 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4057 <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]4058 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4059 <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]4060 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4061</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4062
4063<h5>Example:</h5>
4064<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]4065 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4066 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4067 &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]4068</pre>
4069</div>
4070
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4071<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4072<div class="doc_subsubsection">
4073 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4074</div>
4075<div class="doc_text">
4076<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4077<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]4078</pre>
4079<h5>Overview:</h5>
4080<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4081element-wise comparison of its two integer vector operands.</p>
4082<h5>Arguments:</h5>
4083<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4084the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4085a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4086<ol>
4087 <li><tt>eq</tt>: equal</li>
4088 <li><tt>ne</tt>: not equal </li>
4089 <li><tt>ugt</tt>: unsigned greater than</li>
4090 <li><tt>uge</tt>: unsigned greater or equal</li>
4091 <li><tt>ult</tt>: unsigned less than</li>
4092 <li><tt>ule</tt>: unsigned less or equal</li>
4093 <li><tt>sgt</tt>: signed greater than</li>
4094 <li><tt>sge</tt>: signed greater or equal</li>
4095 <li><tt>slt</tt>: signed less than</li>
4096 <li><tt>sle</tt>: signed less or equal</li>
4097</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4098<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4099<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4100<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4101<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4102according to the condition code given as <tt>cond</tt>. The comparison yields a
4103<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4104identical type as the values being compared. The most significant bit in each
4105element is 1 if the element-wise comparison evaluates to true, and is 0
4106otherwise. All other bits of the result are undefined. The condition codes
4107are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4108instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4109
4110<h5>Example:</h5>
4111<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4112 &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>
4113 &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]4114</pre>
4115</div>
4116
4117<!-- _______________________________________________________________________ -->
4118<div class="doc_subsubsection">
4119 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4120</div>
4121<div class="doc_text">
4122<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4123<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]4124<h5>Overview:</h5>
4125<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4126element-wise comparison of its two floating point vector operands. The output
4127elements have the same width as the input elements.</p>
4128<h5>Arguments:</h5>
4129<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4130the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4131a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4132<ol>
4133 <li><tt>false</tt>: no comparison, always returns false</li>
4134 <li><tt>oeq</tt>: ordered and equal</li>
4135 <li><tt>ogt</tt>: ordered and greater than </li>
4136 <li><tt>oge</tt>: ordered and greater than or equal</li>
4137 <li><tt>olt</tt>: ordered and less than </li>
4138 <li><tt>ole</tt>: ordered and less than or equal</li>
4139 <li><tt>one</tt>: ordered and not equal</li>
4140 <li><tt>ord</tt>: ordered (no nans)</li>
4141 <li><tt>ueq</tt>: unordered or equal</li>
4142 <li><tt>ugt</tt>: unordered or greater than </li>
4143 <li><tt>uge</tt>: unordered or greater than or equal</li>
4144 <li><tt>ult</tt>: unordered or less than </li>
4145 <li><tt>ule</tt>: unordered or less than or equal</li>
4146 <li><tt>une</tt>: unordered or not equal</li>
4147 <li><tt>uno</tt>: unordered (either nans)</li>
4148 <li><tt>true</tt>: no comparison, always returns true</li>
4149</ol>
4150<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4151<a href="#t_floating">floating point</a> typed. They must also be identical
4152types.</p>
4153<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4154<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4155according to the condition code given as <tt>cond</tt>. The comparison yields a
4156<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4157an identical number of elements as the values being compared, and each element
4158having identical with to the width of the floating point elements. The most
4159significant bit in each element is 1 if the element-wise comparison evaluates to
4160true, and is 0 otherwise. All other bits of the result are undefined. The
4161condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4162<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4163
4164<h5>Example:</h5>
4165<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4166 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4167 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4168
4169 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4170 &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]4171</pre>
4172</div>
4173
4174<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4175<div class="doc_subsubsection">
4176 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4177</div>
4178
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4179<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4180
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4181<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4182
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4183<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4184<h5>Overview:</h5>
4185<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4186the SSA graph representing the function.</p>
4187<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4188
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4189<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4190field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4191as arguments, with one pair for each predecessor basic block of the
4192current block. Only values of <a href="#t_firstclass">first class</a>
4193type may be used as the value arguments to the PHI node. Only labels
4194may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4195
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4196<p>There must be no non-phi instructions between the start of a basic
4197block and the PHI instructions: i.e. PHI instructions must be first in
4198a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4199
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4200<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4201
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4202<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4203specified by the pair corresponding to the predecessor basic block that executed
4204just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4205
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4206<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4207<pre>
4208Loop: ; Infinite loop that counts from 0 on up...
4209 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4210 %nextindvar = add i32 %indvar, 1
4211 br label %Loop
4212</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4213</div>
4214
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4215<!-- _______________________________________________________________________ -->
4216<div class="doc_subsubsection">
4217 <a name="i_select">'<tt>select</tt>' Instruction</a>
4218</div>
4219
4220<div class="doc_text">
4221
4222<h5>Syntax:</h5>
4223
4224<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4225 &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>
4226
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4227 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4228</pre>
4229
4230<h5>Overview:</h5>
4231
4232<p>
4233The '<tt>select</tt>' instruction is used to choose one value based on a
4234condition, without branching.
4235</p>
4236
4237
4238<h5>Arguments:</h5>
4239
4240<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4241The '<tt>select</tt>' instruction requires an 'i1' value or
4242a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4243condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4244type. If the val1/val2 are vectors and
4245the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4246individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4247</p>
4248
4249<h5>Semantics:</h5>
4250
4251<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4252If 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]4253value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4254</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4255<p>
4256If the condition is a vector of i1, then the value arguments must
4257be vectors of the same size, and the selection is done element
4258by element.
4259</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4260
4261<h5>Example:</h5>
4262
4263<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4264 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4265</pre>
4266</div>
4267
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4268
4269<!-- _______________________________________________________________________ -->
4270<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4271 <a name="i_call">'<tt>call</tt>' Instruction</a>
4272</div>
4273
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4274<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4275
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4276<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4277<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4278 &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]4279</pre>
4280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4281<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4282
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4283<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4284
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4285<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4286
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4287<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4288
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4289<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4290 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4291 <p>The optional "tail" marker indicates whether the callee function accesses
4292 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4293 function call is eligible for tail call optimization. Note that calls may
4294 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4295 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4296 </li>
4297 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4298 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4299 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4300 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4301 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4302
4303 <li>
4304 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4305 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4306 and '<tt>inreg</tt>' attributes are valid here.</p>
4307 </li>
4308
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4309 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4310 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4311 the type of the return value. Functions that return no value are marked
4312 <tt><a href="#t_void">void</a></tt>.</p>
4313 </li>
4314 <li>
4315 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4316 value being invoked. The argument types must match the types implied by
4317 this signature. This type can be omitted if the function is not varargs
4318 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4319 </li>
4320 <li>
4321 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4322 be invoked. In most cases, this is a direct function invocation, but
4323 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4324 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4325 </li>
4326 <li>
4327 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4328 function signature argument types. All arguments must be of
4329 <a href="#t_firstclass">first class</a> type. If the function signature
4330 indicates the function accepts a variable number of arguments, the extra
4331 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4332 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4333 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4334 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4335 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4336 '<tt>readnone</tt>' attributes are valid here.</p>
4337 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4338</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4339
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4340<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4341
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4342<p>The '<tt>call</tt>' instruction is used to cause control flow to
4343transfer to a specified function, with its incoming arguments bound to
4344the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4345instruction in the called function, control flow continues with the
4346instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4347function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4348
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4349<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4350
4351<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4352 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4353 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4354 %X = tail call i32 @foo() <i>; yields i32</i>
4355 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4356 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4357
4358 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4359 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4360 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4361 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4362 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4363 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4364</pre>
4365
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4366</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4367
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4368<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4369<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4370 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4371</div>
4372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4373<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4374
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4375<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4376
4377<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4378 &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]4379</pre>
4380
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4381<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4382
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4383<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4384the "variable argument" area of a function call. It is used to implement the
4385<tt>va_arg</tt> macro in C.</p>
4386
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4387<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4388
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4389<p>This instruction takes a <tt>va_list*</tt> value and the type of
4390the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4391increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4392actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4393
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4394<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4395
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4396<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4397type from the specified <tt>va_list</tt> and causes the
4398<tt>va_list</tt> to point to the next argument. For more information,
4399see the variable argument handling <a href="#int_varargs">Intrinsic
4400Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4401
4402<p>It is legal for this instruction to be called in a function which does not
4403take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4404function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4405
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4406<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4407href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4408argument.</p>
4409
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4410<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4411
4412<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4413
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4414</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4415
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4416<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4417<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4418<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4419
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4420<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4421
4422<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4423well known names and semantics and are required to follow certain restrictions.
4424Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4425language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4426adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4427
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4428<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4429prefix is reserved in LLVM for intrinsic names; thus, function names may not
4430begin with this prefix. Intrinsic functions must always be external functions:
4431you cannot define the body of intrinsic functions. Intrinsic functions may
4432only be used in call or invoke instructions: it is illegal to take the address
4433of an intrinsic function. Additionally, because intrinsic functions are part
4434of the LLVM language, it is required if any are added that they be documented
4435here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4436
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4437<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4438a family of functions that perform the same operation but on different data
4439types. Because LLVM can represent over 8 million different integer types,
4440overloading is used commonly to allow an intrinsic function to operate on any
4441integer type. One or more of the argument types or the result type can be
4442overloaded to accept any integer type. Argument types may also be defined as
4443exactly matching a previous argument's type or the result type. This allows an
4444intrinsic function which accepts multiple arguments, but needs all of them to
4445be of the same type, to only be overloaded with respect to a single argument or
4446the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4447
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4448<p>Overloaded intrinsics will have the names of its overloaded argument types
4449encoded into its function name, each preceded by a period. Only those types
4450which are overloaded result in a name suffix. Arguments whose type is matched
4451against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4452take an integer of any width and returns an integer of exactly the same integer
4453width. This leads to a family of functions such as
4454<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4455Only one type, the return type, is overloaded, and only one type suffix is
4456required. Because the argument's type is matched against the return type, it
4457does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4458
4459<p>To learn how to add an intrinsic function, please see the
4460<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4461</p>
4462
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4463</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4464
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4465<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4466<div class="doc_subsection">
4467 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4468</div>
4469
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4470<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4471
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4472<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4473 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4474intrinsic functions. These functions are related to the similarly
4475named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4476
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4477<p>All of these functions operate on arguments that use a
4478target-specific value type "<tt>va_list</tt>". The LLVM assembly
4479language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4480transformations should be prepared to handle these functions regardless of
4481the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4482
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4483<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]4484instruction and the variable argument handling intrinsic functions are
4485used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4486
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4487<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4488<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4489define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4490 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4491 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4492 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4493 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4494
4495 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4496 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4497
4498 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4499 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4500 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4501 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4502 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4503
4504 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4505 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4506 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4507}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4508
4509declare void @llvm.va_start(i8*)
4510declare void @llvm.va_copy(i8*, i8*)
4511declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4512</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4513</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4514
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4515</div>
4516
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4517<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4518<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4519 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4520</div>
4521
4522
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4523<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4524<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4525<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4526<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4527<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4528<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4529href="#i_va_arg">va_arg</a></tt>.</p>
4530
4531<h5>Arguments:</h5>
4532
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4533<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]4534
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4535<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4536
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4537<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]4538macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4539<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]4540<tt>va_arg</tt> will produce the first variable argument passed to the function.
4541Unlike 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]4542last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4543
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4544</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4545
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4546<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4547<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4548 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4549</div>
4550
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4551<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4552<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4553<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4554<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4555
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4556<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4557which 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]4558or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4559
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4560<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4561
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4562<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]4563
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4564<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4565
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4566<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]4567macro available in C. In a target-dependent way, it destroys the
4568<tt>va_list</tt> element to which the argument points. Calls to <a
4569href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4570<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4571<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4572
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4573</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4574
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4575<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4576<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4577 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4578</div>
4579
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4580<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4581
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4582<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4583
4584<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4585 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4586</pre>
4587
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4588<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4589
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4590<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4591from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4592
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4593<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4594
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4595<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]4596The 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]4597
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4598
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4599<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4600
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4601<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4602macro available in C. In a target-dependent way, it copies the source
4603<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4604intrinsic is necessary because the <tt><a href="#int_va_start">
4605llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4606example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4607
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4608</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4609
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4610<!-- ======================================================================= -->
4611<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4612 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4613</div>
4614
4615<div class="doc_text">
4616
4617<p>
4618LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4619Collection</a> (GC) requires the implementation and generation of these
4620intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4621These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4622stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4623href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4624Front-ends for type-safe garbage collected languages should generate these
4625intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4626href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4627</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4628
4629<p>The garbage collection intrinsics only operate on objects in the generic
4630 address space (address space zero).</p>
4631
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4632</div>
4633
4634<!-- _______________________________________________________________________ -->
4635<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4636 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4637</div>
4638
4639<div class="doc_text">
4640
4641<h5>Syntax:</h5>
4642
4643<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4644 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4645</pre>
4646
4647<h5>Overview:</h5>
4648
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4649<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]4650the code generator, and allows some metadata to be associated with it.</p>
4651
4652<h5>Arguments:</h5>
4653
4654<p>The first argument specifies the address of a stack object that contains the
4655root pointer. The second pointer (which must be either a constant or a global
4656value address) contains the meta-data to be associated with the root.</p>
4657
4658<h5>Semantics:</h5>
4659
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4660<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]4661location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4662the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4663intrinsic may only be used in a function which <a href="#gc">specifies a GC
4664algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4665
4666</div>
4667
4668
4669<!-- _______________________________________________________________________ -->
4670<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4671 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4672</div>
4673
4674<div class="doc_text">
4675
4676<h5>Syntax:</h5>
4677
4678<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4679 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4680</pre>
4681
4682<h5>Overview:</h5>
4683
4684<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4685locations, allowing garbage collector implementations that require read
4686barriers.</p>
4687
4688<h5>Arguments:</h5>
4689
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4690<p>The second argument is the address to read from, which should be an address
4691allocated from the garbage collector. The first object is a pointer to the
4692start of the referenced object, if needed by the language runtime (otherwise
4693null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4694
4695<h5>Semantics:</h5>
4696
4697<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4698instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4699garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4700may only be used in a function which <a href="#gc">specifies a GC
4701algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4702
4703</div>
4704
4705
4706<!-- _______________________________________________________________________ -->
4707<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4708 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4709</div>
4710
4711<div class="doc_text">
4712
4713<h5>Syntax:</h5>
4714
4715<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4716 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4717</pre>
4718
4719<h5>Overview:</h5>
4720
4721<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4722locations, allowing garbage collector implementations that require write
4723barriers (such as generational or reference counting collectors).</p>
4724
4725<h5>Arguments:</h5>
4726
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4727<p>The first argument is the reference to store, the second is the start of the
4728object to store it to, and the third is the address of the field of Obj to
4729store to. If the runtime does not require a pointer to the object, Obj may be
4730null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4731
4732<h5>Semantics:</h5>
4733
4734<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4735instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4736garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4737may only be used in a function which <a href="#gc">specifies a GC
4738algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4739
4740</div>
4741
4742
4743
4744<!-- ======================================================================= -->
4745<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4746 <a name="int_codegen">Code Generator Intrinsics</a>
4747</div>
4748
4749<div class="doc_text">
4750<p>
4751These intrinsics are provided by LLVM to expose special features that may only
4752be implemented with code generator support.
4753</p>
4754
4755</div>
4756
4757<!-- _______________________________________________________________________ -->
4758<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4759 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4760</div>
4761
4762<div class="doc_text">
4763
4764<h5>Syntax:</h5>
4765<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4766 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4767</pre>
4768
4769<h5>Overview:</h5>
4770
4771<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4772The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4773target-specific value indicating the return address of the current function
4774or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4775</p>
4776
4777<h5>Arguments:</h5>
4778
4779<p>
4780The argument to this intrinsic indicates which function to return the address
4781for. Zero indicates the calling function, one indicates its caller, etc. The
4782argument is <b>required</b> to be a constant integer value.
4783</p>
4784
4785<h5>Semantics:</h5>
4786
4787<p>
4788The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4789the return address of the specified call frame, or zero if it cannot be
4790identified. The value returned by this intrinsic is likely to be incorrect or 0
4791for arguments other than zero, so it should only be used for debugging purposes.
4792</p>
4793
4794<p>
4795Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4796aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4797source-language caller.
4798</p>
4799</div>
4800
4801
4802<!-- _______________________________________________________________________ -->
4803<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4804 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4805</div>
4806
4807<div class="doc_text">
4808
4809<h5>Syntax:</h5>
4810<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4811 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4812</pre>
4813
4814<h5>Overview:</h5>
4815
4816<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4817The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4818target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4819</p>
4820
4821<h5>Arguments:</h5>
4822
4823<p>
4824The argument to this intrinsic indicates which function to return the frame
4825pointer for. Zero indicates the calling function, one indicates its caller,
4826etc. The argument is <b>required</b> to be a constant integer value.
4827</p>
4828
4829<h5>Semantics:</h5>
4830
4831<p>
4832The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4833the frame address of the specified call frame, or zero if it cannot be
4834identified. The value returned by this intrinsic is likely to be incorrect or 0
4835for arguments other than zero, so it should only be used for debugging purposes.
4836</p>
4837
4838<p>
4839Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4840aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4841source-language caller.
4842</p>
4843</div>
4844
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4845<!-- _______________________________________________________________________ -->
4846<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4847 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4848</div>
4849
4850<div class="doc_text">
4851
4852<h5>Syntax:</h5>
4853<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4854 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4855</pre>
4856
4857<h5>Overview:</h5>
4858
4859<p>
4860The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4861the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4862<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4863features like scoped automatic variable sized arrays in C99.
4864</p>
4865
4866<h5>Semantics:</h5>
4867
4868<p>
4869This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4870href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4871<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4872<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4873state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4874practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4875that were allocated after the <tt>llvm.stacksave</tt> was executed.
4876</p>
4877
4878</div>
4879
4880<!-- _______________________________________________________________________ -->
4881<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4882 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4883</div>
4884
4885<div class="doc_text">
4886
4887<h5>Syntax:</h5>
4888<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4889 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4890</pre>
4891
4892<h5>Overview:</h5>
4893
4894<p>
4895The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4896the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4897href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4898useful for implementing language features like scoped automatic variable sized
4899arrays in C99.
4900</p>
4901
4902<h5>Semantics:</h5>
4903
4904<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4905See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4906</p>
4907
4908</div>
4909
4910
4911<!-- _______________________________________________________________________ -->
4912<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4913 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4914</div>
4915
4916<div class="doc_text">
4917
4918<h5>Syntax:</h5>
4919<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4920 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]4921</pre>
4922
4923<h5>Overview:</h5>
4924
4925
4926<p>
4927The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4928a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4929no
4930effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4931characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4932</p>
4933
4934<h5>Arguments:</h5>
4935
4936<p>
4937<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4938determining if the fetch should be for a read (0) or write (1), and
4939<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4940locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4941<tt>locality</tt> arguments must be constant integers.
4942</p>
4943
4944<h5>Semantics:</h5>
4945
4946<p>
4947This intrinsic does not modify the behavior of the program. In particular,
4948prefetches cannot trap and do not produce a value. On targets that support this
4949intrinsic, the prefetch can provide hints to the processor cache for better
4950performance.
4951</p>
4952
4953</div>
4954
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4955<!-- _______________________________________________________________________ -->
4956<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4957 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4958</div>
4959
4960<div class="doc_text">
4961
4962<h5>Syntax:</h5>
4963<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4964 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4965</pre>
4966
4967<h5>Overview:</h5>
4968
4969
4970<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4971The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4972(PC) in a region of
4973code to simulators and other tools. The method is target specific, but it is
4974expected that the marker will use exported symbols to transmit the PC of the
4975marker.
4976The marker makes no guarantees that it will remain with any specific instruction
4977after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4978optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4979correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4980</p>
4981
4982<h5>Arguments:</h5>
4983
4984<p>
4985<tt>id</tt> is a numerical id identifying the marker.
4986</p>
4987
4988<h5>Semantics:</h5>
4989
4990<p>
4991This intrinsic does not modify the behavior of the program. Backends that do not
4992support this intrinisic may ignore it.
4993</p>
4994
4995</div>
4996
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4997<!-- _______________________________________________________________________ -->
4998<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4999 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5000</div>
5001
5002<div class="doc_text">
5003
5004<h5>Syntax:</h5>
5005<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5006 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5007</pre>
5008
5009<h5>Overview:</h5>
5010
5011
5012<p>
5013The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5014counter register (or similar low latency, high accuracy clocks) on those targets
5015that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5016As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5017should only be used for small timings.
5018</p>
5019
5020<h5>Semantics:</h5>
5021
5022<p>
5023When directly supported, reading the cycle counter should not modify any memory.
5024Implementations are allowed to either return a application specific value or a
5025system wide value. On backends without support, this is lowered to a constant 0.
5026</p>
5027
5028</div>
5029
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5030<!-- ======================================================================= -->
5031<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5032 <a name="int_libc">Standard C Library Intrinsics</a>
5033</div>
5034
5035<div class="doc_text">
5036<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5037LLVM provides intrinsics for a few important standard C library functions.
5038These intrinsics allow source-language front-ends to pass information about the
5039alignment of the pointer arguments to the code generator, providing opportunity
5040for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5041</p>
5042
5043</div>
5044
5045<!-- _______________________________________________________________________ -->
5046<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5047 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5048</div>
5049
5050<div class="doc_text">
5051
5052<h5>Syntax:</h5>
5053<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5054 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5055 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5056 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5057 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5058</pre>
5059
5060<h5>Overview:</h5>
5061
5062<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5063The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5064location to the destination location.
5065</p>
5066
5067<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5068Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5069intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5070</p>
5071
5072<h5>Arguments:</h5>
5073
5074<p>
5075The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5076the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5077specifying the number of bytes to copy, and the fourth argument is the alignment
5078of the source and destination locations.
5079</p>
5080
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5081<p>
5082If 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]5083the caller guarantees that both the source and destination pointers are aligned
5084to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5085</p>
5086
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5087<h5>Semantics:</h5>
5088
5089<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5090The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5091location to the destination location, which are not allowed to overlap. It
5092copies "len" bytes of memory over. If the argument is known to be aligned to
5093some boundary, this can be specified as the fourth argument, otherwise it should
5094be set to 0 or 1.
5095</p>
5096</div>
5097
5098
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5099<!-- _______________________________________________________________________ -->
5100<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5101 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5102</div>
5103
5104<div class="doc_text">
5105
5106<h5>Syntax:</h5>
5107<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5108 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5109 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5110 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5111 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5112</pre>
5113
5114<h5>Overview:</h5>
5115
5116<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5117The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5118location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5119'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5120</p>
5121
5122<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5123Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5124intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5125</p>
5126
5127<h5>Arguments:</h5>
5128
5129<p>
5130The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5131the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5132specifying the number of bytes to copy, and the fourth argument is the alignment
5133of the source and destination locations.
5134</p>
5135
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5136<p>
5137If 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]5138the caller guarantees that the source and destination pointers are aligned to
5139that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5140</p>
5141
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5142<h5>Semantics:</h5>
5143
5144<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5145The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5146location to the destination location, which may overlap. It
5147copies "len" bytes of memory over. If the argument is known to be aligned to
5148some boundary, this can be specified as the fourth argument, otherwise it should
5149be set to 0 or 1.
5150</p>
5151</div>
5152
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5153
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5154<!-- _______________________________________________________________________ -->
5155<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5156 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5157</div>
5158
5159<div class="doc_text">
5160
5161<h5>Syntax:</h5>
5162<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5163 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5164 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5165 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5166 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5167</pre>
5168
5169<h5>Overview:</h5>
5170
5171<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5172The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5173byte value.
5174</p>
5175
5176<p>
5177Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5178does not return a value, and takes an extra alignment argument.
5179</p>
5180
5181<h5>Arguments:</h5>
5182
5183<p>
5184The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5185byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5186argument specifying the number of bytes to fill, and the fourth argument is the
5187known alignment of destination location.
5188</p>
5189
5190<p>
5191If 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]5192the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5193</p>
5194
5195<h5>Semantics:</h5>
5196
5197<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5198The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5199the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5200destination location. If the argument is known to be aligned to some boundary,
5201this can be specified as the fourth argument, otherwise it should be set to 0 or
52021.
5203</p>
5204</div>
5205
5206
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5207<!-- _______________________________________________________________________ -->
5208<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5209 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5210</div>
5211
5212<div class="doc_text">
5213
5214<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5215<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]5216floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5217types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5218<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5219 declare float @llvm.sqrt.f32(float %Val)
5220 declare double @llvm.sqrt.f64(double %Val)
5221 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5222 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5223 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5224</pre>
5225
5226<h5>Overview:</h5>
5227
5228<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5229The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5230returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5231<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5232negative numbers other than -0.0 (which allows for better optimization, because
5233there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5234defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5235</p>
5236
5237<h5>Arguments:</h5>
5238
5239<p>
5240The argument and return value are floating point numbers of the same type.
5241</p>
5242
5243<h5>Semantics:</h5>
5244
5245<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5246This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5247floating point number.
5248</p>
5249</div>
5250
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5251<!-- _______________________________________________________________________ -->
5252<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5253 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5254</div>
5255
5256<div class="doc_text">
5257
5258<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5259<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]5260floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5261types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5262<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5263 declare float @llvm.powi.f32(float %Val, i32 %power)
5264 declare double @llvm.powi.f64(double %Val, i32 %power)
5265 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5266 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5267 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5268</pre>
5269
5270<h5>Overview:</h5>
5271
5272<p>
5273The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5274specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5275multiplications is not defined. When a vector of floating point type is
5276used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5277</p>
5278
5279<h5>Arguments:</h5>
5280
5281<p>
5282The second argument is an integer power, and the first is a value to raise to
5283that power.
5284</p>
5285
5286<h5>Semantics:</h5>
5287
5288<p>
5289This function returns the first value raised to the second power with an
5290unspecified sequence of rounding operations.</p>
5291</div>
5292
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5293<!-- _______________________________________________________________________ -->
5294<div class="doc_subsubsection">
5295 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5296</div>
5297
5298<div class="doc_text">
5299
5300<h5>Syntax:</h5>
5301<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5302floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5303types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5304<pre>
5305 declare float @llvm.sin.f32(float %Val)
5306 declare double @llvm.sin.f64(double %Val)
5307 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5308 declare fp128 @llvm.sin.f128(fp128 %Val)
5309 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5310</pre>
5311
5312<h5>Overview:</h5>
5313
5314<p>
5315The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5316</p>
5317
5318<h5>Arguments:</h5>
5319
5320<p>
5321The argument and return value are floating point numbers of the same type.
5322</p>
5323
5324<h5>Semantics:</h5>
5325
5326<p>
5327This function returns the sine of the specified operand, returning the
5328same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5329conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5330</div>
5331
5332<!-- _______________________________________________________________________ -->
5333<div class="doc_subsubsection">
5334 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5335</div>
5336
5337<div class="doc_text">
5338
5339<h5>Syntax:</h5>
5340<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5341floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5342types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5343<pre>
5344 declare float @llvm.cos.f32(float %Val)
5345 declare double @llvm.cos.f64(double %Val)
5346 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5347 declare fp128 @llvm.cos.f128(fp128 %Val)
5348 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5349</pre>
5350
5351<h5>Overview:</h5>
5352
5353<p>
5354The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5355</p>
5356
5357<h5>Arguments:</h5>
5358
5359<p>
5360The argument and return value are floating point numbers of the same type.
5361</p>
5362
5363<h5>Semantics:</h5>
5364
5365<p>
5366This function returns the cosine of the specified operand, returning the
5367same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5368conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5369</div>
5370
5371<!-- _______________________________________________________________________ -->
5372<div class="doc_subsubsection">
5373 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5374</div>
5375
5376<div class="doc_text">
5377
5378<h5>Syntax:</h5>
5379<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5380floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5381types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5382<pre>
5383 declare float @llvm.pow.f32(float %Val, float %Power)
5384 declare double @llvm.pow.f64(double %Val, double %Power)
5385 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5386 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5387 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5388</pre>
5389
5390<h5>Overview:</h5>
5391
5392<p>
5393The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5394specified (positive or negative) power.
5395</p>
5396
5397<h5>Arguments:</h5>
5398
5399<p>
5400The second argument is a floating point power, and the first is a value to
5401raise to that power.
5402</p>
5403
5404<h5>Semantics:</h5>
5405
5406<p>
5407This function returns the first value raised to the second power,
5408returning the
5409same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5410conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5411</div>
5412
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5413
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5414<!-- ======================================================================= -->
5415<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5416 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5417</div>
5418
5419<div class="doc_text">
5420<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5421LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5422These allow efficient code generation for some algorithms.
5423</p>
5424
5425</div>
5426
5427<!-- _______________________________________________________________________ -->
5428<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5429 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5430</div>
5431
5432<div class="doc_text">
5433
5434<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5435<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5436type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5437<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5438 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5439 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5440 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5441</pre>
5442
5443<h5>Overview:</h5>
5444
5445<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5446The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5447values with an even number of bytes (positive multiple of 16 bits). These are
5448useful for performing operations on data that is not in the target's native
5449byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5450</p>
5451
5452<h5>Semantics:</h5>
5453
5454<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5455The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5456and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5457intrinsic returns an i32 value that has the four bytes of the input i32
5458swapped, 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]5459i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5460<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5461additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5462</p>
5463
5464</div>
5465
5466<!-- _______________________________________________________________________ -->
5467<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5468 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5469</div>
5470
5471<div class="doc_text">
5472
5473<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5474<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]5475width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5476<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5477 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5478 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5479 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5480 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5481 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5482</pre>
5483
5484<h5>Overview:</h5>
5485
5486<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5487The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5488value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5489</p>
5490
5491<h5>Arguments:</h5>
5492
5493<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5494The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5495integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5496</p>
5497
5498<h5>Semantics:</h5>
5499
5500<p>
5501The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5502</p>
5503</div>
5504
5505<!-- _______________________________________________________________________ -->
5506<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5507 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5508</div>
5509
5510<div class="doc_text">
5511
5512<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5513<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]5514integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5515<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5516 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5517 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5518 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5519 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5520 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5521</pre>
5522
5523<h5>Overview:</h5>
5524
5525<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5526The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5527leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5528</p>
5529
5530<h5>Arguments:</h5>
5531
5532<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5533The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5534integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5535</p>
5536
5537<h5>Semantics:</h5>
5538
5539<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5540The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5541in 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]5542of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5543</p>
5544</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5545
5546
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5547
5548<!-- _______________________________________________________________________ -->
5549<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5550 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5551</div>
5552
5553<div class="doc_text">
5554
5555<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5556<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]5557integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5558<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5559 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5560 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5561 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5562 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5563 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5564</pre>
5565
5566<h5>Overview:</h5>
5567
5568<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5569The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5570trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5571</p>
5572
5573<h5>Arguments:</h5>
5574
5575<p>
5576The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5577integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5578</p>
5579
5580<h5>Semantics:</h5>
5581
5582<p>
5583The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5584in a variable. If the src == 0 then the result is the size in bits of the type
5585of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5586</p>
5587</div>
5588
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5589<!-- _______________________________________________________________________ -->
5590<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5591 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5592</div>
5593
5594<div class="doc_text">
5595
5596<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5597<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5598on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5599<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5600 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5601 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5602</pre>
5603
5604<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5605<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5606range of bits from an integer value and returns them in the same bit width as
5607the original value.</p>
5608
5609<h5>Arguments:</h5>
5610<p>The first argument, <tt>%val</tt> and the result may be integer types of
5611any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5612arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5613
5614<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5615<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5616of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5617<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5618operates in forward mode.</p>
5619<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5620right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5621only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5622<ol>
5623 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5624 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5625 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5626 to determine the number of bits to retain.</li>
5627 <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]5628 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5629</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5630<p>In reverse mode, a similar computation is made except that the bits are
5631returned in the reverse order. So, for example, if <tt>X</tt> has the value
5632<tt>i16 0x0ACF (101011001111)</tt> and we apply
5633<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5634<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5635</div>
5636
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5637<div class="doc_subsubsection">
5638 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5639</div>
5640
5641<div class="doc_text">
5642
5643<h5>Syntax:</h5>
5644<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5645on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5646<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5647 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5648 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]5649</pre>
5650
5651<h5>Overview:</h5>
5652<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5653of bits in an integer value with another integer value. It returns the integer
5654with the replaced bits.</p>
5655
5656<h5>Arguments:</h5>
5657<p>The first argument, <tt>%val</tt> and the result may be integer types of
5658any bit width but they must have the same bit width. <tt>%val</tt> is the value
5659whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5660integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5661type since they specify only a bit index.</p>
5662
5663<h5>Semantics:</h5>
5664<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5665of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5666<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5667operates in forward mode.</p>
5668<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5669truncating it down to the size of the replacement area or zero extending it
5670up to that size.</p>
5671<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5672are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5673in <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]5674to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5675<p>In reverse mode, a similar computation is made except that the bits are
5676reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5677<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]5678<h5>Examples:</h5>
5679<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5680 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5681 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5682 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5683 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5684 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5685</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5686</div>
5687
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5688<!-- ======================================================================= -->
5689<div class="doc_subsection">
5690 <a name="int_debugger">Debugger Intrinsics</a>
5691</div>
5692
5693<div class="doc_text">
5694<p>
5695The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5696are described in the <a
5697href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5698Debugging</a> document.
5699</p>
5700</div>
5701
5702
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5703<!-- ======================================================================= -->
5704<div class="doc_subsection">
5705 <a name="int_eh">Exception Handling Intrinsics</a>
5706</div>
5707
5708<div class="doc_text">
5709<p> The LLVM exception handling intrinsics (which all start with
5710<tt>llvm.eh.</tt> prefix), are described in the <a
5711href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5712Handling</a> document. </p>
5713</div>
5714
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5715<!-- ======================================================================= -->
5716<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5717 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5718</div>
5719
5720<div class="doc_text">
5721<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5722 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5723 the <tt>nest</tt> attribute, from a function. The result is a callable
5724 function pointer lacking the nest parameter - the caller does not need
5725 to provide a value for it. Instead, the value to use is stored in
5726 advance in a "trampoline", a block of memory usually allocated
5727 on the stack, which also contains code to splice the nest value into the
5728 argument list. This is used to implement the GCC nested function address
5729 extension.
5730</p>
5731<p>
5732 For example, if the function is
5733 <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]5734 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]5735<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5736 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5737 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5738 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5739 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5740</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5741 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5742 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5743</div>
5744
5745<!-- _______________________________________________________________________ -->
5746<div class="doc_subsubsection">
5747 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5748</div>
5749<div class="doc_text">
5750<h5>Syntax:</h5>
5751<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5752declare 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]5753</pre>
5754<h5>Overview:</h5>
5755<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5756 This fills the memory pointed to by <tt>tramp</tt> with code
5757 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5758</p>
5759<h5>Arguments:</h5>
5760<p>
5761 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5762 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5763 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5764 intrinsic. Note that the size and the alignment are target-specific - LLVM
5765 currently provides no portable way of determining them, so a front-end that
5766 generates this intrinsic needs to have some target-specific knowledge.
5767 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]5768</p>
5769<h5>Semantics:</h5>
5770<p>
5771 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5772 dependent code, turning it into a function. A pointer to this function is
5773 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5774 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5775 before being called. The new function's signature is the same as that of
5776 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5777 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5778 of pointer type. Calling the new function is equivalent to calling
5779 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5780 missing <tt>nest</tt> argument. If, after calling
5781 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5782 modified, then the effect of any later call to the returned function pointer is
5783 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5784</p>
5785</div>
5786
5787<!-- ======================================================================= -->
5788<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5789 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5790</div>
5791
5792<div class="doc_text">
5793<p>
5794 These intrinsic functions expand the "universal IR" of LLVM to represent
5795 hardware constructs for atomic operations and memory synchronization. This
5796 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5797 is aimed at a low enough level to allow any programming models or APIs
5798 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5799 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5800 hardware behavior. Just as hardware provides a "universal IR" for source
5801 languages, it also provides a starting point for developing a "universal"
5802 atomic operation and synchronization IR.
5803</p>
5804<p>
5805 These do <em>not</em> form an API such as high-level threading libraries,
5806 software transaction memory systems, atomic primitives, and intrinsic
5807 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5808 application libraries. The hardware interface provided by LLVM should allow
5809 a clean implementation of all of these APIs and parallel programming models.
5810 No one model or paradigm should be selected above others unless the hardware
5811 itself ubiquitously does so.
5812
5813</p>
5814</div>
5815
5816<!-- _______________________________________________________________________ -->
5817<div class="doc_subsubsection">
5818 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5819</div>
5820<div class="doc_text">
5821<h5>Syntax:</h5>
5822<pre>
5823declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5824i1 &lt;device&gt; )
5825
5826</pre>
5827<h5>Overview:</h5>
5828<p>
5829 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5830 specific pairs of memory access types.
5831</p>
5832<h5>Arguments:</h5>
5833<p>
5834 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5835 The first four arguments enables a specific barrier as listed below. The fith
5836 argument specifies that the barrier applies to io or device or uncached memory.
5837
5838</p>
5839 <ul>
5840 <li><tt>ll</tt>: load-load barrier</li>
5841 <li><tt>ls</tt>: load-store barrier</li>
5842 <li><tt>sl</tt>: store-load barrier</li>
5843 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5844 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5845 </ul>
5846<h5>Semantics:</h5>
5847<p>
5848 This intrinsic causes the system to enforce some ordering constraints upon
5849 the loads and stores of the program. This barrier does not indicate
5850 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5851 which they occur. For any of the specified pairs of load and store operations
5852 (f.ex. load-load, or store-load), all of the first operations preceding the
5853 barrier will complete before any of the second operations succeeding the
5854 barrier begin. Specifically the semantics for each pairing is as follows:
5855</p>
5856 <ul>
5857 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5858 after the barrier begins.</li>
5859
5860 <li><tt>ls</tt>: All loads before the barrier must complete before any
5861 store after the barrier begins.</li>
5862 <li><tt>ss</tt>: All stores before the barrier must complete before any
5863 store after the barrier begins.</li>
5864 <li><tt>sl</tt>: All stores before the barrier must complete before any
5865 load after the barrier begins.</li>
5866 </ul>
5867<p>
5868 These semantics are applied with a logical "and" behavior when more than one
5869 is enabled in a single memory barrier intrinsic.
5870</p>
5871<p>
5872 Backends may implement stronger barriers than those requested when they do not
5873 support as fine grained a barrier as requested. Some architectures do not
5874 need all types of barriers and on such architectures, these become noops.
5875</p>
5876<h5>Example:</h5>
5877<pre>
5878%ptr = malloc i32
5879 store i32 4, %ptr
5880
5881%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5882 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5883 <i>; guarantee the above finishes</i>
5884 store i32 8, %ptr <i>; before this begins</i>
5885</pre>
5886</div>
5887
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5888<!-- _______________________________________________________________________ -->
5889<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5890 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5891</div>
5892<div class="doc_text">
5893<h5>Syntax:</h5>
5894<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5895 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5896 any integer bit width and for different address spaces. Not all targets
5897 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5898
5899<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5900declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5901declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5902declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5903declare 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]5904
5905</pre>
5906<h5>Overview:</h5>
5907<p>
5908 This loads a value in memory and compares it to a given value. If they are
5909 equal, it stores a new value into the memory.
5910</p>
5911<h5>Arguments:</h5>
5912<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5913 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5914 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5915 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5916 this integer type. While any bit width integer may be used, targets may only
5917 lower representations they support in hardware.
5918
5919</p>
5920<h5>Semantics:</h5>
5921<p>
5922 This entire intrinsic must be executed atomically. It first loads the value
5923 in memory pointed to by <tt>ptr</tt> and compares it with the value
5924 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5925 loaded value is yielded in all cases. This provides the equivalent of an
5926 atomic compare-and-swap operation within the SSA framework.
5927</p>
5928<h5>Examples:</h5>
5929
5930<pre>
5931%ptr = malloc i32
5932 store i32 4, %ptr
5933
5934%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5935%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5936 <i>; yields {i32}:result1 = 4</i>
5937%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5938%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5939
5940%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5941%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5942 <i>; yields {i32}:result2 = 8</i>
5943%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5944
5945%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5946</pre>
5947</div>
5948
5949<!-- _______________________________________________________________________ -->
5950<div class="doc_subsubsection">
5951 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5952</div>
5953<div class="doc_text">
5954<h5>Syntax:</h5>
5955
5956<p>
5957 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5958 integer bit width. Not all targets support all bit widths however.</p>
5959<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5960declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5961declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5962declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5963declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5964
5965</pre>
5966<h5>Overview:</h5>
5967<p>
5968 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5969 the value from memory. It then stores the value in <tt>val</tt> in the memory
5970 at <tt>ptr</tt>.
5971</p>
5972<h5>Arguments:</h5>
5973
5974<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5975 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5976 <tt>val</tt> argument and the result must be integers of the same bit width.
5977 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5978 integer type. The targets may only lower integer representations they
5979 support.
5980</p>
5981<h5>Semantics:</h5>
5982<p>
5983 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
5984 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
5985 equivalent of an atomic swap operation within the SSA framework.
5986
5987</p>
5988<h5>Examples:</h5>
5989<pre>
5990%ptr = malloc i32
5991 store i32 4, %ptr
5992
5993%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5994%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5995 <i>; yields {i32}:result1 = 4</i>
5996%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5997%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5998
5999%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6000%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6001 <i>; yields {i32}:result2 = 8</i>
6002
6003%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6004%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6005</pre>
6006</div>
6007
6008<!-- _______________________________________________________________________ -->
6009<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6010 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6011
6012</div>
6013<div class="doc_text">
6014<h5>Syntax:</h5>
6015<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6016 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]6017 integer bit width. Not all targets support all bit widths however.</p>
6018<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6019declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6020declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6021declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6022declare 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]6023
6024</pre>
6025<h5>Overview:</h5>
6026<p>
6027 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6028 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6029</p>
6030<h5>Arguments:</h5>
6031<p>
6032
6033 The intrinsic takes two arguments, the first a pointer to an integer value
6034 and the second an integer value. The result is also an integer value. These
6035 integer types can have any bit width, but they must all have the same bit
6036 width. The targets may only lower integer representations they support.
6037</p>
6038<h5>Semantics:</h5>
6039<p>
6040 This intrinsic does a series of operations atomically. It first loads the
6041 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6042 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6043</p>
6044
6045<h5>Examples:</h5>
6046<pre>
6047%ptr = malloc i32
6048 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6049%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6050 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6051%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6052 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6053%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6054 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6055%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6056</pre>
6057</div>
6058
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6059<!-- _______________________________________________________________________ -->
6060<div class="doc_subsubsection">
6061 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6062
6063</div>
6064<div class="doc_text">
6065<h5>Syntax:</h5>
6066<p>
6067 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]6068 any integer bit width and for different address spaces. Not all targets
6069 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6070<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6071declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6072declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6073declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6074declare 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]6075
6076</pre>
6077<h5>Overview:</h5>
6078<p>
6079 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6080 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6081</p>
6082<h5>Arguments:</h5>
6083<p>
6084
6085 The intrinsic takes two arguments, the first a pointer to an integer value
6086 and the second an integer value. The result is also an integer value. These
6087 integer types can have any bit width, but they must all have the same bit
6088 width. The targets may only lower integer representations they support.
6089</p>
6090<h5>Semantics:</h5>
6091<p>
6092 This intrinsic does a series of operations atomically. It first loads the
6093 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6094 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6095</p>
6096
6097<h5>Examples:</h5>
6098<pre>
6099%ptr = malloc i32
6100 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6101%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6102 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6103%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6104 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6105%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6106 <i>; yields {i32}:result3 = 2</i>
6107%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6108</pre>
6109</div>
6110
6111<!-- _______________________________________________________________________ -->
6112<div class="doc_subsubsection">
6113 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6114 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6115 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6116 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6117
6118</div>
6119<div class="doc_text">
6120<h5>Syntax:</h5>
6121<p>
6122 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6123 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6124 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6125 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6126<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6127declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6128declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6129declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6130declare 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]6131
6132</pre>
6133
6134<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6135declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6136declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6137declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6138declare 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]6139
6140</pre>
6141
6142<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6143declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6144declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6145declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6146declare 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]6147
6148</pre>
6149
6150<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6151declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6152declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6153declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6154declare 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]6155
6156</pre>
6157<h5>Overview:</h5>
6158<p>
6159 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6160 the value stored in memory at <tt>ptr</tt>. It yields the original value
6161 at <tt>ptr</tt>.
6162</p>
6163<h5>Arguments:</h5>
6164<p>
6165
6166 These intrinsics take two arguments, the first a pointer to an integer value
6167 and the second an integer value. The result is also an integer value. These
6168 integer types can have any bit width, but they must all have the same bit
6169 width. The targets may only lower integer representations they support.
6170</p>
6171<h5>Semantics:</h5>
6172<p>
6173 These intrinsics does a series of operations atomically. They first load the
6174 value stored at <tt>ptr</tt>. They then do the bitwise operation
6175 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6176 value stored at <tt>ptr</tt>.
6177</p>
6178
6179<h5>Examples:</h5>
6180<pre>
6181%ptr = malloc i32
6182 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6183%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6184 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6185%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6186 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6187%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6188 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6189%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6190 <i>; yields {i32}:result3 = FF</i>
6191%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6192</pre>
6193</div>
6194
6195
6196<!-- _______________________________________________________________________ -->
6197<div class="doc_subsubsection">
6198 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6199 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6200 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6201 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6202
6203</div>
6204<div class="doc_text">
6205<h5>Syntax:</h5>
6206<p>
6207 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6208 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6209 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6210 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6211 support all bit widths however.</p>
6212<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6213declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6214declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6215declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6216declare 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]6217
6218</pre>
6219
6220<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6221declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6222declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6223declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6224declare 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]6225
6226</pre>
6227
6228<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6229declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6230declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6231declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6232declare 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]6233
6234</pre>
6235
6236<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6237declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6238declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6239declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6240declare 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]6241
6242</pre>
6243<h5>Overview:</h5>
6244<p>
6245 These intrinsics takes the signed or unsigned minimum or maximum of
6246 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6247 original value at <tt>ptr</tt>.
6248</p>
6249<h5>Arguments:</h5>
6250<p>
6251
6252 These intrinsics take two arguments, the first a pointer to an integer value
6253 and the second an integer value. The result is also an integer value. These
6254 integer types can have any bit width, but they must all have the same bit
6255 width. The targets may only lower integer representations they support.
6256</p>
6257<h5>Semantics:</h5>
6258<p>
6259 These intrinsics does a series of operations atomically. They first load the
6260 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6261 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6262 the original value stored at <tt>ptr</tt>.
6263</p>
6264
6265<h5>Examples:</h5>
6266<pre>
6267%ptr = malloc i32
6268 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6269%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6270 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6271%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6272 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6273%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6274 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6275%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6276 <i>; yields {i32}:result3 = 8</i>
6277%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6278</pre>
6279</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6280
6281<!-- ======================================================================= -->
6282<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6283 <a name="int_general">General Intrinsics</a>
6284</div>
6285
6286<div class="doc_text">
6287<p> This class of intrinsics is designed to be generic and has
6288no specific purpose. </p>
6289</div>
6290
6291<!-- _______________________________________________________________________ -->
6292<div class="doc_subsubsection">
6293 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6294</div>
6295
6296<div class="doc_text">
6297
6298<h5>Syntax:</h5>
6299<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6300 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]6301</pre>
6302
6303<h5>Overview:</h5>
6304
6305<p>
6306The '<tt>llvm.var.annotation</tt>' intrinsic
6307</p>
6308
6309<h5>Arguments:</h5>
6310
6311<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6312The first argument is a pointer to a value, the second is a pointer to a
6313global string, the third is a pointer to a global string which is the source
6314file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6315</p>
6316
6317<h5>Semantics:</h5>
6318
6319<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6320This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6321This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6322annotations. These have no other defined use, they are ignored by code
6323generation and optimization.
6324</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6325</div>
6326
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6327<!-- _______________________________________________________________________ -->
6328<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6329 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6330</div>
6331
6332<div class="doc_text">
6333
6334<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6335<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6336any integer bit width.
6337</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6338<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6339 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6340 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6341 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6342 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6343 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]6344</pre>
6345
6346<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6347
6348<p>
6349The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6350</p>
6351
6352<h5>Arguments:</h5>
6353
6354<p>
6355The first argument is an integer value (result of some expression),
6356the second is a pointer to a global string, the third is a pointer to a global
6357string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6358It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6359</p>
6360
6361<h5>Semantics:</h5>
6362
6363<p>
6364This intrinsic allows annotations to be put on arbitrary expressions
6365with arbitrary strings. This can be useful for special purpose optimizations
6366that want to look for these annotations. These have no other defined use, they
6367are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6368</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6369</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6370
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6371<!-- _______________________________________________________________________ -->
6372<div class="doc_subsubsection">
6373 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6374</div>
6375
6376<div class="doc_text">
6377
6378<h5>Syntax:</h5>
6379<pre>
6380 declare void @llvm.trap()
6381</pre>
6382
6383<h5>Overview:</h5>
6384
6385<p>
6386The '<tt>llvm.trap</tt>' intrinsic
6387</p>
6388
6389<h5>Arguments:</h5>
6390
6391<p>
6392None
6393</p>
6394
6395<h5>Semantics:</h5>
6396
6397<p>
6398This intrinsics is lowered to the target dependent trap instruction. If the
6399target does not have a trap instruction, this intrinsic will be lowered to the
6400call of the abort() function.
6401</p>
6402</div>
6403
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6404<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6405<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6406<address>
6407 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6408 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6409 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6410 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6411
6412 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6413 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6414 Last modified: $Date$
6415</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6416
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6417</body>
6418</html>