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gerrit-public.fairphone.software / toolchain / llvm-project / 2d8b9a8834cd27d00b0fd402a26d7b579a514a74 / . / llvm / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
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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>
Anton Korobeynikov546ea7e2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]29 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]30 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]31 </ol>
32 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]33 <li><a href="#typesystem">Type System</a>
34 <ol>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]35 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]36 <ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]38 </ol>
39 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]40 <li><a href="#t_derived">Derived Types</a>
41 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]42 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]43 <li><a href="#t_function">Function Type</a></li>
44 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]45 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]46 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]47 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]48 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]49 </ol>
50 </li>
51 </ol>
52 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]53 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]54 <ol>
55 <li><a href="#simpleconstants">Simple Constants</a>
56 <li><a href="#aggregateconstants">Aggregate Constants</a>
57 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
58 <li><a href="#undefvalues">Undefined Values</a>
59 <li><a href="#constantexprs">Constant Expressions</a>
60 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]61 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]62 <li><a href="#othervalues">Other Values</a>
63 <ol>
64 <li><a href="#inlineasm">Inline Assembler Expressions</a>
65 </ol>
66 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#instref">Instruction Reference</a>
68 <ol>
69 <li><a href="#terminators">Terminator Instructions</a>
70 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
72 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]73 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
74 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]75 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]76 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]77 </ol>
78 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]79 <li><a href="#binaryops">Binary Operations</a>
80 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
82 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
83 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]84 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
85 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
86 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]87 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
88 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
89 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]90 </ol>
91 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]92 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
93 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]94 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
95 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
96 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]97 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]98 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]99 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]102 <li><a href="#vectorops">Vector Operations</a>
103 <ol>
104 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
105 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
106 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]109 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]110 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]111 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
112 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
113 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]114 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
115 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
116 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]117 </ol>
118 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]119 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]120 <ol>
121 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
122 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
123 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
124 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
125 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]126 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
127 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
128 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
129 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]130 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
131 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]132 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]133 </ol>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#otherops">Other Operations</a>
135 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]136 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
137 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]138 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]139 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]141 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]142 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]143 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]144 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]146 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]147 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
149 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]150 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
151 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
152 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]155 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
156 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]157 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
158 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
159 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]160 </ol>
161 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]162 <li><a href="#int_codegen">Code Generator Intrinsics</a>
163 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]164 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
165 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
166 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
167 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
168 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
169 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
170 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]171 </ol>
172 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]173 <li><a href="#int_libc">Standard C Library Intrinsics</a>
174 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]175 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
176 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
177 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]180 </ol>
181 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]182 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]183 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]184 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]185 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
186 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
187 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]188 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
189 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]190 </ol>
191 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]192 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]193 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]194 </ol>
195 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]196</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]197
198<div class="doc_author">
199 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
200 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]201</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]202
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]203<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]204<div class="doc_section"> <a name="abstract">Abstract </a></div>
205<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]206
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]207<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]208<p>This document is a reference manual for the LLVM assembly language.
209LLVM is an SSA based representation that provides type safety,
210low-level operations, flexibility, and the capability of representing
211'all' high-level languages cleanly. It is the common code
212representation used throughout all phases of the LLVM compilation
213strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]214</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]215
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]216<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]217<div class="doc_section"> <a name="introduction">Introduction</a> </div>
218<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]219
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]220<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]221
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]222<p>The LLVM code representation is designed to be used in three
223different forms: as an in-memory compiler IR, as an on-disk bytecode
224representation (suitable for fast loading by a Just-In-Time compiler),
225and as a human readable assembly language representation. This allows
226LLVM to provide a powerful intermediate representation for efficient
227compiler transformations and analysis, while providing a natural means
228to debug and visualize the transformations. The three different forms
229of LLVM are all equivalent. This document describes the human readable
230representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]231
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]232<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]233while being expressive, typed, and extensible at the same time. It
234aims to be a "universal IR" of sorts, by being at a low enough level
235that high-level ideas may be cleanly mapped to it (similar to how
236microprocessors are "universal IR's", allowing many source languages to
237be mapped to them). By providing type information, LLVM can be used as
238the target of optimizations: for example, through pointer analysis, it
239can be proven that a C automatic variable is never accessed outside of
240the current function... allowing it to be promoted to a simple SSA
241value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]242
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]243</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]244
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]245<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]246<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]247
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]248<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]249
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]250<p>It is important to note that this document describes 'well formed'
251LLVM assembly language. There is a difference between what the parser
252accepts and what is considered 'well formed'. For example, the
253following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]254
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]255<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]256<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]257%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]258</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]259</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]260
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]261<p>...because the definition of <tt>%x</tt> does not dominate all of
262its uses. The LLVM infrastructure provides a verification pass that may
263be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]264automatically run by the parser after parsing input assembly and by
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]265the optimizer before it outputs bytecode. The violations pointed out
266by the verifier pass indicate bugs in transformation passes or input to
267the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]268</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]270<!-- Describe the typesetting conventions here. --> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]271
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]272<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]273<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]274<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]275
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]276<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]277
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]278<p>LLVM uses three different forms of identifiers, for different
279purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]281<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]282 <li>Named values are represented as a string of characters with a '%' prefix.
283 For example, %foo, %DivisionByZero, %a.really.long.identifier. The actual
284 regular expression used is '<tt>%[a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
285 Identifiers which require other characters in their names can be surrounded
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]286 with quotes. In this way, anything except a <tt>&quot;</tt> character can be used
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]287 in a name.</li>
288
289 <li>Unnamed values are represented as an unsigned numeric value with a '%'
290 prefix. For example, %12, %2, %44.</li>
291
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]292 <li>Constants, which are described in a <a href="#constants">section about
293 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]294</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]295
296<p>LLVM requires that values start with a '%' sign for two reasons: Compilers
297don't need to worry about name clashes with reserved words, and the set of
298reserved words may be expanded in the future without penalty. Additionally,
299unnamed identifiers allow a compiler to quickly come up with a temporary
300variable without having to avoid symbol table conflicts.</p>
301
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]302<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]303languages. There are keywords for different opcodes
304('<tt><a href="#i_add">add</a></tt>',
305 '<tt><a href="#i_bitcast">bitcast</a></tt>',
306 '<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]307href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]308and others. These reserved words cannot conflict with variable names, because
309none of them start with a '%' character.</p>
310
311<p>Here is an example of LLVM code to multiply the integer variable
312'<tt>%X</tt>' by 8:</p>
313
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]314<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]315
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]316<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]317<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]318%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]319</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]320</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]321
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]322<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]323
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]324<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]325<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]326%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]327</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]328</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]329
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]330<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]331
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]332<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]333<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]334<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
335<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
336%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]337</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]338</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]339
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]340<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
341important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]342
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]343<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]344
345 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
346 line.</li>
347
348 <li>Unnamed temporaries are created when the result of a computation is not
349 assigned to a named value.</li>
350
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]351 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]352
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]353</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]354
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]355<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]356demonstrating instructions, we will follow an instruction with a comment that
357defines the type and name of value produced. Comments are shown in italic
358text.</p>
359
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]360</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]361
362<!-- *********************************************************************** -->
363<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
364<!-- *********************************************************************** -->
365
366<!-- ======================================================================= -->
367<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
368</div>
369
370<div class="doc_text">
371
372<p>LLVM programs are composed of "Module"s, each of which is a
373translation unit of the input programs. Each module consists of
374functions, global variables, and symbol table entries. Modules may be
375combined together with the LLVM linker, which merges function (and
376global variable) definitions, resolves forward declarations, and merges
377symbol table entries. Here is an example of the "hello world" module:</p>
378
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]379<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]380<pre><i>; Declare the string constant as a global constant...</i>
381<a href="#identifiers">%.LC0</a> = <a href="#linkage_internal">internal</a> <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]382 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]383
384<i>; External declaration of the puts function</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]385<a href="#functionstructure">declare</a> i32 %puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]386
387<i>; Definition of main function</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]388define i32 %main() { <i>; i32()* </i>
389 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]390 %cast210 = <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]391 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]392
393 <i>; Call puts function to write out the string to stdout...</i>
394 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]395 href="#i_call">call</a> i32 %puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]396 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]397 href="#i_ret">ret</a> i32 0<br>}<br>
398</pre>
399</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]400
401<p>This example is made up of a <a href="#globalvars">global variable</a>
402named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
403function, and a <a href="#functionstructure">function definition</a>
404for "<tt>main</tt>".</p>
405
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]406<p>In general, a module is made up of a list of global values,
407where both functions and global variables are global values. Global values are
408represented by a pointer to a memory location (in this case, a pointer to an
409array of char, and a pointer to a function), and have one of the following <a
410href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]411
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]412</div>
413
414<!-- ======================================================================= -->
415<div class="doc_subsection">
416 <a name="linkage">Linkage Types</a>
417</div>
418
419<div class="doc_text">
420
421<p>
422All Global Variables and Functions have one of the following types of linkage:
423</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]424
425<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]427 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428
429 <dd>Global values with internal linkage are only directly accessible by
430 objects in the current module. In particular, linking code into a module with
431 an internal global value may cause the internal to be renamed as necessary to
432 avoid collisions. Because the symbol is internal to the module, all
433 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]434 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]435 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]437 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]439 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
440 the same name when linkage occurs. This is typically used to implement
441 inline functions, templates, or other code which must be generated in each
442 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
443 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]444 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]446 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447
448 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
449 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]450 used for globals that may be emitted in multiple translation units, but that
451 are not guaranteed to be emitted into every translation unit that uses them.
452 One example of this are common globals in C, such as "<tt>int X;</tt>" at
453 global scope.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]454 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]455
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]456 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]457
458 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
459 pointer to array type. When two global variables with appending linkage are
460 linked together, the two global arrays are appended together. This is the
461 LLVM, typesafe, equivalent of having the system linker append together
462 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]463 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]465 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
466 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
467 until linked, if not linked, the symbol becomes null instead of being an
468 undefined reference.
469 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]470
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]471 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
473 <dd>If none of the above identifiers are used, the global is externally
474 visible, meaning that it participates in linkage and can be used to resolve
475 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]476 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]477</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]478
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]479 <p>
480 The next two types of linkage are targeted for Microsoft Windows platform
481 only. They are designed to support importing (exporting) symbols from (to)
482 DLLs.
483 </p>
484
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]485 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]486 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
487
488 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
489 or variable via a global pointer to a pointer that is set up by the DLL
490 exporting the symbol. On Microsoft Windows targets, the pointer name is
491 formed by combining <code>_imp__</code> and the function or variable name.
492 </dd>
493
494 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
495
496 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
497 pointer to a pointer in a DLL, so that it can be referenced with the
498 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
499 name is formed by combining <code>_imp__</code> and the function or variable
500 name.
501 </dd>
502
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]503</dl>
504
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]505<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]506variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
507variable and was linked with this one, one of the two would be renamed,
508preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
509external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]510outside of the current module.</p>
511<p>It is illegal for a function <i>declaration</i>
512to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]513or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]514<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
515linkages.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]516</div>
517
518<!-- ======================================================================= -->
519<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]520 <a name="callingconv">Calling Conventions</a>
521</div>
522
523<div class="doc_text">
524
525<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
526and <a href="#i_invoke">invokes</a> can all have an optional calling convention
527specified for the call. The calling convention of any pair of dynamic
528caller/callee must match, or the behavior of the program is undefined. The
529following calling conventions are supported by LLVM, and more may be added in
530the future:</p>
531
532<dl>
533 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
534
535 <dd>This calling convention (the default if no other calling convention is
536 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]537 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]538 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]539 </dd>
540
541 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
542
543 <dd>This calling convention attempts to make calls as fast as possible
544 (e.g. by passing things in registers). This calling convention allows the
545 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerc792eb32005-05-06 23:08:23 +0000[diff] [blame]546 without having to conform to an externally specified ABI. Implementations of
547 this convention should allow arbitrary tail call optimization to be supported.
548 This calling convention does not support varargs and requires the prototype of
549 all callees to exactly match the prototype of the function definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]550 </dd>
551
552 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
553
554 <dd>This calling convention attempts to make code in the caller as efficient
555 as possible under the assumption that the call is not commonly executed. As
556 such, these calls often preserve all registers so that the call does not break
557 any live ranges in the caller side. This calling convention does not support
558 varargs and requires the prototype of all callees to exactly match the
559 prototype of the function definition.
560 </dd>
561
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]562 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]563
564 <dd>Any calling convention may be specified by number, allowing
565 target-specific calling conventions to be used. Target specific calling
566 conventions start at 64.
567 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]568</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]569
570<p>More calling conventions can be added/defined on an as-needed basis, to
571support pascal conventions or any other well-known target-independent
572convention.</p>
573
574</div>
575
576<!-- ======================================================================= -->
577<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]578 <a name="visibility">Visibility Styles</a>
579</div>
580
581<div class="doc_text">
582
583<p>
584All Global Variables and Functions have one of the following visibility styles:
585</p>
586
587<dl>
588 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
589
590 <dd>On ELF, default visibility means that the declaration is visible to other
591 modules and, in shared libraries, means that the declared entity may be
592 overridden. On Darwin, default visibility means that the declaration is
593 visible to other modules. Default visibility corresponds to "external
594 linkage" in the language.
595 </dd>
596
597 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
598
599 <dd>Two declarations of an object with hidden visibility refer to the same
600 object if they are in the same shared object. Usually, hidden visibility
601 indicates that the symbol will not be placed into the dynamic symbol table,
602 so no other module (executable or shared library) can reference it
603 directly.
604 </dd>
605
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]606 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
607
608 <dd>On ELF, protected visibility indicates that the symbol will be placed in
609 the dynamic symbol table, but that references within the defining module will
610 bind to the local symbol. That is, the symbol cannot be overridden by another
611 module.
612 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]613</dl>
614
615</div>
616
617<!-- ======================================================================= -->
618<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]619 <a name="globalvars">Global Variables</a>
620</div>
621
622<div class="doc_text">
623
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]624<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]625instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]626an explicit section to be placed in, and may have an optional explicit alignment
627specified. A variable may be defined as "thread_local", which means that it
628will not be shared by threads (each thread will have a separated copy of the
629variable). A variable may be defined as a global "constant," which indicates
630that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]631optimization, allowing the global data to be placed in the read-only section of
632an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]633cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]634
635<p>
636LLVM explicitly allows <em>declarations</em> of global variables to be marked
637constant, even if the final definition of the global is not. This capability
638can be used to enable slightly better optimization of the program, but requires
639the language definition to guarantee that optimizations based on the
640'constantness' are valid for the translation units that do not include the
641definition.
642</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]643
644<p>As SSA values, global variables define pointer values that are in
645scope (i.e. they dominate) all basic blocks in the program. Global
646variables always define a pointer to their "content" type because they
647describe a region of memory, and all memory objects in LLVM are
648accessed through pointers.</p>
649
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]650<p>LLVM allows an explicit section to be specified for globals. If the target
651supports it, it will emit globals to the section specified.</p>
652
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]653<p>An explicit alignment may be specified for a global. If not present, or if
654the alignment is set to zero, the alignment of the global is set by the target
655to whatever it feels convenient. If an explicit alignment is specified, the
656global is forced to have at least that much alignment. All alignments must be
657a power of 2.</p>
658
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]659<p>For example, the following defines a global with an initializer, section,
660 and alignment:</p>
661
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]662<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]663<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]664%G = constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]665</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]666</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]667
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]668</div>
669
670
671<!-- ======================================================================= -->
672<div class="doc_subsection">
673 <a name="functionstructure">Functions</a>
674</div>
675
676<div class="doc_text">
677
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]678<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
679an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]680<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]681<a href="#callingconv">calling convention</a>, a return type, an optional
682<a href="#paramattrs">parameter attribute</a> for the return type, a function
683name, a (possibly empty) argument list (each with optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]684<a href="#paramattrs">parameter attributes</a>), an optional section, an
685optional alignment, an opening curly brace, a list of basic blocks, and a
686closing curly brace.
687
688LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
689optional <a href="#linkage">linkage type</a>, an optional
690<a href="#visibility">visibility style</a>, an optional
691<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]692<a href="#paramattrs">parameter attribute</a> for the return type, a function
693name, a possibly empty list of arguments, and an optional alignment.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]694
695<p>A function definition contains a list of basic blocks, forming the CFG for
696the function. Each basic block may optionally start with a label (giving the
697basic block a symbol table entry), contains a list of instructions, and ends
698with a <a href="#terminators">terminator</a> instruction (such as a branch or
699function return).</p>
700
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]701<p>The first basic block in a program is special in two ways: it is immediately
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]702executed on entrance to the function, and it is not allowed to have predecessor
703basic blocks (i.e. there can not be any branches to the entry block of a
704function). Because the block can have no predecessors, it also cannot have any
705<a href="#i_phi">PHI nodes</a>.</p>
706
707<p>LLVM functions are identified by their name and type signature. Hence, two
708functions with the same name but different parameter lists or return values are
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]709considered different functions, and LLVM will resolve references to each
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]710appropriately.</p>
711
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]712<p>LLVM allows an explicit section to be specified for functions. If the target
713supports it, it will emit functions to the section specified.</p>
714
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]715<p>An explicit alignment may be specified for a function. If not present, or if
716the alignment is set to zero, the alignment of the function is set by the target
717to whatever it feels convenient. If an explicit alignment is specified, the
718function is forced to have at least that much alignment. All alignments must be
719a power of 2.</p>
720
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]721</div>
722
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]723
724<!-- ======================================================================= -->
725<div class="doc_subsection">
726 <a name="aliasstructure">Aliases</a>
727</div>
728<div class="doc_text">
729 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikovb18f8f82007-04-28 13:45:00 +0000[diff] [blame]730 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]731 optional <a href="#linkage">linkage type</a>, and an
732 optional <a href="#visibility">visibility style</a>.</p>
733
734 <h5>Syntax:</h5>
735
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]736<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame^]737<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]738@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame^]739</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]740</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]741
742</div>
743
744
745
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]746<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]747<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
748<div class="doc_text">
749 <p>The return type and each parameter of a function type may have a set of
750 <i>parameter attributes</i> associated with them. Parameter attributes are
751 used to communicate additional information about the result or parameters of
752 a function. Parameter attributes are considered to be part of the function
753 type so two functions types that differ only by the parameter attributes
754 are different function types.</p>
755
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]756 <p>Parameter attributes are simple keywords that follow the type specified. If
757 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]758 example:</p>
759
760<div class="doc_code">
761<pre>
762%someFunc = i16 (i8 sext %someParam) zext
763%someFunc = i16 (i8 zext %someParam) zext
764</pre>
765</div>
766
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]767 <p>Note that the two function types above are unique because the parameter has
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]768 a different attribute (sext in the first one, zext in the second). Also note
769 that the attribute for the function result (zext) comes immediately after the
770 argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]771
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]772 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]773 <dl>
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]774 <dt><tt>zext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]775 <dd>This indicates that the parameter should be zero extended just before
776 a call to this function.</dd>
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]777 <dt><tt>sext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]778 <dd>This indicates that the parameter should be sign extended just before
779 a call to this function.</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]780 <dt><tt>inreg</tt></dt>
781 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]782 possible) during assembling function call. Support for this attribute is
783 target-specific</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]784 <dt><tt>sret</tt></dt>
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]785 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]786 that is the return value of the function in the source program.</dd>
Reid Spencer9d1700e2007-03-22 02:18:56 +0000[diff] [blame]787 <dt><tt>noreturn</tt></dt>
788 <dd>This function attribute indicates that the function never returns. This
789 indicates to LLVM that every call to this function should be treated as if
790 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]791 <dt><tt>nounwind</tt></dt>
792 <dd>This function attribute indicates that the function type does not use
793 the unwind instruction and does not allow stack unwinding to propagate
794 through it.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]795 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]796
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]797</div>
798
799<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]800<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]801 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]802</div>
803
804<div class="doc_text">
805<p>
806Modules may contain "module-level inline asm" blocks, which corresponds to the
807GCC "file scope inline asm" blocks. These blocks are internally concatenated by
808LLVM and treated as a single unit, but may be separated in the .ll file if
809desired. The syntax is very simple:
810</p>
811
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]812<div class="doc_code">
813<pre>
814module asm "inline asm code goes here"
815module asm "more can go here"
816</pre>
817</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]818
819<p>The strings can contain any character by escaping non-printable characters.
820 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
821 for the number.
822</p>
823
824<p>
825 The inline asm code is simply printed to the machine code .s file when
826 assembly code is generated.
827</p>
828</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]829
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]830<!-- ======================================================================= -->
831<div class="doc_subsection">
832 <a name="datalayout">Data Layout</a>
833</div>
834
835<div class="doc_text">
836<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]837data is to be laid out in memory. The syntax for the data layout is simply:</p>
838<pre> target datalayout = "<i>layout specification</i>"</pre>
839<p>The <i>layout specification</i> consists of a list of specifications
840separated by the minus sign character ('-'). Each specification starts with a
841letter and may include other information after the letter to define some
842aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]843<dl>
844 <dt><tt>E</tt></dt>
845 <dd>Specifies that the target lays out data in big-endian form. That is, the
846 bits with the most significance have the lowest address location.</dd>
847 <dt><tt>e</tt></dt>
848 <dd>Specifies that hte target lays out data in little-endian form. That is,
849 the bits with the least significance have the lowest address location.</dd>
850 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
851 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
852 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
853 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
854 too.</dd>
855 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
856 <dd>This specifies the alignment for an integer type of a given bit
857 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
858 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
859 <dd>This specifies the alignment for a vector type of a given bit
860 <i>size</i>.</dd>
861 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
862 <dd>This specifies the alignment for a floating point type of a given bit
863 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
864 (double).</dd>
865 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
866 <dd>This specifies the alignment for an aggregate type of a given bit
867 <i>size</i>.</dd>
868</dl>
869<p>When constructing the data layout for a given target, LLVM starts with a
870default set of specifications which are then (possibly) overriden by the
871specifications in the <tt>datalayout</tt> keyword. The default specifications
872are given in this list:</p>
873<ul>
874 <li><tt>E</tt> - big endian</li>
875 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
876 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
877 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
878 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
879 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
880 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
881 alignment of 64-bits</li>
882 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
883 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
884 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
885 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
886 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
887</ul>
888<p>When llvm is determining the alignment for a given type, it uses the
889following rules:
890<ol>
891 <li>If the type sought is an exact match for one of the specifications, that
892 specification is used.</li>
893 <li>If no match is found, and the type sought is an integer type, then the
894 smallest integer type that is larger than the bitwidth of the sought type is
895 used. If none of the specifications are larger than the bitwidth then the the
896 largest integer type is used. For example, given the default specifications
897 above, the i7 type will use the alignment of i8 (next largest) while both
898 i65 and i256 will use the alignment of i64 (largest specified).</li>
899 <li>If no match is found, and the type sought is a vector type, then the
900 largest vector type that is smaller than the sought vector type will be used
901 as a fall back. This happens because <128 x double> can be implemented in
902 terms of 64 <2 x double>, for example.</li>
903</ol>
904</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]905
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]906<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]907<div class="doc_section"> <a name="typesystem">Type System</a> </div>
908<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]909
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]910<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]911
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]912<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]913intermediate representation. Being typed enables a number of
914optimizations to be performed on the IR directly, without having to do
915extra analyses on the side before the transformation. A strong type
916system makes it easier to read the generated code and enables novel
917analyses and transformations that are not feasible to perform on normal
918three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]919
920</div>
921
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]922<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]923<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]924<div class="doc_text">
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]925<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]926system. The current set of primitive types is as follows:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]927
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]928<table class="layout">
929 <tr class="layout">
930 <td class="left">
931 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]932 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]933 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]934 <tr><td><tt><a name="t_void">void</a></tt></td><td>No value</td></tr>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]935 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]936 </tbody>
937 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]938 </td>
939 <td class="right">
940 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]941 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]942 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]943 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]944 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]945 </tbody>
946 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]947 </td>
948 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]949</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]950</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]951
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]952<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]953<div class="doc_subsubsection"> <a name="t_classifications">Type
954Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]955<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]956<p>These different primitive types fall into a few useful
957classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]958
959<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]960 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]961 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]962 <tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]963 <td><a name="t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]964 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]965 </tr>
966 <tr>
967 <td><a name="t_floating">floating point</a></td>
968 <td><tt>float, double</tt></td>
969 </tr>
970 <tr>
971 <td><a name="t_firstclass">first class</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]972 <td><tt>i1, ..., float, double, <br/>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]973 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]974 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]975 </tr>
976 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]977</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]978
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]979<p>The <a href="#t_firstclass">first class</a> types are perhaps the
980most important. Values of these types are the only ones which can be
981produced by instructions, passed as arguments, or used as operands to
982instructions. This means that all structures and arrays must be
983manipulated either by pointer or by component.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]984</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]985
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]986<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]987<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]988
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]989<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]990
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]991<p>The real power in LLVM comes from the derived types in the system.
992This is what allows a programmer to represent arrays, functions,
993pointers, and other useful types. Note that these derived types may be
994recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]995
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]996</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]997
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]998<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]999<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1000
1001<div class="doc_text">
1002
1003<h5>Overview:</h5>
1004<p>The integer type is a very simple derived type that simply specifies an
1005arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10062^23-1 (about 8 million) can be specified.</p>
1007
1008<h5>Syntax:</h5>
1009
1010<pre>
1011 iN
1012</pre>
1013
1014<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1015value.</p>
1016
1017<h5>Examples:</h5>
1018<table class="layout">
1019 <tr class="layout">
1020 <td class="left">
1021 <tt>i1</tt><br/>
1022 <tt>i4</tt><br/>
1023 <tt>i8</tt><br/>
1024 <tt>i16</tt><br/>
1025 <tt>i32</tt><br/>
1026 <tt>i42</tt><br/>
1027 <tt>i64</tt><br/>
1028 <tt>i1942652</tt><br/>
1029 </td>
1030 <td class="left">
1031 A boolean integer of 1 bit<br/>
1032 A nibble sized integer of 4 bits.<br/>
1033 A byte sized integer of 8 bits.<br/>
1034 A half word sized integer of 16 bits.<br/>
1035 A word sized integer of 32 bits.<br/>
1036 An integer whose bit width is the answer. <br/>
1037 A double word sized integer of 64 bits.<br/>
1038 A really big integer of over 1 million bits.<br/>
1039 </td>
1040 </tr>
1041</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1042</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1043
1044<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1045<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1046
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1047<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1048
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1049<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1050
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1051<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1052sequentially in memory. The array type requires a size (number of
1053elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1054
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1055<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1056
1057<pre>
1058 [&lt;# elements&gt; x &lt;elementtype&gt;]
1059</pre>
1060
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1061<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1062be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1063
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1064<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1065<table class="layout">
1066 <tr class="layout">
1067 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1068 <tt>[40 x i32 ]</tt><br/>
1069 <tt>[41 x i32 ]</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1070 <tt>[40 x i8]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1071 </td>
1072 <td class="left">
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1073 Array of 40 32-bit integer values.<br/>
1074 Array of 41 32-bit integer values.<br/>
1075 Array of 40 8-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1076 </td>
1077 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1078</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1079<p>Here are some examples of multidimensional arrays:</p>
1080<table class="layout">
1081 <tr class="layout">
1082 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1083 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1084 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1085 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1086 </td>
1087 <td class="left">
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1088 3x4 array of 32-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1089 12x10 array of single precision floating point values.<br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1090 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1091 </td>
1092 </tr>
1093</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1094
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1095<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1096length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1097LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1098As a special case, however, zero length arrays are recognized to be variable
1099length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1100type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1101
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1102</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1103
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1104<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1105<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1106<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1107<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1108<p>The function type can be thought of as a function signature. It
1109consists of a return type and a list of formal parameter types.
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1110Function types are usually used to build virtual function tables
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1111(which are structures of pointers to functions), for indirect function
1112calls, and when defining a function.</p>
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1113<p>
1114The return type of a function type cannot be an aggregate type.
1115</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1116<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1117<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1118<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]1119specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1120which indicates that the function takes a variable number of arguments.
1121Variable argument functions can access their arguments with the <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1122 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1123<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1124<table class="layout">
1125 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1126 <td class="left"><tt>i32 (i32)</tt></td>
1127 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1128 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1129 </tr><tr class="layout">
Reid Spencere6a338d2007-01-15 18:28:34 +0000[diff] [blame]1130 <td class="left"><tt>float&nbsp;(i16&nbsp;sext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1131 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1132 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1133 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1134 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1135 <tt>float</tt>.
1136 </td>
1137 </tr><tr class="layout">
1138 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1139 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1140 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1141 which returns an integer. This is the signature for <tt>printf</tt> in
1142 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1143 </td>
1144 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1145</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1146
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1147</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1148<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1149<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1150<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1151<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1152<p>The structure type is used to represent a collection of data members
1153together in memory. The packing of the field types is defined to match
1154the ABI of the underlying processor. The elements of a structure may
1155be any type that has a size.</p>
1156<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1157and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1158field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1159instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1160<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1161<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1162<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1163<table class="layout">
1164 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1165 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1166 <td class="left">A triple of three <tt>i32</tt> values</td>
1167 </tr><tr class="layout">
1168 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1169 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1170 second element is a <a href="#t_pointer">pointer</a> to a
1171 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1172 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1173 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1174</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1175</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1176
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1177<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1178<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1179</div>
1180<div class="doc_text">
1181<h5>Overview:</h5>
1182<p>The packed structure type is used to represent a collection of data members
1183together in memory. There is no padding between fields. Further, the alignment
1184of a packed structure is 1 byte. The elements of a packed structure may
1185be any type that has a size.</p>
1186<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1187and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1188field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1189instruction.</p>
1190<h5>Syntax:</h5>
1191<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1192<h5>Examples:</h5>
1193<table class="layout">
1194 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1195 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1196 <td class="left">A triple of three <tt>i32</tt> values</td>
1197 </tr><tr class="layout">
1198 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1199 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1200 second element is a <a href="#t_pointer">pointer</a> to a
1201 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1202 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1203 </tr>
1204</table>
1205</div>
1206
1207<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1208<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1209<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1210<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1211<p>As in many languages, the pointer type represents a pointer or
1212reference to another object, which must live in memory.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1213<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1214<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1215<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1216<table class="layout">
1217 <tr class="layout">
1218 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1219 <tt>[4x i32]*</tt><br/>
1220 <tt>i32 (i32 *) *</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1221 </td>
1222 <td class="left">
1223 A <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a> of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1224 four <tt>i32</tt> values<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1225 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1226 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1227 <tt>i32</tt>.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1228 </td>
1229 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1230</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1231</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1232
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1233<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1234<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1235<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1236
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1237<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1238
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1239<p>A vector type is a simple derived type that represents a vector
1240of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1241are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1242A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1243elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1244of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1245considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1246
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1247<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1248
1249<pre>
1250 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1251</pre>
1252
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1253<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1254be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1255
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1256<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1257
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1258<table class="layout">
1259 <tr class="layout">
1260 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1261 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1262 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1263 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1264 </td>
1265 <td class="left">
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1266 Vector of 4 32-bit integer values.<br/>
1267 Vector of 8 floating-point values.<br/>
1268 Vector of 2 64-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1269 </td>
1270 </tr>
1271</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1272</div>
1273
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1274<!-- _______________________________________________________________________ -->
1275<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1276<div class="doc_text">
1277
1278<h5>Overview:</h5>
1279
1280<p>Opaque types are used to represent unknown types in the system. This
1281corresponds (for example) to the C notion of a foward declared structure type.
1282In LLVM, opaque types can eventually be resolved to any type (not just a
1283structure type).</p>
1284
1285<h5>Syntax:</h5>
1286
1287<pre>
1288 opaque
1289</pre>
1290
1291<h5>Examples:</h5>
1292
1293<table class="layout">
1294 <tr class="layout">
1295 <td class="left">
1296 <tt>opaque</tt>
1297 </td>
1298 <td class="left">
1299 An opaque type.<br/>
1300 </td>
1301 </tr>
1302</table>
1303</div>
1304
1305
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1306<!-- *********************************************************************** -->
1307<div class="doc_section"> <a name="constants">Constants</a> </div>
1308<!-- *********************************************************************** -->
1309
1310<div class="doc_text">
1311
1312<p>LLVM has several different basic types of constants. This section describes
1313them all and their syntax.</p>
1314
1315</div>
1316
1317<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1318<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1319
1320<div class="doc_text">
1321
1322<dl>
1323 <dt><b>Boolean constants</b></dt>
1324
1325 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1326 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1327 </dd>
1328
1329 <dt><b>Integer constants</b></dt>
1330
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1331 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1332 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1333 integer types.
1334 </dd>
1335
1336 <dt><b>Floating point constants</b></dt>
1337
1338 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1339 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1340 notation (see below). Floating point constants must have a <a
1341 href="#t_floating">floating point</a> type. </dd>
1342
1343 <dt><b>Null pointer constants</b></dt>
1344
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1345 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1346 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1347
1348</dl>
1349
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1350<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1351of floating point constants. For example, the form '<tt>double
13520x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13534.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1354(and the only time that they are generated by the disassembler) is when a
1355floating point constant must be emitted but it cannot be represented as a
1356decimal floating point number. For example, NaN's, infinities, and other
1357special values are represented in their IEEE hexadecimal format so that
1358assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1359
1360</div>
1361
1362<!-- ======================================================================= -->
1363<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1364</div>
1365
1366<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1367<p>Aggregate constants arise from aggregation of simple constants
1368and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1369
1370<dl>
1371 <dt><b>Structure constants</b></dt>
1372
1373 <dd>Structure constants are represented with notation similar to structure
1374 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1375 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
1376 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]1377 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1378 types of elements must match those specified by the type.
1379 </dd>
1380
1381 <dt><b>Array constants</b></dt>
1382
1383 <dd>Array constants are represented with notation similar to array type
1384 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1385 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1386 constants must have <a href="#t_array">array type</a>, and the number and
1387 types of elements must match those specified by the type.
1388 </dd>
1389
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1390 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1391
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1392 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1393 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1394 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]1395 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1396 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1397 match those specified by the type.
1398 </dd>
1399
1400 <dt><b>Zero initialization</b></dt>
1401
1402 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1403 value to zero of <em>any</em> type, including scalar and aggregate types.
1404 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]1405 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1406 initializers.
1407 </dd>
1408</dl>
1409
1410</div>
1411
1412<!-- ======================================================================= -->
1413<div class="doc_subsection">
1414 <a name="globalconstants">Global Variable and Function Addresses</a>
1415</div>
1416
1417<div class="doc_text">
1418
1419<p>The addresses of <a href="#globalvars">global variables</a> and <a
1420href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1421constants. These constants are explicitly referenced when the <a
1422href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1423href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1424file:</p>
1425
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1426<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1427<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1428%X = global i32 17
1429%Y = global i32 42
1430%Z = global [2 x i32*] [ i32* %X, i32* %Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1431</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1432</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1433
1434</div>
1435
1436<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1437<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1438<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1439 <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]1440 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1441 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1442
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1443 <p>Undefined values indicate to the compiler that the program is well defined
1444 no matter what value is used, giving the compiler more freedom to optimize.
1445 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1446</div>
1447
1448<!-- ======================================================================= -->
1449<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1450</div>
1451
1452<div class="doc_text">
1453
1454<p>Constant expressions are used to allow expressions involving other constants
1455to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1456href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1457that does not have side effects (e.g. load and call are not supported). The
1458following is the syntax for constant expressions:</p>
1459
1460<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1461 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1462 <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]1463 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1464
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1465 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1466 <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]1467 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]1468
1469 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1470 <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]1471 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]1472
1473 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1474 <dd>Truncate a floating point constant to another floating point type. The
1475 size of CST must be larger than the size of TYPE. Both types must be
1476 floating point.</dd>
1477
1478 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1479 <dd>Floating point extend a constant to another type. The size of CST must be
1480 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1481
1482 <dt><b><tt>fp2uint ( CST to TYPE )</tt></b></dt>
1483 <dd>Convert a floating point constant to the corresponding unsigned integer
1484 constant. TYPE must be an integer type. CST must be floating point. If the
1485 value won't fit in the integer type, the results are undefined.</dd>
1486
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1487 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1488 <dd>Convert a floating point constant to the corresponding signed integer
1489 constant. TYPE must be an integer type. CST must be floating point. If the
1490 value won't fit in the integer type, the results are undefined.</dd>
1491
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1492 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1493 <dd>Convert an unsigned integer constant to the corresponding floating point
1494 constant. TYPE must be floating point. CST must be of integer type. If the
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]1495 value won't fit in the floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1496
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1497 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1498 <dd>Convert a signed integer constant to the corresponding floating point
1499 constant. TYPE must be floating point. CST must be of integer type. If the
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]1500 value won't fit in the floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1501
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1502 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1503 <dd>Convert a pointer typed constant to the corresponding integer constant
1504 TYPE must be an integer type. CST must be of pointer type. The CST value is
1505 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1506
1507 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1508 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1509 pointer type. CST must be of integer type. The CST value is zero extended,
1510 truncated, or unchanged to make it fit in a pointer size. This one is
1511 <i>really</i> dangerous!</dd>
1512
1513 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1514 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1515 identical (same number of bits). The conversion is done as if the CST value
1516 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]1517 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1518 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1519 pointers it is only valid to cast to another pointer type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1520 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1521
1522 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1523
1524 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1525 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1526 instruction, the index list may have zero or more indexes, which are required
1527 to make sense for the type of "CSTPTR".</dd>
1528
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1529 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1530
1531 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1532 constants.</dd>
1533
1534 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1535 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1536
1537 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1538 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1539
1540 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1541
1542 <dd>Perform the <a href="#i_extractelement">extractelement
1543 operation</a> on constants.
1544
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1545 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1546
1547 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1548 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1549
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1550
1551 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1552
1553 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1554 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1555
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1556 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1557
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1558 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1559 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1560 binary</a> operations. The constraints on operands are the same as those for
1561 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1562 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1563</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1564</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1565
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1566<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1567<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1568<!-- *********************************************************************** -->
1569
1570<!-- ======================================================================= -->
1571<div class="doc_subsection">
1572<a name="inlineasm">Inline Assembler Expressions</a>
1573</div>
1574
1575<div class="doc_text">
1576
1577<p>
1578LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1579Module-Level Inline Assembly</a>) through the use of a special value. This
1580value represents the inline assembler as a string (containing the instructions
1581to emit), a list of operand constraints (stored as a string), and a flag that
1582indicates whether or not the inline asm expression has side effects. An example
1583inline assembler expression is:
1584</p>
1585
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1586<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1587<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1588i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1589</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1590</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1591
1592<p>
1593Inline assembler expressions may <b>only</b> be used as the callee operand of
1594a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1595</p>
1596
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1597<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1598<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1599%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]1600</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1601</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1602
1603<p>
1604Inline asms with side effects not visible in the constraint list must be marked
1605as having side effects. This is done through the use of the
1606'<tt>sideeffect</tt>' keyword, like so:
1607</p>
1608
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1609<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1610<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1611call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1612</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1613</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1614
1615<p>TODO: The format of the asm and constraints string still need to be
1616documented here. Constraints on what can be done (e.g. duplication, moving, etc
1617need to be documented).
1618</p>
1619
1620</div>
1621
1622<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1623<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1624<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1625
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1626<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1627
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1628<p>The LLVM instruction set consists of several different
1629classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1630instructions</a>, <a href="#binaryops">binary instructions</a>,
1631<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1632 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1633instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1634
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1635</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1637<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1638<div class="doc_subsection"> <a name="terminators">Terminator
1639Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1640
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1641<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1642
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1643<p>As mentioned <a href="#functionstructure">previously</a>, every
1644basic block in a program ends with a "Terminator" instruction, which
1645indicates which block should be executed after the current block is
1646finished. These terminator instructions typically yield a '<tt>void</tt>'
1647value: they produce control flow, not values (the one exception being
1648the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1649<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1650 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1651instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1652the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1653 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1654 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1655
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1656</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1657
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1658<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1659<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1660Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1661<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1662<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1663<pre> 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]1664 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1665</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1666<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1667<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1668value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1669<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1670returns a value and then causes control flow, and one that just causes
1671control flow to occur.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1672<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1673<p>The '<tt>ret</tt>' instruction may return any '<a
1674 href="#t_firstclass">first class</a>' type. Notice that a function is
1675not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1676instruction inside of the function that returns a value that does not
1677match the return type of the function.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1678<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1679<p>When the '<tt>ret</tt>' instruction is executed, control flow
1680returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1681 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1682the instruction after the call. If the caller was an "<a
1683 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1684at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1685returns a value, that value shall set the call or invoke instruction's
1686return value.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1687<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1688<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1689 ret void <i>; Return from a void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1690</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1691</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1692<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1693<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1694<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1695<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1696<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]1697</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1698<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1699<p>The '<tt>br</tt>' instruction is used to cause control flow to
1700transfer to a different basic block in the current function. There are
1701two forms of this instruction, corresponding to a conditional branch
1702and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1703<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1704<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1705single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1706unconditional form of the '<tt>br</tt>' instruction takes a single
1707'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1708<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1709<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1710argument is evaluated. If the value is <tt>true</tt>, control flows
1711to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1712control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1713<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1714<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]1715 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]1716</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1717<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1718<div class="doc_subsubsection">
1719 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1720</div>
1721
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1722<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1723<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1724
1725<pre>
1726 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1727</pre>
1728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1729<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1730
1731<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1732several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1733instruction, allowing a branch to occur to one of many possible
1734destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1735
1736
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1737<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1738
1739<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1740comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1741an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1742table is not allowed to contain duplicate constant entries.</p>
1743
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1744<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1745
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1746<p>The <tt>switch</tt> instruction specifies a table of values and
1747destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1748table is searched for the given value. If the value is found, control flow is
1749transfered to the corresponding destination; otherwise, control flow is
1750transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1751
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1752<h5>Implementation:</h5>
1753
1754<p>Depending on properties of the target machine and the particular
1755<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1756ways. For example, it could be generated as a series of chained conditional
1757branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1758
1759<h5>Example:</h5>
1760
1761<pre>
1762 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1763 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1764 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1765
1766 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1767 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1768
1769 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1770 switch i32 %val, label %otherwise [ i32 0, label %onzero
1771 i32 1, label %onone
1772 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1773</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1774</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1775
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1776<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1777<div class="doc_subsubsection">
1778 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1779</div>
1780
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1781<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1782
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1783<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1784
1785<pre>
1786 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; %&lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]1787 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1788</pre>
1789
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]1790<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1791
1792<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1793function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1794'<tt>normal</tt>' label or the
1795'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1796"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1797"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1798href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1799continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1800
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1801<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1802
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1803<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1804
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1805<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1806 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]1807 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1808 convention</a> the call should use. If none is specified, the call defaults
1809 to using C calling conventions.
1810 </li>
1811 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1812 function value being invoked. In most cases, this is a direct function
1813 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1814 an arbitrary pointer to function value.
1815 </li>
1816
1817 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1818 function to be invoked. </li>
1819
1820 <li>'<tt>function args</tt>': argument list whose types match the function
1821 signature argument types. If the function signature indicates the function
1822 accepts a variable number of arguments, the extra arguments can be
1823 specified. </li>
1824
1825 <li>'<tt>normal label</tt>': the label reached when the called function
1826 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1827
1828 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1829 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1830
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1831</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1832
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1833<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1834
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1835<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1836href="#i_call">call</a></tt>' instruction in most regards. The primary
1837difference is that it establishes an association with a label, which is used by
1838the runtime library to unwind the stack.</p>
1839
1840<p>This instruction is used in languages with destructors to ensure that proper
1841cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1842exception. Additionally, this is important for implementation of
1843'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1844
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1845<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1846<pre>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1847 %retval = invoke i32 %Test(i32 15) to label %Continue
1848 unwind label %TestCleanup <i>; {i32}:retval set</i>
1849 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1850 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1851</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1852</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1853
1854
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1855<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1856
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1857<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1858Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1859
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1860<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1861
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1862<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1863<pre>
1864 unwind
1865</pre>
1866
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1867<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1868
1869<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1870at the first callee in the dynamic call stack which used an <a
1871href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1872primarily used to implement exception handling.</p>
1873
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1874<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1875
1876<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1877immediately halt. The dynamic call stack is then searched for the first <a
1878href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1879execution continues at the "exceptional" destination block specified by the
1880<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1881dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1882</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1883
1884<!-- _______________________________________________________________________ -->
1885
1886<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1887Instruction</a> </div>
1888
1889<div class="doc_text">
1890
1891<h5>Syntax:</h5>
1892<pre>
1893 unreachable
1894</pre>
1895
1896<h5>Overview:</h5>
1897
1898<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1899instruction is used to inform the optimizer that a particular portion of the
1900code is not reachable. This can be used to indicate that the code after a
1901no-return function cannot be reached, and other facts.</p>
1902
1903<h5>Semantics:</h5>
1904
1905<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1906</div>
1907
1908
1909
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1910<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1911<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1912<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1913<p>Binary operators are used to do most of the computation in a
1914program. They require two operands, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1915produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1916multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1917The result value of a binary operator is not
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1918necessarily the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1919<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1920</div>
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_add">'<tt>add</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>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1926<pre> &lt;result&gt; = add &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1927</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1928<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1929<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1930<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1931<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1932 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1933 This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1934Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1935<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1936<p>The value produced is the integer or floating point sum of the two
1937operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1938<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1939<pre> &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1940</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1941</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1942<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1943<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1944Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1945<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1946<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1947<pre> &lt;result&gt; = sub &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1948</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1949<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1950<p>The '<tt>sub</tt>' instruction returns the difference of its two
1951operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1952<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
1953instruction present in most other intermediate representations.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1954<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1955<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1956 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1957values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1958This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1959Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1960<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1961<p>The value produced is the integer or floating point difference of
1962the two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1963<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame^]1964<pre>
1965 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1966 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1967</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1968</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1969<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1970<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
1971Instruction</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>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1974<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</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>mul</tt>' instruction returns the product of its two
1978operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1979<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1980<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1981 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1982values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1983This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1984Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1986<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1987two operands.</p>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1988<p>Because the operands are the same width, the result of an integer
1989multiplication is the same whether the operands should be deemed unsigned or
1990signed.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1991<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1992<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]1993</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1994</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1995<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]1996<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
1997</a></div>
1998<div class="doc_text">
1999<h5>Syntax:</h5>
2000<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2001</pre>
2002<h5>Overview:</h5>
2003<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2004operands.</p>
2005<h5>Arguments:</h5>
2006<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2007<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2008types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2009of the values in which case the elements must be integers.</p>
2010<h5>Semantics:</h5>
2011<p>The value produced is the unsigned integer quotient of the two operands. This
2012instruction always performs an unsigned division operation, regardless of
2013whether the arguments are unsigned or not.</p>
2014<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2015<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]2016</pre>
2017</div>
2018<!-- _______________________________________________________________________ -->
2019<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2020</a> </div>
2021<div class="doc_text">
2022<h5>Syntax:</h5>
2023<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2024</pre>
2025<h5>Overview:</h5>
2026<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2027operands.</p>
2028<h5>Arguments:</h5>
2029<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2030<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2031types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2032of the values in which case the elements must be integers.</p>
2033<h5>Semantics:</h5>
2034<p>The value produced is the signed integer quotient of the two operands. This
2035instruction always performs a signed division operation, regardless of whether
2036the arguments are signed or not.</p>
2037<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2038<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]2039</pre>
2040</div>
2041<!-- _______________________________________________________________________ -->
2042<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2043Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2044<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Syntax:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2046<pre> &lt;result&gt; = fdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2047</pre>
2048<h5>Overview:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2049<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2050operands.</p>
2051<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2052<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2053<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2054identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2055versions of floating point values.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2056<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2057<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2058<h5>Example:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2059<pre> &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]2060</pre>
2061</div>
2062<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2063<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2064</div>
2065<div class="doc_text">
2066<h5>Syntax:</h5>
2067<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2068</pre>
2069<h5>Overview:</h5>
2070<p>The '<tt>urem</tt>' instruction returns the remainder from the
2071unsigned division of its two arguments.</p>
2072<h5>Arguments:</h5>
2073<p>The two arguments to the '<tt>urem</tt>' instruction must be
2074<a href="#t_integer">integer</a> values. Both arguments must have identical
2075types.</p>
2076<h5>Semantics:</h5>
2077<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2078This instruction always performs an unsigned division to get the remainder,
2079regardless of whether the arguments are unsigned or not.</p>
2080<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2081<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]2082</pre>
2083
2084</div>
2085<!-- _______________________________________________________________________ -->
2086<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2087Instruction</a> </div>
2088<div class="doc_text">
2089<h5>Syntax:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2090<pre> &lt;result&gt; = srem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2091</pre>
2092<h5>Overview:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2093<p>The '<tt>srem</tt>' instruction returns the remainder from the
2094signed division of its two operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2095<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2096<p>The two arguments to the '<tt>srem</tt>' instruction must be
2097<a href="#t_integer">integer</a> values. Both arguments must have identical
2098types.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2099<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2100<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2101has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2102operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2103a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2104 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2105Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2106please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2107Wikipedia: modulo operation</a>.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2108<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2109<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]2110</pre>
2111
2112</div>
2113<!-- _______________________________________________________________________ -->
2114<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2115Instruction</a> </div>
2116<div class="doc_text">
2117<h5>Syntax:</h5>
2118<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2119</pre>
2120<h5>Overview:</h5>
2121<p>The '<tt>frem</tt>' instruction returns the remainder from the
2122division of its two operands.</p>
2123<h5>Arguments:</h5>
2124<p>The two arguments to the '<tt>frem</tt>' instruction must be
2125<a href="#t_floating">floating point</a> values. Both arguments must have
2126identical types.</p>
2127<h5>Semantics:</h5>
2128<p>This instruction returns the <i>remainder</i> of a division.</p>
2129<h5>Example:</h5>
2130<pre> &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]2131</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2132</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2133
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2134<!-- ======================================================================= -->
2135<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2136Operations</a> </div>
2137<div class="doc_text">
2138<p>Bitwise binary operators are used to do various forms of
2139bit-twiddling in a program. They are generally very efficient
2140instructions and can commonly be strength reduced from other
2141instructions. They require two operands, execute an operation on them,
2142and produce a single value. The resulting value of the bitwise binary
2143operators is always the same type as its first operand.</p>
2144</div>
2145
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2146<!-- _______________________________________________________________________ -->
2147<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2148Instruction</a> </div>
2149<div class="doc_text">
2150<h5>Syntax:</h5>
2151<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2152</pre>
2153<h5>Overview:</h5>
2154<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2155the left a specified number of bits.</p>
2156<h5>Arguments:</h5>
2157<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2158 href="#t_integer">integer</a> type.</p>
2159<h5>Semantics:</h5>
2160<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>.</p>
2161<h5>Example:</h5><pre>
2162 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2163 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2164 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
2165</pre>
2166</div>
2167<!-- _______________________________________________________________________ -->
2168<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2169Instruction</a> </div>
2170<div class="doc_text">
2171<h5>Syntax:</h5>
2172<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2173</pre>
2174
2175<h5>Overview:</h5>
2176<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2177operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2178
2179<h5>Arguments:</h5>
2180<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2181<a href="#t_integer">integer</a> type.</p>
2182
2183<h5>Semantics:</h5>
2184<p>This instruction always performs a logical shift right operation. The most
2185significant bits of the result will be filled with zero bits after the
2186shift.</p>
2187
2188<h5>Example:</h5>
2189<pre>
2190 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2191 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2192 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2193 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
2194</pre>
2195</div>
2196
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2197<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2198<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2199Instruction</a> </div>
2200<div class="doc_text">
2201
2202<h5>Syntax:</h5>
2203<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2204</pre>
2205
2206<h5>Overview:</h5>
2207<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2208operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2209
2210<h5>Arguments:</h5>
2211<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2212<a href="#t_integer">integer</a> type.</p>
2213
2214<h5>Semantics:</h5>
2215<p>This instruction always performs an arithmetic shift right operation,
2216The most significant bits of the result will be filled with the sign bit
2217of <tt>var1</tt>.</p>
2218
2219<h5>Example:</h5>
2220<pre>
2221 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2222 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2223 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2224 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
2225</pre>
2226</div>
2227
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2228<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2229<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2230Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2231<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2232<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2233<pre> &lt;result&gt; = and &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2234</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2235<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2236<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2237its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2238<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2239<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2240 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2241identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2242<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2243<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2244<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2245<div style="align: center">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2246<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2247 <tbody>
2248 <tr>
2249 <td>In0</td>
2250 <td>In1</td>
2251 <td>Out</td>
2252 </tr>
2253 <tr>
2254 <td>0</td>
2255 <td>0</td>
2256 <td>0</td>
2257 </tr>
2258 <tr>
2259 <td>0</td>
2260 <td>1</td>
2261 <td>0</td>
2262 </tr>
2263 <tr>
2264 <td>1</td>
2265 <td>0</td>
2266 <td>0</td>
2267 </tr>
2268 <tr>
2269 <td>1</td>
2270 <td>1</td>
2271 <td>1</td>
2272 </tr>
2273 </tbody>
2274</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2275</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2276<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2277<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2278 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2279 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2280</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2281</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2282<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2283<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2284<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2285<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2286<pre> &lt;result&gt; = or &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2287</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2288<h5>Overview:</h5>
2289<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2290or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2291<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2292<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2293 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2294identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2295<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2296<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2297<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2298<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2299<table border="1" cellspacing="0" cellpadding="4">
2300 <tbody>
2301 <tr>
2302 <td>In0</td>
2303 <td>In1</td>
2304 <td>Out</td>
2305 </tr>
2306 <tr>
2307 <td>0</td>
2308 <td>0</td>
2309 <td>0</td>
2310 </tr>
2311 <tr>
2312 <td>0</td>
2313 <td>1</td>
2314 <td>1</td>
2315 </tr>
2316 <tr>
2317 <td>1</td>
2318 <td>0</td>
2319 <td>1</td>
2320 </tr>
2321 <tr>
2322 <td>1</td>
2323 <td>1</td>
2324 <td>1</td>
2325 </tr>
2326 </tbody>
2327</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2328</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2329<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2330<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2331 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2332 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</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 Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2335<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2336<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2337Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2338<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2339<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2340<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2341</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2342<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2343<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2344or of its two operands. The <tt>xor</tt> is used to implement the
2345"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2346<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2347<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2348 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2349identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2350<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2351<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2352<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2353<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2354<table border="1" cellspacing="0" cellpadding="4">
2355 <tbody>
2356 <tr>
2357 <td>In0</td>
2358 <td>In1</td>
2359 <td>Out</td>
2360 </tr>
2361 <tr>
2362 <td>0</td>
2363 <td>0</td>
2364 <td>0</td>
2365 </tr>
2366 <tr>
2367 <td>0</td>
2368 <td>1</td>
2369 <td>1</td>
2370 </tr>
2371 <tr>
2372 <td>1</td>
2373 <td>0</td>
2374 <td>1</td>
2375 </tr>
2376 <tr>
2377 <td>1</td>
2378 <td>1</td>
2379 <td>0</td>
2380 </tr>
2381 </tbody>
2382</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2383</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2384<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2385<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2386<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2387 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2388 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2389 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2390</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2391</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2393<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2394<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2395 <a name="vectorops">Vector Operations</a>
2396</div>
2397
2398<div class="doc_text">
2399
2400<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2401target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2402vector-specific operations needed to process vectors effectively. While LLVM
2403does directly support these vector operations, many sophisticated algorithms
2404will want to use target-specific intrinsics to take full advantage of a specific
2405target.</p>
2406
2407</div>
2408
2409<!-- _______________________________________________________________________ -->
2410<div class="doc_subsubsection">
2411 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2412</div>
2413
2414<div class="doc_text">
2415
2416<h5>Syntax:</h5>
2417
2418<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2419 &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]2420</pre>
2421
2422<h5>Overview:</h5>
2423
2424<p>
2425The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2426element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2427</p>
2428
2429
2430<h5>Arguments:</h5>
2431
2432<p>
2433The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2434value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2435an index indicating the position from which to extract the element.
2436The index may be a variable.</p>
2437
2438<h5>Semantics:</h5>
2439
2440<p>
2441The result is a scalar of the same type as the element type of
2442<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2443<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2444results are undefined.
2445</p>
2446
2447<h5>Example:</h5>
2448
2449<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2450 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2451</pre>
2452</div>
2453
2454
2455<!-- _______________________________________________________________________ -->
2456<div class="doc_subsubsection">
2457 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2458</div>
2459
2460<div class="doc_text">
2461
2462<h5>Syntax:</h5>
2463
2464<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2465 &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]2466</pre>
2467
2468<h5>Overview:</h5>
2469
2470<p>
2471The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2472element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2473</p>
2474
2475
2476<h5>Arguments:</h5>
2477
2478<p>
2479The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2480value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2481scalar value whose type must equal the element type of the first
2482operand. The third operand is an index indicating the position at
2483which to insert the value. The index may be a variable.</p>
2484
2485<h5>Semantics:</h5>
2486
2487<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2488The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2489element values are those of <tt>val</tt> except at position
2490<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2491exceeds the length of <tt>val</tt>, the results are undefined.
2492</p>
2493
2494<h5>Example:</h5>
2495
2496<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2497 %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]2498</pre>
2499</div>
2500
2501<!-- _______________________________________________________________________ -->
2502<div class="doc_subsubsection">
2503 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2504</div>
2505
2506<div class="doc_text">
2507
2508<h5>Syntax:</h5>
2509
2510<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2511 &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]2512</pre>
2513
2514<h5>Overview:</h5>
2515
2516<p>
2517The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2518from two input vectors, returning a vector of the same type.
2519</p>
2520
2521<h5>Arguments:</h5>
2522
2523<p>
2524The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2525with types that match each other and types that match the result of the
2526instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2527of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2528</p>
2529
2530<p>
2531The shuffle mask operand is required to be a constant vector with either
2532constant integer or undef values.
2533</p>
2534
2535<h5>Semantics:</h5>
2536
2537<p>
2538The elements of the two input vectors are numbered from left to right across
2539both of the vectors. The shuffle mask operand specifies, for each element of
2540the result vector, which element of the two input registers the result element
2541gets. The element selector may be undef (meaning "don't care") and the second
2542operand may be undef if performing a shuffle from only one vector.
2543</p>
2544
2545<h5>Example:</h5>
2546
2547<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2548 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2549 &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]2550 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2551 &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]2552</pre>
2553</div>
2554
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2555
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2556<!-- ======================================================================= -->
2557<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2558 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2559</div>
2560
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2561<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2562
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2563<p>A key design point of an SSA-based representation is how it
2564represents memory. In LLVM, no memory locations are in SSA form, which
2565makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2566allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2567
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2568</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2569
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2570<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2571<div class="doc_subsubsection">
2572 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2573</div>
2574
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2575<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2576
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2577<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2578
2579<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2580 &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]2581</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2582
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2583<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2584
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2585<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2586heap and returns a pointer to it.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2587
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2588<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2589
2590<p>The '<tt>malloc</tt>' instruction allocates
2591<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]2592bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2593appropriate type to the program. If "NumElements" is specified, it is the
2594number of elements allocated. If an alignment is specified, the value result
2595of the allocation is guaranteed to be aligned to at least that boundary. If
2596not specified, or if zero, the target can choose to align the allocation on any
2597convenient boundary.</p>
2598
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2599<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2600
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2601<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2602
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2603<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2604a pointer is returned.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2605
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2606<h5>Example:</h5>
2607
2608<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2609 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2610
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame^]2611 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2612 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2613 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2614 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2615 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2616</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2617</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2618
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2619<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2620<div class="doc_subsubsection">
2621 <a name="i_free">'<tt>free</tt>' Instruction</a>
2622</div>
2623
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2624<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2625
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2626<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2627
2628<pre>
2629 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2630</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2631
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2632<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2633
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2634<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2635memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2637<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2638
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2639<p>'<tt>value</tt>' shall be a pointer value that points to a value
2640that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2641instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2642
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2643<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2644
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2645<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2646after this instruction executes.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2647
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2648<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2649
2650<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2651 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2652 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2653</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2654</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2655
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2656<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2657<div class="doc_subsubsection">
2658 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2659</div>
2660
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2661<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2662
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2663<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2664
2665<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2666 &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]2667</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2668
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2669<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2670
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2671<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2672currently executing function, to be automatically released when this function
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2673returns to its caller.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2675<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2676
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2677<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2678bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2679appropriate type to the program. If "NumElements" is specified, it is the
2680number of elements allocated. If an alignment is specified, the value result
2681of the allocation is guaranteed to be aligned to at least that boundary. If
2682not specified, or if zero, the target can choose to align the allocation on any
2683convenient boundary.</p>
2684
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2685<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2686
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2687<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2688
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2689<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2690memory is automatically released when the function returns. The '<tt>alloca</tt>'
2691instruction is commonly used to represent automatic variables that must
2692have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]2693 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2694instructions), the memory is reclaimed.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2696<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2697
2698<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2699 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2700 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2701 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2702 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2703</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2704</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2705
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2706<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2707<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2708Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2709<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2710<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2711<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]2712<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2713<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2714<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2715<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2716address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]2717 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2718marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2719the number or order of execution of this <tt>load</tt> with other
2720volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2721instructions. </p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2722<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2723<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2724<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2725<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2726 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2727 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2728 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2729</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2730</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2731<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2732<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2733Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]2734<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2735<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2736<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2737 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]2738</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2739<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2740<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2741<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2742<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2743to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2744operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2745operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2746optimizer is not allowed to modify the number or order of execution of
2747this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2748 href="#i_store">store</a></tt> instructions.</p>
2749<h5>Semantics:</h5>
2750<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2751at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2752<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2753<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2754 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2755 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2756 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2757</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2758</div>
2759
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2760<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2761<div class="doc_subsubsection">
2762 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2763</div>
2764
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2765<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2766<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2767<pre>
2768 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2769</pre>
2770
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2771<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2772
2773<p>
2774The '<tt>getelementptr</tt>' instruction is used to get the address of a
2775subelement of an aggregate data structure.</p>
2776
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2777<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2778
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2779<p>This instruction takes a list of integer operands that indicate what
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2780elements of the aggregate object to index to. The actual types of the arguments
2781provided depend on the type of the first pointer argument. The
2782'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]2783levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2784structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2785into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2786be sign extended to 64-bit values.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2787
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2788<p>For example, let's consider a C code fragment and how it gets
2789compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2790
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2791<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2792<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2793struct RT {
2794 char A;
2795 i32 B[10][20];
2796 char C;
2797};
2798struct ST {
2799 i32 X;
2800 double Y;
2801 struct RT Z;
2802};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2803
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2804i32 *foo(struct ST *s) {
2805 return &amp;s[1].Z.B[5][13];
2806}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2807</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2808</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2809
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2810<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2811
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2812<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2813<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2814%RT = type { i8 , [10 x [20 x i32]], i8 }
2815%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2816
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2817define i32* %foo(%ST* %s) {
2818entry:
2819 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2820 ret i32* %reg
2821}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2822</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2823</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2824
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2825<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2826
2827<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2828on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2829and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]2830<a href="#t_integer">integer</a> type but the value will always be sign extended
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2831to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]2832<b>constants</b>.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2833
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2834<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]2835type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2836}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2837the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2838i8 }</tt>' type, another structure. The third index indexes into the second
2839element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2840array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2841'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2842to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2843
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2844<p>Note that it is perfectly legal to index partially through a
2845structure, returning a pointer to an inner element. Because of this,
2846the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2847
2848<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2849 define i32* %foo(%ST* %s) {
2850 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2851 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2852 %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]2853 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2854 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2855 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2856 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2857</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2858
2859<p>Note that it is undefined to access an array out of bounds: array and
2860pointer indexes must always be within the defined bounds of the array type.
2861The one exception for this rules is zero length arrays. These arrays are
2862defined to be accessible as variable length arrays, which requires access
2863beyond the zero'th element.</p>
2864
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2865<p>The getelementptr instruction is often confusing. For some more insight
2866into how it works, see <a href="GetElementPtr.html">the getelementptr
2867FAQ</a>.</p>
2868
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2869<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2870
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2871<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2872 <i>; yields [12 x i8]*:aptr</i>
2873 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2874</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2875</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2876
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2877<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2878<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2879</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2880<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2881<p>The instructions in this category are the conversion instructions (casting)
2882which all take a single operand and a type. They perform various bit conversions
2883on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2884</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2885
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2886<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2887<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2888 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2889</div>
2890<div class="doc_text">
2891
2892<h5>Syntax:</h5>
2893<pre>
2894 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2895</pre>
2896
2897<h5>Overview:</h5>
2898<p>
2899The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2900</p>
2901
2902<h5>Arguments:</h5>
2903<p>
2904The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2905be 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]2906and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2907type. The bit size of <tt>value</tt> must be larger than the bit size of
2908<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2909
2910<h5>Semantics:</h5>
2911<p>
2912The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2913and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2914larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2915It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2916
2917<h5>Example:</h5>
2918<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2919 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2920 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2921 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2922</pre>
2923</div>
2924
2925<!-- _______________________________________________________________________ -->
2926<div class="doc_subsubsection">
2927 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
2928</div>
2929<div class="doc_text">
2930
2931<h5>Syntax:</h5>
2932<pre>
2933 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2934</pre>
2935
2936<h5>Overview:</h5>
2937<p>The '<tt>zext</tt>' instruction zero extends its operand to type
2938<tt>ty2</tt>.</p>
2939
2940
2941<h5>Arguments:</h5>
2942<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]2943<a href="#t_integer">integer</a> type, and a type to cast it to, which must
2944also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2945<tt>value</tt> must be smaller than the bit size of the destination type,
2946<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2947
2948<h5>Semantics:</h5>
2949<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]2950bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2951
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]2952<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]2953
2954<h5>Example:</h5>
2955<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2956 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2957 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2958</pre>
2959</div>
2960
2961<!-- _______________________________________________________________________ -->
2962<div class="doc_subsubsection">
2963 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
2964</div>
2965<div class="doc_text">
2966
2967<h5>Syntax:</h5>
2968<pre>
2969 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2970</pre>
2971
2972<h5>Overview:</h5>
2973<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
2974
2975<h5>Arguments:</h5>
2976<p>
2977The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2978<a href="#t_integer">integer</a> type, and a type to cast it to, which must
2979also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2980<tt>value</tt> must be smaller than the bit size of the destination type,
2981<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2982
2983<h5>Semantics:</h5>
2984<p>
2985The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
2986bit (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]2987the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2988
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2989<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]2990
2991<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2992<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2993 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2994 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2995</pre>
2996</div>
2997
2998<!-- _______________________________________________________________________ -->
2999<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3000 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3001</div>
3002
3003<div class="doc_text">
3004
3005<h5>Syntax:</h5>
3006
3007<pre>
3008 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3009</pre>
3010
3011<h5>Overview:</h5>
3012<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3013<tt>ty2</tt>.</p>
3014
3015
3016<h5>Arguments:</h5>
3017<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3018 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3019cast it to. The size of <tt>value</tt> must be larger than the size of
3020<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3021<i>no-op cast</i>.</p>
3022
3023<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3024<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3025<a href="#t_floating">floating point</a> type to a smaller
3026<a href="#t_floating">floating point</a> type. If the value cannot fit within
3027the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3028
3029<h5>Example:</h5>
3030<pre>
3031 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3032 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3033</pre>
3034</div>
3035
3036<!-- _______________________________________________________________________ -->
3037<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3038 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3039</div>
3040<div class="doc_text">
3041
3042<h5>Syntax:</h5>
3043<pre>
3044 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3045</pre>
3046
3047<h5>Overview:</h5>
3048<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3049floating point value.</p>
3050
3051<h5>Arguments:</h5>
3052<p>The '<tt>fpext</tt>' instruction takes a
3053<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3054and a <a href="#t_floating">floating point</a> type to cast it to. The source
3055type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3056
3057<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3058<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3059<a href="#t_floating">floating point</a> type to a larger
3060<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3061used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3062<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]3063
3064<h5>Example:</h5>
3065<pre>
3066 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3067 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3068</pre>
3069</div>
3070
3071<!-- _______________________________________________________________________ -->
3072<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3073 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3074</div>
3075<div class="doc_text">
3076
3077<h5>Syntax:</h5>
3078<pre>
3079 &lt;result&gt; = fp2uint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3080</pre>
3081
3082<h5>Overview:</h5>
3083<p>The '<tt>fp2uint</tt>' converts a floating point <tt>value</tt> to its
3084unsigned integer equivalent of type <tt>ty2</tt>.
3085</p>
3086
3087<h5>Arguments:</h5>
3088<p>The '<tt>fp2uint</tt>' instruction takes a value to cast, which must be a
3089<a href="#t_floating">floating point</a> value, and a type to cast it to, which
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3090must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3091
3092<h5>Semantics:</h5>
3093<p> The '<tt>fp2uint</tt>' instruction converts its
3094<a href="#t_floating">floating point</a> operand into the nearest (rounding
3095towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3096the results are undefined.</p>
3097
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3098<p>When converting to i1, the conversion is done as a comparison against
3099zero. If the <tt>value</tt> was zero, the i1 result will be <tt>false</tt>.
3100If the <tt>value</tt> was non-zero, the i1 result will be <tt>true</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3101
3102<h5>Example:</h5>
3103<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3104 %X = fp2uint double 123.0 to i32 <i>; yields i32:123</i>
3105 %Y = fp2uint float 1.0E+300 to i1 <i>; yields i1:true</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3106 %X = fp2uint float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3107</pre>
3108</div>
3109
3110<!-- _______________________________________________________________________ -->
3111<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3112 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3113</div>
3114<div class="doc_text">
3115
3116<h5>Syntax:</h5>
3117<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3118 &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]3119</pre>
3120
3121<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3122<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3123<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]3124</p>
3125
3126
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3127<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3128<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3129<a href="#t_floating">floating point</a> value, and a type to cast it to, which
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3130must also be an <a href="#t_integer">integer</a> type.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3131
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3132<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3133<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3134<a href="#t_floating">floating point</a> operand into the nearest (rounding
3135towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3136the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3137
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3138<p>When converting to i1, the conversion is done as a comparison against
3139zero. If the <tt>value</tt> was zero, the i1 result will be <tt>false</tt>.
3140If the <tt>value</tt> was non-zero, the i1 result will be <tt>true</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3141
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3142<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3143<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3144 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
3145 %Y = fptosi float 1.0E-247 to i1 <i>; yields i1:true</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3146 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3147</pre>
3148</div>
3149
3150<!-- _______________________________________________________________________ -->
3151<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3152 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3153</div>
3154<div class="doc_text">
3155
3156<h5>Syntax:</h5>
3157<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3158 &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]3159</pre>
3160
3161<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3162<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3163integer and converts that value to the <tt>ty2</tt> type.</p>
3164
3165
3166<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3167<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be an
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3168<a href="#t_integer">integer</a> value, and a type to cast it to, which must
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3169be a <a href="#t_floating">floating point</a> type.</p>
3170
3171<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3172<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3173integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3174the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3175
3176
3177<h5>Example:</h5>
3178<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3179 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3180 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3181</pre>
3182</div>
3183
3184<!-- _______________________________________________________________________ -->
3185<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3186 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3187</div>
3188<div class="doc_text">
3189
3190<h5>Syntax:</h5>
3191<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3192 &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]3193</pre>
3194
3195<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3196<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3197integer and converts that value to the <tt>ty2</tt> type.</p>
3198
3199<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3200<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be an
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3201<a href="#t_integer">integer</a> value, and a type to cast it to, which must be
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3202a <a href="#t_floating">floating point</a> type.</p>
3203
3204<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3205<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3206integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3207the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3208
3209<h5>Example:</h5>
3210<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3211 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3212 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3213</pre>
3214</div>
3215
3216<!-- _______________________________________________________________________ -->
3217<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3218 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3219</div>
3220<div class="doc_text">
3221
3222<h5>Syntax:</h5>
3223<pre>
3224 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3225</pre>
3226
3227<h5>Overview:</h5>
3228<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3229the integer type <tt>ty2</tt>.</p>
3230
3231<h5>Arguments:</h5>
3232<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3233must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3234<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3235
3236<h5>Semantics:</h5>
3237<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3238<tt>ty2</tt> by interpreting the pointer value as an integer and either
3239truncating or zero extending that value to the size of the integer type. If
3240<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3241<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]3242are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3243change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3244
3245<h5>Example:</h5>
3246<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3247 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3248 %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]3249</pre>
3250</div>
3251
3252<!-- _______________________________________________________________________ -->
3253<div class="doc_subsubsection">
3254 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3255</div>
3256<div class="doc_text">
3257
3258<h5>Syntax:</h5>
3259<pre>
3260 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3261</pre>
3262
3263<h5>Overview:</h5>
3264<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3265a pointer type, <tt>ty2</tt>.</p>
3266
3267<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3268<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3269value to cast, and a type to cast it to, which must be a
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]3270<a href="#t_pointer">pointer</a> type.
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3271
3272<h5>Semantics:</h5>
3273<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3274<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3275the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3276size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3277the size of a pointer then a zero extension is done. If they are the same size,
3278nothing is done (<i>no-op cast</i>).</p>
3279
3280<h5>Example:</h5>
3281<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3282 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3283 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3284 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3285</pre>
3286</div>
3287
3288<!-- _______________________________________________________________________ -->
3289<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3290 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3291</div>
3292<div class="doc_text">
3293
3294<h5>Syntax:</h5>
3295<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3296 &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]3297</pre>
3298
3299<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3300<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3301<tt>ty2</tt> without changing any bits.</p>
3302
3303<h5>Arguments:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3304<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3305a first class value, and a type to cast it to, which must also be a <a
3306 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3307and the destination type, <tt>ty2</tt>, must be identical. If the source
3308type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3309
3310<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3311<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3312<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3313this conversion. The conversion is done as if the <tt>value</tt> had been
3314stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3315converted to other pointer types with this instruction. To convert pointers to
3316other types, use the <a href="#i_inttoptr">inttoptr</a> or
3317<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3318
3319<h5>Example:</h5>
3320<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3321 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3322 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3323 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3324</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3325</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3326
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3327<!-- ======================================================================= -->
3328<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3329<div class="doc_text">
3330<p>The instructions in this category are the "miscellaneous"
3331instructions, which defy better classification.</p>
3332</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3333
3334<!-- _______________________________________________________________________ -->
3335<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3336</div>
3337<div class="doc_text">
3338<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3339<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3340</pre>
3341<h5>Overview:</h5>
3342<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3343of its two integer operands.</p>
3344<h5>Arguments:</h5>
3345<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3346the condition code indicating the kind of comparison to perform. It is not
3347a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3348<ol>
3349 <li><tt>eq</tt>: equal</li>
3350 <li><tt>ne</tt>: not equal </li>
3351 <li><tt>ugt</tt>: unsigned greater than</li>
3352 <li><tt>uge</tt>: unsigned greater or equal</li>
3353 <li><tt>ult</tt>: unsigned less than</li>
3354 <li><tt>ule</tt>: unsigned less or equal</li>
3355 <li><tt>sgt</tt>: signed greater than</li>
3356 <li><tt>sge</tt>: signed greater or equal</li>
3357 <li><tt>slt</tt>: signed less than</li>
3358 <li><tt>sle</tt>: signed less or equal</li>
3359</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3360<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3361<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3362<h5>Semantics:</h5>
3363<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3364the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3365yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3366<ol>
3367 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3368 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3369 </li>
3370 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3371 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3372 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3373 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3374 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3375 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3376 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3377 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3378 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3379 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3380 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3381 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3382 <li><tt>sge</tt>: interprets the operands as signed values and yields
3383 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3384 <li><tt>slt</tt>: interprets the operands as signed values and yields
3385 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3386 <li><tt>sle</tt>: interprets the operands as signed values and yields
3387 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3388</ol>
3389<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3390values are compared as if they were integers.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3391
3392<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3393<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3394 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3395 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3396 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3397 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3398 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3399</pre>
3400</div>
3401
3402<!-- _______________________________________________________________________ -->
3403<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3404</div>
3405<div class="doc_text">
3406<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3407<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3408</pre>
3409<h5>Overview:</h5>
3410<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3411of its floating point operands.</p>
3412<h5>Arguments:</h5>
3413<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3414the condition code indicating the kind of comparison to perform. It is not
3415a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3416<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3417 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3418 <li><tt>oeq</tt>: ordered and equal</li>
3419 <li><tt>ogt</tt>: ordered and greater than </li>
3420 <li><tt>oge</tt>: ordered and greater than or equal</li>
3421 <li><tt>olt</tt>: ordered and less than </li>
3422 <li><tt>ole</tt>: ordered and less than or equal</li>
3423 <li><tt>one</tt>: ordered and not equal</li>
3424 <li><tt>ord</tt>: ordered (no nans)</li>
3425 <li><tt>ueq</tt>: unordered or equal</li>
3426 <li><tt>ugt</tt>: unordered or greater than </li>
3427 <li><tt>uge</tt>: unordered or greater than or equal</li>
3428 <li><tt>ult</tt>: unordered or less than </li>
3429 <li><tt>ule</tt>: unordered or less than or equal</li>
3430 <li><tt>une</tt>: unordered or not equal</li>
3431 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3432 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3433</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3434<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]3435<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3436<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3437<a href="#t_floating">floating point</a> typed. They must have identical
3438types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3439<h5>Semantics:</h5>
3440<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3441the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3442yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3443<ol>
3444 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3445 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3446 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3447 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3448 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3449 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3450 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3451 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3452 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3453 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3454 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3455 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3456 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3457 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3458 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3459 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3460 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3461 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3462 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3463 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3464 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3465 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3466 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3467 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3468 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3469 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3470 <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]3471 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3472</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3473
3474<h5>Example:</h5>
3475<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3476 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3477 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3478 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3479</pre>
3480</div>
3481
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3482<!-- _______________________________________________________________________ -->
3483<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3484Instruction</a> </div>
3485<div class="doc_text">
3486<h5>Syntax:</h5>
3487<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3488<h5>Overview:</h5>
3489<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3490the SSA graph representing the function.</p>
3491<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3492<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3493field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3494as arguments, with one pair for each predecessor basic block of the
3495current block. Only values of <a href="#t_firstclass">first class</a>
3496type may be used as the value arguments to the PHI node. Only labels
3497may be used as the label arguments.</p>
3498<p>There must be no non-phi instructions between the start of a basic
3499block and the PHI instructions: i.e. PHI instructions must be first in
3500a basic block.</p>
3501<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3502<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3503specified by the pair corresponding to the predecessor basic block that executed
3504just prior to the current block.</p>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3505<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3506<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3507</div>
3508
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3509<!-- _______________________________________________________________________ -->
3510<div class="doc_subsubsection">
3511 <a name="i_select">'<tt>select</tt>' Instruction</a>
3512</div>
3513
3514<div class="doc_text">
3515
3516<h5>Syntax:</h5>
3517
3518<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3519 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3520</pre>
3521
3522<h5>Overview:</h5>
3523
3524<p>
3525The '<tt>select</tt>' instruction is used to choose one value based on a
3526condition, without branching.
3527</p>
3528
3529
3530<h5>Arguments:</h5>
3531
3532<p>
3533The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
3534</p>
3535
3536<h5>Semantics:</h5>
3537
3538<p>
3539If the boolean condition evaluates to true, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3540value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3541</p>
3542
3543<h5>Example:</h5>
3544
3545<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3546 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3547</pre>
3548</div>
3549
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]3550
3551<!-- _______________________________________________________________________ -->
3552<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3553 <a name="i_call">'<tt>call</tt>' Instruction</a>
3554</div>
3555
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3556<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3557
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3558<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3559<pre>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3560 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt;* &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3561</pre>
3562
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3563<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3564
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3565<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3566
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3567<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3568
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3569<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3570
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3571<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3572 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3573 <p>The optional "tail" marker indicates whether the callee function accesses
3574 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3575 function call is eligible for tail call optimization. Note that calls may
3576 be marked "tail" even if they do not occur before a <a
3577 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3578 </li>
3579 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3580 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3581 convention</a> the call should use. If none is specified, the call defaults
3582 to using C calling conventions.
3583 </li>
3584 <li>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3585 <p>'<tt>ty</tt>': shall be the signature of the pointer to function value
3586 being invoked. The argument types must match the types implied by this
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3587 signature. This type can be omitted if the function is not varargs and
3588 if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3589 </li>
3590 <li>
3591 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3592 be invoked. In most cases, this is a direct function invocation, but
3593 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3594 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3595 </li>
3596 <li>
3597 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]3598 function signature argument types. All arguments must be of
3599 <a href="#t_firstclass">first class</a> type. If the function signature
3600 indicates the function accepts a variable number of arguments, the extra
3601 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3602 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3603</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3604
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3605<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3606
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3607<p>The '<tt>call</tt>' instruction is used to cause control flow to
3608transfer to a specified function, with its incoming arguments bound to
3609the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3610instruction in the called function, control flow continues with the
3611instruction after the function call, and the return value of the
3612function is bound to the result argument. This is a simpler case of
3613the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3614
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3615<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3616
3617<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3618 %retval = call i32 %test(i32 %argc)
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3619 call i32(i8 *, ...) *%printf(i8 * %msg, i32 12, i8 42);
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3620 %X = tail call i32 %foo()
3621 %Y = tail call <a href="#callingconv">fastcc</a> i32 %foo()
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3622</pre>
3623
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3624</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3625
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3626<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3627<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3628 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3629</div>
3630
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3631<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3632
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3633<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3634
3635<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3636 &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]3637</pre>
3638
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3639<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3640
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3641<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3642the "variable argument" area of a function call. It is used to implement the
3643<tt>va_arg</tt> macro in C.</p>
3644
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3645<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3646
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3647<p>This instruction takes a <tt>va_list*</tt> value and the type of
3648the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3649increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3650actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3651
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3652<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3653
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3654<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3655type from the specified <tt>va_list</tt> and causes the
3656<tt>va_list</tt> to point to the next argument. For more information,
3657see the variable argument handling <a href="#int_varargs">Intrinsic
3658Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3659
3660<p>It is legal for this instruction to be called in a function which does not
3661take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3662function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3663
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3664<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3665href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3666argument.</p>
3667
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3668<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3669
3670<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3671
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3672</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3673
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3674<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3675<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3676<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3677
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3678<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3679
3680<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3681well known names and semantics and are required to follow certain restrictions.
3682Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3683language that does not require changing all of the transformations in LLVM when
3684adding to the language (or the bytecode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3685
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3686<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3687prefix is reserved in LLVM for intrinsic names; thus, function names may not
3688begin with this prefix. Intrinsic functions must always be external functions:
3689you cannot define the body of intrinsic functions. Intrinsic functions may
3690only be used in call or invoke instructions: it is illegal to take the address
3691of an intrinsic function. Additionally, because intrinsic functions are part
3692of the LLVM language, it is required if any are added that they be documented
3693here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3694
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3695<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3696a family of functions that perform the same operation but on different data
3697types. This is most frequent with the integer types. Since LLVM can represent
3698over 8 million different integer types, there is a way to declare an intrinsic
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3699that can be overloaded based on its arguments. Such an intrinsic will have the
3700names of its argument types encoded into its function name, each
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3701preceded by a period. For example, the <tt>llvm.ctpop</tt> function can take an
3702integer of any width. This leads to a family of functions such as
3703<tt>i32 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i32 @llvm.ctpop.i29(i29 %val)</tt>.
3704</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3705
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3706
3707<p>To learn how to add an intrinsic function, please see the
3708<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3709</p>
3710
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3711</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3712
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3713<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3714<div class="doc_subsection">
3715 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3716</div>
3717
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3718<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3719
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3720<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3721 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3722intrinsic functions. These functions are related to the similarly
3723named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3724
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3725<p>All of these functions operate on arguments that use a
3726target-specific value type "<tt>va_list</tt>". The LLVM assembly
3727language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3728transformations should be prepared to handle these functions regardless of
3729the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3730
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]3731<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]3732instruction and the variable argument handling intrinsic functions are
3733used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3734
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3735<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3736<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3737define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3738 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3739 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3740 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3741 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3742
3743 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3744 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3745
3746 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3747 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3748 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3749 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3750 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3751
3752 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3753 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3754 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3755}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3756
3757declare void @llvm.va_start(i8*)
3758declare void @llvm.va_copy(i8*, i8*)
3759declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3760</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3761</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3762
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3763</div>
3764
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3765<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3766<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3767 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3768</div>
3769
3770
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3771<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3772<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3773<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3774<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3775<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3776<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3777href="#i_va_arg">va_arg</a></tt>.</p>
3778
3779<h5>Arguments:</h5>
3780
3781<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3782
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3783<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3784
3785<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3786macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3787<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]3788<tt>va_arg</tt> will produce the first variable argument passed to the function.
3789Unlike 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]3790last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3791
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3792</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3793
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3794<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3795<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3796 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3797</div>
3798
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3799<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3800<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3801<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3802<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3803
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3804<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3805which 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]3806or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3807
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3808<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3809
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3810<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]3811
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3812<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3813
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3814<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]3815macro available in C. In a target-dependent way, it destroys the
3816<tt>va_list</tt> element to which the argument points. Calls to <a
3817href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3818<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3819<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3820
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3821</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3822
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3823<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3824<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3825 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3826</div>
3827
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3828<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3829
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3830<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3831
3832<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3833 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3834</pre>
3835
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3836<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3837
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3838<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3839from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3840
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3841<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3842
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3843<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]3844The 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]3845
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3846
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3847<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3848
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3849<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3850macro available in C. In a target-dependent way, it copies the source
3851<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3852intrinsic is necessary because the <tt><a href="#int_va_start">
3853llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3854example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3855
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3856</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3857
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3858<!-- ======================================================================= -->
3859<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3860 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3861</div>
3862
3863<div class="doc_text">
3864
3865<p>
3866LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3867Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3868These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3869stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3870href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3871Front-ends for type-safe garbage collected languages should generate these
3872intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3873href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3874</p>
3875</div>
3876
3877<!-- _______________________________________________________________________ -->
3878<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3879 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3880</div>
3881
3882<div class="doc_text">
3883
3884<h5>Syntax:</h5>
3885
3886<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3887 declare void @llvm.gcroot(&lt;ty&gt;** %ptrloc, &lt;ty2&gt;* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3888</pre>
3889
3890<h5>Overview:</h5>
3891
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3892<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]3893the code generator, and allows some metadata to be associated with it.</p>
3894
3895<h5>Arguments:</h5>
3896
3897<p>The first argument specifies the address of a stack object that contains the
3898root pointer. The second pointer (which must be either a constant or a global
3899value address) contains the meta-data to be associated with the root.</p>
3900
3901<h5>Semantics:</h5>
3902
3903<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3904location. At compile-time, the code generator generates information to allow
3905the runtime to find the pointer at GC safe points.
3906</p>
3907
3908</div>
3909
3910
3911<!-- _______________________________________________________________________ -->
3912<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3913 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3914</div>
3915
3916<div class="doc_text">
3917
3918<h5>Syntax:</h5>
3919
3920<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3921 declare i8 * @llvm.gcread(i8 * %ObjPtr, i8 ** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3922</pre>
3923
3924<h5>Overview:</h5>
3925
3926<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
3927locations, allowing garbage collector implementations that require read
3928barriers.</p>
3929
3930<h5>Arguments:</h5>
3931
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]3932<p>The second argument is the address to read from, which should be an address
3933allocated from the garbage collector. The first object is a pointer to the
3934start of the referenced object, if needed by the language runtime (otherwise
3935null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3936
3937<h5>Semantics:</h5>
3938
3939<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
3940instruction, but may be replaced with substantially more complex code by the
3941garbage collector runtime, as needed.</p>
3942
3943</div>
3944
3945
3946<!-- _______________________________________________________________________ -->
3947<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3948 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3949</div>
3950
3951<div class="doc_text">
3952
3953<h5>Syntax:</h5>
3954
3955<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3956 declare void @llvm.gcwrite(i8 * %P1, i8 * %Obj, i8 ** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3957</pre>
3958
3959<h5>Overview:</h5>
3960
3961<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
3962locations, allowing garbage collector implementations that require write
3963barriers (such as generational or reference counting collectors).</p>
3964
3965<h5>Arguments:</h5>
3966
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]3967<p>The first argument is the reference to store, the second is the start of the
3968object to store it to, and the third is the address of the field of Obj to
3969store to. If the runtime does not require a pointer to the object, Obj may be
3970null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3971
3972<h5>Semantics:</h5>
3973
3974<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
3975instruction, but may be replaced with substantially more complex code by the
3976garbage collector runtime, as needed.</p>
3977
3978</div>
3979
3980
3981
3982<!-- ======================================================================= -->
3983<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]3984 <a name="int_codegen">Code Generator Intrinsics</a>
3985</div>
3986
3987<div class="doc_text">
3988<p>
3989These intrinsics are provided by LLVM to expose special features that may only
3990be implemented with code generator support.
3991</p>
3992
3993</div>
3994
3995<!-- _______________________________________________________________________ -->
3996<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3997 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]3998</div>
3999
4000<div class="doc_text">
4001
4002<h5>Syntax:</h5>
4003<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4004 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4005</pre>
4006
4007<h5>Overview:</h5>
4008
4009<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4010The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4011target-specific value indicating the return address of the current function
4012or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4013</p>
4014
4015<h5>Arguments:</h5>
4016
4017<p>
4018The argument to this intrinsic indicates which function to return the address
4019for. Zero indicates the calling function, one indicates its caller, etc. The
4020argument is <b>required</b> to be a constant integer value.
4021</p>
4022
4023<h5>Semantics:</h5>
4024
4025<p>
4026The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4027the return address of the specified call frame, or zero if it cannot be
4028identified. The value returned by this intrinsic is likely to be incorrect or 0
4029for arguments other than zero, so it should only be used for debugging purposes.
4030</p>
4031
4032<p>
4033Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4034aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4035source-language caller.
4036</p>
4037</div>
4038
4039
4040<!-- _______________________________________________________________________ -->
4041<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4042 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4043</div>
4044
4045<div class="doc_text">
4046
4047<h5>Syntax:</h5>
4048<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4049 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4050</pre>
4051
4052<h5>Overview:</h5>
4053
4054<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4055The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4056target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4057</p>
4058
4059<h5>Arguments:</h5>
4060
4061<p>
4062The argument to this intrinsic indicates which function to return the frame
4063pointer for. Zero indicates the calling function, one indicates its caller,
4064etc. The argument is <b>required</b> to be a constant integer value.
4065</p>
4066
4067<h5>Semantics:</h5>
4068
4069<p>
4070The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4071the frame address of the specified call frame, or zero if it cannot be
4072identified. The value returned by this intrinsic is likely to be incorrect or 0
4073for arguments other than zero, so it should only be used for debugging purposes.
4074</p>
4075
4076<p>
4077Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4078aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4079source-language caller.
4080</p>
4081</div>
4082
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4083<!-- _______________________________________________________________________ -->
4084<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4085 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4086</div>
4087
4088<div class="doc_text">
4089
4090<h5>Syntax:</h5>
4091<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4092 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4093</pre>
4094
4095<h5>Overview:</h5>
4096
4097<p>
4098The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4099the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4100<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4101features like scoped automatic variable sized arrays in C99.
4102</p>
4103
4104<h5>Semantics:</h5>
4105
4106<p>
4107This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4108href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4109<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4110<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4111state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4112practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4113that were allocated after the <tt>llvm.stacksave</tt> was executed.
4114</p>
4115
4116</div>
4117
4118<!-- _______________________________________________________________________ -->
4119<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4120 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4121</div>
4122
4123<div class="doc_text">
4124
4125<h5>Syntax:</h5>
4126<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4127 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4128</pre>
4129
4130<h5>Overview:</h5>
4131
4132<p>
4133The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4134the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4135href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4136useful for implementing language features like scoped automatic variable sized
4137arrays in C99.
4138</p>
4139
4140<h5>Semantics:</h5>
4141
4142<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4143See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4144</p>
4145
4146</div>
4147
4148
4149<!-- _______________________________________________________________________ -->
4150<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4151 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4152</div>
4153
4154<div class="doc_text">
4155
4156<h5>Syntax:</h5>
4157<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4158 declare void @llvm.prefetch(i8 * &lt;address&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4159 i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4160</pre>
4161
4162<h5>Overview:</h5>
4163
4164
4165<p>
4166The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4167a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4168no
4169effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4170characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4171</p>
4172
4173<h5>Arguments:</h5>
4174
4175<p>
4176<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4177determining if the fetch should be for a read (0) or write (1), and
4178<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4179locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4180<tt>locality</tt> arguments must be constant integers.
4181</p>
4182
4183<h5>Semantics:</h5>
4184
4185<p>
4186This intrinsic does not modify the behavior of the program. In particular,
4187prefetches cannot trap and do not produce a value. On targets that support this
4188intrinsic, the prefetch can provide hints to the processor cache for better
4189performance.
4190</p>
4191
4192</div>
4193
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4194<!-- _______________________________________________________________________ -->
4195<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4196 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4197</div>
4198
4199<div class="doc_text">
4200
4201<h5>Syntax:</h5>
4202<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4203 declare void @llvm.pcmarker( i32 &lt;id&gt; )
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4204</pre>
4205
4206<h5>Overview:</h5>
4207
4208
4209<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4210The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4211(PC) in a region of
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4212code to simulators and other tools. The method is target specific, but it is
4213expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohendc6bfea2005-11-11 02:15:27 +0000[diff] [blame]4214The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnere64d41d2005-11-15 06:07:55 +0000[diff] [blame]4215after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4216optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4217correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4218</p>
4219
4220<h5>Arguments:</h5>
4221
4222<p>
4223<tt>id</tt> is a numerical id identifying the marker.
4224</p>
4225
4226<h5>Semantics:</h5>
4227
4228<p>
4229This intrinsic does not modify the behavior of the program. Backends that do not
4230support this intrinisic may ignore it.
4231</p>
4232
4233</div>
4234
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4235<!-- _______________________________________________________________________ -->
4236<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4237 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4238</div>
4239
4240<div class="doc_text">
4241
4242<h5>Syntax:</h5>
4243<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4244 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4245</pre>
4246
4247<h5>Overview:</h5>
4248
4249
4250<p>
4251The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4252counter register (or similar low latency, high accuracy clocks) on those targets
4253that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4254As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4255should only be used for small timings.
4256</p>
4257
4258<h5>Semantics:</h5>
4259
4260<p>
4261When directly supported, reading the cycle counter should not modify any memory.
4262Implementations are allowed to either return a application specific value or a
4263system wide value. On backends without support, this is lowered to a constant 0.
4264</p>
4265
4266</div>
4267
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4268<!-- ======================================================================= -->
4269<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4270 <a name="int_libc">Standard C Library Intrinsics</a>
4271</div>
4272
4273<div class="doc_text">
4274<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4275LLVM provides intrinsics for a few important standard C library functions.
4276These intrinsics allow source-language front-ends to pass information about the
4277alignment of the pointer arguments to the code generator, providing opportunity
4278for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4279</p>
4280
4281</div>
4282
4283<!-- _______________________________________________________________________ -->
4284<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4285 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4286</div>
4287
4288<div class="doc_text">
4289
4290<h5>Syntax:</h5>
4291<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4292 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4293 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4294 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4295 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4296</pre>
4297
4298<h5>Overview:</h5>
4299
4300<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4301The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4302location to the destination location.
4303</p>
4304
4305<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4306Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4307intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4308</p>
4309
4310<h5>Arguments:</h5>
4311
4312<p>
4313The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4314the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4315specifying the number of bytes to copy, and the fourth argument is the alignment
4316of the source and destination locations.
4317</p>
4318
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4319<p>
4320If 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]4321the caller guarantees that both the source and destination pointers are aligned
4322to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4323</p>
4324
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4325<h5>Semantics:</h5>
4326
4327<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4328The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4329location to the destination location, which are not allowed to overlap. It
4330copies "len" bytes of memory over. If the argument is known to be aligned to
4331some boundary, this can be specified as the fourth argument, otherwise it should
4332be set to 0 or 1.
4333</p>
4334</div>
4335
4336
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4337<!-- _______________________________________________________________________ -->
4338<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4339 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4340</div>
4341
4342<div class="doc_text">
4343
4344<h5>Syntax:</h5>
4345<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4346 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4347 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4348 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4349 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4350</pre>
4351
4352<h5>Overview:</h5>
4353
4354<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4355The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4356location to the destination location. It is similar to the
4357'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4358</p>
4359
4360<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4361Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4362intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4363</p>
4364
4365<h5>Arguments:</h5>
4366
4367<p>
4368The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4369the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4370specifying the number of bytes to copy, and the fourth argument is the alignment
4371of the source and destination locations.
4372</p>
4373
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4374<p>
4375If 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]4376the caller guarantees that the source and destination pointers are aligned to
4377that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4378</p>
4379
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4380<h5>Semantics:</h5>
4381
4382<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4383The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4384location to the destination location, which may overlap. It
4385copies "len" bytes of memory over. If the argument is known to be aligned to
4386some boundary, this can be specified as the fourth argument, otherwise it should
4387be set to 0 or 1.
4388</p>
4389</div>
4390
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4391
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4392<!-- _______________________________________________________________________ -->
4393<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4394 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4395</div>
4396
4397<div class="doc_text">
4398
4399<h5>Syntax:</h5>
4400<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4401 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4402 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4403 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4404 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4405</pre>
4406
4407<h5>Overview:</h5>
4408
4409<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4410The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4411byte value.
4412</p>
4413
4414<p>
4415Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4416does not return a value, and takes an extra alignment argument.
4417</p>
4418
4419<h5>Arguments:</h5>
4420
4421<p>
4422The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4423byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4424argument specifying the number of bytes to fill, and the fourth argument is the
4425known alignment of destination location.
4426</p>
4427
4428<p>
4429If 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]4430the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4431</p>
4432
4433<h5>Semantics:</h5>
4434
4435<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4436The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4437the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4438destination location. If the argument is known to be aligned to some boundary,
4439this can be specified as the fourth argument, otherwise it should be set to 0 or
44401.
4441</p>
4442</div>
4443
4444
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4445<!-- _______________________________________________________________________ -->
4446<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4447 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4448</div>
4449
4450<div class="doc_text">
4451
4452<h5>Syntax:</h5>
4453<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4454 declare float @llvm.sqrt.f32(float %Val)
4455 declare double @llvm.sqrt.f64(double %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4456</pre>
4457
4458<h5>Overview:</h5>
4459
4460<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4461The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4462returning the same value as the libm '<tt>sqrt</tt>' function would. Unlike
4463<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4464negative numbers (which allows for better optimization).
4465</p>
4466
4467<h5>Arguments:</h5>
4468
4469<p>
4470The argument and return value are floating point numbers of the same type.
4471</p>
4472
4473<h5>Semantics:</h5>
4474
4475<p>
4476This function returns the sqrt of the specified operand if it is a positive
4477floating point number.
4478</p>
4479</div>
4480
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4481<!-- _______________________________________________________________________ -->
4482<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4483 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4484</div>
4485
4486<div class="doc_text">
4487
4488<h5>Syntax:</h5>
4489<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4490 declare float @llvm.powi.f32(float %Val, i32 %power)
4491 declare double @llvm.powi.f64(double %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4492</pre>
4493
4494<h5>Overview:</h5>
4495
4496<p>
4497The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4498specified (positive or negative) power. The order of evaluation of
4499multiplications is not defined.
4500</p>
4501
4502<h5>Arguments:</h5>
4503
4504<p>
4505The second argument is an integer power, and the first is a value to raise to
4506that power.
4507</p>
4508
4509<h5>Semantics:</h5>
4510
4511<p>
4512This function returns the first value raised to the second power with an
4513unspecified sequence of rounding operations.</p>
4514</div>
4515
4516
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4517<!-- ======================================================================= -->
4518<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4519 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4520</div>
4521
4522<div class="doc_text">
4523<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4524LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4525These allow efficient code generation for some algorithms.
4526</p>
4527
4528</div>
4529
4530<!-- _______________________________________________________________________ -->
4531<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4532 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4533</div>
4534
4535<div class="doc_text">
4536
4537<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4538<p>This is an overloaded intrinsic function. You can use bswap on any integer
4539type that is an even number of bytes (i.e. BitWidth % 16 == 0). Note the suffix
4540that includes the type for the result and the operand.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4541<pre>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4542 declare i16 @llvm.bswap.i16.i16(i16 &lt;id&gt;)
4543 declare i32 @llvm.bswap.i32.i32(i32 &lt;id&gt;)
Reid Spencer403a1c42007-04-02 00:19:52 +0000[diff] [blame]4544 declare i64 @llvm.bswap.i64.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4545</pre>
4546
4547<h5>Overview:</h5>
4548
4549<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]4550The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4551values with an even number of bytes (positive multiple of 16 bits). These are
4552useful for performing operations on data that is not in the target's native
4553byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4554</p>
4555
4556<h5>Semantics:</h5>
4557
4558<p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4559The <tt>llvm.bswap.16.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4560and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4561intrinsic returns an i32 value that has the four bytes of the input i32
4562swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4563i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48.i48</tt>,
4564<tt>llvm.bswap.i64.i64</tt> and other intrinsics extend this concept to
4565additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4566</p>
4567
4568</div>
4569
4570<!-- _______________________________________________________________________ -->
4571<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4572 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4573</div>
4574
4575<div class="doc_text">
4576
4577<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4578<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4579width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4580<pre>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4581 declare i32 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4582 declare i32 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4583 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4584 declare i32 @llvm.ctpop.i64(i64 &lt;src&gt;)
4585 declare i32 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4586</pre>
4587
4588<h5>Overview:</h5>
4589
4590<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]4591The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4592value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4593</p>
4594
4595<h5>Arguments:</h5>
4596
4597<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4598The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4599integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4600</p>
4601
4602<h5>Semantics:</h5>
4603
4604<p>
4605The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4606</p>
4607</div>
4608
4609<!-- _______________________________________________________________________ -->
4610<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4611 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4612</div>
4613
4614<div class="doc_text">
4615
4616<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4617<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4618integer bit width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4619<pre>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4620 declare i32 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4621 declare i32 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4622 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4623 declare i32 @llvm.ctlz.i64(i64 &lt;src&gt;)
4624 declare i32 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4625</pre>
4626
4627<h5>Overview:</h5>
4628
4629<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4630The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4631leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4632</p>
4633
4634<h5>Arguments:</h5>
4635
4636<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4637The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4638integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4639</p>
4640
4641<h5>Semantics:</h5>
4642
4643<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4644The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4645in 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]4646of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4647</p>
4648</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4649
4650
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4651
4652<!-- _______________________________________________________________________ -->
4653<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4654 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4655</div>
4656
4657<div class="doc_text">
4658
4659<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4660<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4661integer bit width. Not all targets support all bit widths however.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4662<pre>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4663 declare i32 @llvm.cttz.i8 (i8 &lt;src&gt;)
4664 declare i32 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4665 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4666 declare i32 @llvm.cttz.i64(i64 &lt;src&gt;)
4667 declare i32 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4668</pre>
4669
4670<h5>Overview:</h5>
4671
4672<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4673The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4674trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4675</p>
4676
4677<h5>Arguments:</h5>
4678
4679<p>
4680The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4681integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4682</p>
4683
4684<h5>Semantics:</h5>
4685
4686<p>
4687The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4688in a variable. If the src == 0 then the result is the size in bits of the type
4689of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4690</p>
4691</div>
4692
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]4693<!-- _______________________________________________________________________ -->
4694<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4695 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4696</div>
4697
4698<div class="doc_text">
4699
4700<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4701<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4702on any integer bit width.
4703<pre>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4704 declare i17 @llvm.part.select.i17.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4705 declare i29 @llvm.part.select.i29.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4706</pre>
4707
4708<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4709<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4710range of bits from an integer value and returns them in the same bit width as
4711the original value.</p>
4712
4713<h5>Arguments:</h5>
4714<p>The first argument, <tt>%val</tt> and the result may be integer types of
4715any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4716arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4717
4718<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4719<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4720of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4721<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4722operates in forward mode.</p>
4723<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4724right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4725only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4726<ol>
4727 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4728 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4729 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4730 to determine the number of bits to retain.</li>
4731 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4732 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4733</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]4734<p>In reverse mode, a similar computation is made except that the bits are
4735returned in the reverse order. So, for example, if <tt>X</tt> has the value
4736<tt>i16 0x0ACF (101011001111)</tt> and we apply
4737<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4738<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4739</div>
4740
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4741<div class="doc_subsubsection">
4742 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4743</div>
4744
4745<div class="doc_text">
4746
4747<h5>Syntax:</h5>
4748<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4749on any integer bit width.
4750<pre>
4751 declare i17 @llvm.part.set.i17.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4752 declare i29 @llvm.part.set.i29.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
4753</pre>
4754
4755<h5>Overview:</h5>
4756<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4757of bits in an integer value with another integer value. It returns the integer
4758with the replaced bits.</p>
4759
4760<h5>Arguments:</h5>
4761<p>The first argument, <tt>%val</tt> and the result may be integer types of
4762any bit width but they must have the same bit width. <tt>%val</tt> is the value
4763whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4764integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4765type since they specify only a bit index.</p>
4766
4767<h5>Semantics:</h5>
4768<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4769of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4770<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4771operates in forward mode.</p>
4772<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4773truncating it down to the size of the replacement area or zero extending it
4774up to that size.</p>
4775<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
4776are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
4777in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
4778to the <tt>%hi</tt>th bit.
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]4779<p>In reverse mode, a similar computation is made except that the bits are
4780reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
4781<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4782<h5>Examples:</h5>
4783<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]4784 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]4785 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
4786 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
4787 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]4788 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]4789</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4790</div>
4791
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4792<!-- ======================================================================= -->
4793<div class="doc_subsection">
4794 <a name="int_debugger">Debugger Intrinsics</a>
4795</div>
4796
4797<div class="doc_text">
4798<p>
4799The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
4800are described in the <a
4801href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
4802Debugging</a> document.
4803</p>
4804</div>
4805
4806
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]4807<!-- ======================================================================= -->
4808<div class="doc_subsection">
4809 <a name="int_eh">Exception Handling Intrinsics</a>
4810</div>
4811
4812<div class="doc_text">
4813<p> The LLVM exception handling intrinsics (which all start with
4814<tt>llvm.eh.</tt> prefix), are described in the <a
4815href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
4816Handling</a> document. </p>
4817</div>
4818
4819
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4820<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4821<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]4822<address>
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4827
4828 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]4829 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]4830 Last modified: $Date$
4831</address>
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