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gerrit-public.fairphone.software / toolchain / llvm-project / 08143e397df8c75e8c6aa217b1bc3e65c41bba16 / . / 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>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]180 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]183 </ol>
184 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]185 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]186 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]187 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]188 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
189 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
190 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]191 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
192 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]193 </ol>
194 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]195 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]196 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]197 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]198 <ol>
199 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]200 </ol>
201 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]202 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]203 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]204 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]205 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]206 </ol>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]207 <ol>
208 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]209 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]210 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]211 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]214</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]215
216<div class="doc_author">
217 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
218 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]219</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]220
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]221<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]222<div class="doc_section"> <a name="abstract">Abstract </a></div>
223<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]224
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]225<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]226<p>This document is a reference manual for the LLVM assembly language.
227LLVM is an SSA based representation that provides type safety,
228low-level operations, flexibility, and the capability of representing
229'all' high-level languages cleanly. It is the common code
230representation used throughout all phases of the LLVM compilation
231strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]232</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]233
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]234<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]235<div class="doc_section"> <a name="introduction">Introduction</a> </div>
236<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]237
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]238<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]239
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]240<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]241different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]242representation (suitable for fast loading by a Just-In-Time compiler),
243and as a human readable assembly language representation. This allows
244LLVM to provide a powerful intermediate representation for efficient
245compiler transformations and analysis, while providing a natural means
246to debug and visualize the transformations. The three different forms
247of LLVM are all equivalent. This document describes the human readable
248representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]249
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]250<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]251while being expressive, typed, and extensible at the same time. It
252aims to be a "universal IR" of sorts, by being at a low enough level
253that high-level ideas may be cleanly mapped to it (similar to how
254microprocessors are "universal IR's", allowing many source languages to
255be mapped to them). By providing type information, LLVM can be used as
256the target of optimizations: for example, through pointer analysis, it
257can be proven that a C automatic variable is never accessed outside of
258the current function... allowing it to be promoted to a simple SSA
259value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]261</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]262
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]263<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]264<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]265
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]266<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]268<p>It is important to note that this document describes 'well formed'
269LLVM assembly language. There is a difference between what the parser
270accepts and what is considered 'well formed'. For example, the
271following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]272
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]273<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]275%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]276</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]277</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]278
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]279<p>...because the definition of <tt>%x</tt> does not dominate all of
280its uses. The LLVM infrastructure provides a verification pass that may
281be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]282automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]283the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]284by the verifier pass indicate bugs in transformation passes or input to
285the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]286</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]287
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]288<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]289
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]290<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]291<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]292<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]293
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]294<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]296 <p>LLVM identifiers come in two basic types: global and local. Global
297 identifiers (functions, global variables) begin with the @ character. Local
298 identifiers (register names, types) begin with the % character. Additionally,
299 there are three different formats for identifiers, for different purposes:
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]300
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]301<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]302 <li>Named values are represented as a string of characters with their prefix.
303 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
304 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]305 Identifiers which require other characters in their names can be surrounded
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]306 with quotes. In this way, anything except a <tt>&quot;</tt> character can
307 be used in a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]308
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]309 <li>Unnamed values are represented as an unsigned numeric value with their
310 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]311
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]312 <li>Constants, which are described in a <a href="#constants">section about
313 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]314</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]315
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]316<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]317don't need to worry about name clashes with reserved words, and the set of
318reserved words may be expanded in the future without penalty. Additionally,
319unnamed identifiers allow a compiler to quickly come up with a temporary
320variable without having to avoid symbol table conflicts.</p>
321
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]322<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]323languages. There are keywords for different opcodes
324('<tt><a href="#i_add">add</a></tt>',
325 '<tt><a href="#i_bitcast">bitcast</a></tt>',
326 '<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]327href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]328and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]329none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]330
331<p>Here is an example of LLVM code to multiply the integer variable
332'<tt>%X</tt>' by 8:</p>
333
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]334<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]335
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]336<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]337<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]338%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]339</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]340</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]341
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]342<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]343
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]344<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]345<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]346%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]347</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]348</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]349
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]350<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]351
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]352<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]353<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]354<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
355<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
356%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]357</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]358</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]359
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]360<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
361important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]363<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]364
365 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
366 line.</li>
367
368 <li>Unnamed temporaries are created when the result of a computation is not
369 assigned to a named value.</li>
370
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]371 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]373</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]375<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376demonstrating instructions, we will follow an instruction with a comment that
377defines the type and name of value produced. Comments are shown in italic
378text.</p>
379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]380</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]381
382<!-- *********************************************************************** -->
383<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
384<!-- *********************************************************************** -->
385
386<!-- ======================================================================= -->
387<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
388</div>
389
390<div class="doc_text">
391
392<p>LLVM programs are composed of "Module"s, each of which is a
393translation unit of the input programs. Each module consists of
394functions, global variables, and symbol table entries. Modules may be
395combined together with the LLVM linker, which merges function (and
396global variable) definitions, resolves forward declarations, and merges
397symbol table entries. Here is an example of the "hello world" module:</p>
398
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]400<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]401<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
402 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]403
404<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]405<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]406
407<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]408define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]409 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]410 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]411 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]412
413 <i>; Call puts function to write out the string to stdout...</i>
414 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]415 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]416 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]417 href="#i_ret">ret</a> i32 0<br>}<br>
418</pre>
419</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]420
421<p>This example is made up of a <a href="#globalvars">global variable</a>
422named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
423function, and a <a href="#functionstructure">function definition</a>
424for "<tt>main</tt>".</p>
425
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426<p>In general, a module is made up of a list of global values,
427where both functions and global variables are global values. Global values are
428represented by a pointer to a memory location (in this case, a pointer to an
429array of char, and a pointer to a function), and have one of the following <a
430href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]431
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432</div>
433
434<!-- ======================================================================= -->
435<div class="doc_subsection">
436 <a name="linkage">Linkage Types</a>
437</div>
438
439<div class="doc_text">
440
441<p>
442All Global Variables and Functions have one of the following types of linkage:
443</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]444
445<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]447 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
449 <dd>Global values with internal linkage are only directly accessible by
450 objects in the current module. In particular, linking code into a module with
451 an internal global value may cause the internal to be renamed as necessary to
452 avoid collisions. Because the symbol is internal to the module, all
453 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]454 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]455 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]457 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]459 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
460 the same name when linkage occurs. This is typically used to implement
461 inline functions, templates, or other code which must be generated in each
462 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
463 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]464 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]466 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
468 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
469 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]470 used for globals that may be emitted in multiple translation units, but that
471 are not guaranteed to be emitted into every translation unit that uses them.
472 One example of this are common globals in C, such as "<tt>int X;</tt>" at
473 global scope.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]474 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]475
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]476 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
478 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
479 pointer to array type. When two global variables with appending linkage are
480 linked together, the two global arrays are appended together. This is the
481 LLVM, typesafe, equivalent of having the system linker append together
482 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]484
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]485 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
486 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
487 until linked, if not linked, the symbol becomes null instead of being an
488 undefined reference.
489 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]490
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]492
493 <dd>If none of the above identifiers are used, the global is externally
494 visible, meaning that it participates in linkage and can be used to resolve
495 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]497</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]498
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]499 <p>
500 The next two types of linkage are targeted for Microsoft Windows platform
501 only. They are designed to support importing (exporting) symbols from (to)
502 DLLs.
503 </p>
504
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]505 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]506 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
507
508 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
509 or variable via a global pointer to a pointer that is set up by the DLL
510 exporting the symbol. On Microsoft Windows targets, the pointer name is
511 formed by combining <code>_imp__</code> and the function or variable name.
512 </dd>
513
514 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
515
516 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
517 pointer to a pointer in a DLL, so that it can be referenced with the
518 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
519 name is formed by combining <code>_imp__</code> and the function or variable
520 name.
521 </dd>
522
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]523</dl>
524
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]525<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
527variable and was linked with this one, one of the two would be renamed,
528preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
529external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]530outside of the current module.</p>
531<p>It is illegal for a function <i>declaration</i>
532to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]533or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]534<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
535linkages.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]536</div>
537
538<!-- ======================================================================= -->
539<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]540 <a name="callingconv">Calling Conventions</a>
541</div>
542
543<div class="doc_text">
544
545<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
546and <a href="#i_invoke">invokes</a> can all have an optional calling convention
547specified for the call. The calling convention of any pair of dynamic
548caller/callee must match, or the behavior of the program is undefined. The
549following calling conventions are supported by LLVM, and more may be added in
550the future:</p>
551
552<dl>
553 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
554
555 <dd>This calling convention (the default if no other calling convention is
556 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]557 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]558 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]559 </dd>
560
561 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
562
563 <dd>This calling convention attempts to make calls as fast as possible
564 (e.g. by passing things in registers). This calling convention allows the
565 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerc792eb32005-05-06 23:08:23 +0000[diff] [blame]566 without having to conform to an externally specified ABI. Implementations of
567 this convention should allow arbitrary tail call optimization to be supported.
568 This calling convention does not support varargs and requires the prototype of
569 all callees to exactly match the prototype of the function definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]570 </dd>
571
572 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
573
574 <dd>This calling convention attempts to make code in the caller as efficient
575 as possible under the assumption that the call is not commonly executed. As
576 such, these calls often preserve all registers so that the call does not break
577 any live ranges in the caller side. This calling convention does not support
578 varargs and requires the prototype of all callees to exactly match the
579 prototype of the function definition.
580 </dd>
581
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]582 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]583
584 <dd>Any calling convention may be specified by number, allowing
585 target-specific calling conventions to be used. Target specific calling
586 conventions start at 64.
587 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]588</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]589
590<p>More calling conventions can be added/defined on an as-needed basis, to
591support pascal conventions or any other well-known target-independent
592convention.</p>
593
594</div>
595
596<!-- ======================================================================= -->
597<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]598 <a name="visibility">Visibility Styles</a>
599</div>
600
601<div class="doc_text">
602
603<p>
604All Global Variables and Functions have one of the following visibility styles:
605</p>
606
607<dl>
608 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
609
610 <dd>On ELF, default visibility means that the declaration is visible to other
611 modules and, in shared libraries, means that the declared entity may be
612 overridden. On Darwin, default visibility means that the declaration is
613 visible to other modules. Default visibility corresponds to "external
614 linkage" in the language.
615 </dd>
616
617 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
618
619 <dd>Two declarations of an object with hidden visibility refer to the same
620 object if they are in the same shared object. Usually, hidden visibility
621 indicates that the symbol will not be placed into the dynamic symbol table,
622 so no other module (executable or shared library) can reference it
623 directly.
624 </dd>
625
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]626 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
627
628 <dd>On ELF, protected visibility indicates that the symbol will be placed in
629 the dynamic symbol table, but that references within the defining module will
630 bind to the local symbol. That is, the symbol cannot be overridden by another
631 module.
632 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]633</dl>
634
635</div>
636
637<!-- ======================================================================= -->
638<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]639 <a name="globalvars">Global Variables</a>
640</div>
641
642<div class="doc_text">
643
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]644<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]645instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]646an explicit section to be placed in, and may have an optional explicit alignment
647specified. A variable may be defined as "thread_local", which means that it
648will not be shared by threads (each thread will have a separated copy of the
649variable). A variable may be defined as a global "constant," which indicates
650that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]651optimization, allowing the global data to be placed in the read-only section of
652an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]653cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]654
655<p>
656LLVM explicitly allows <em>declarations</em> of global variables to be marked
657constant, even if the final definition of the global is not. This capability
658can be used to enable slightly better optimization of the program, but requires
659the language definition to guarantee that optimizations based on the
660'constantness' are valid for the translation units that do not include the
661definition.
662</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]663
664<p>As SSA values, global variables define pointer values that are in
665scope (i.e. they dominate) all basic blocks in the program. Global
666variables always define a pointer to their "content" type because they
667describe a region of memory, and all memory objects in LLVM are
668accessed through pointers.</p>
669
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]670<p>LLVM allows an explicit section to be specified for globals. If the target
671supports it, it will emit globals to the section specified.</p>
672
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]673<p>An explicit alignment may be specified for a global. If not present, or if
674the alignment is set to zero, the alignment of the global is set by the target
675to whatever it feels convenient. If an explicit alignment is specified, the
676global is forced to have at least that much alignment. All alignments must be
677a power of 2.</p>
678
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]679<p>For example, the following defines a global with an initializer, section,
680 and alignment:</p>
681
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]682<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]683<pre>
Chris Lattner0a2d0992007-07-13 20:01:46 +0000[diff] [blame]684@G = constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]685</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]686</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]687
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]688</div>
689
690
691<!-- ======================================================================= -->
692<div class="doc_subsection">
693 <a name="functionstructure">Functions</a>
694</div>
695
696<div class="doc_text">
697
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]698<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
699an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]700<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]701<a href="#callingconv">calling convention</a>, a return type, an optional
702<a href="#paramattrs">parameter attribute</a> for the return type, a function
703name, a (possibly empty) argument list (each with optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]704<a href="#paramattrs">parameter attributes</a>), an optional section, an
705optional alignment, an opening curly brace, a list of basic blocks, and a
706closing curly brace.
707
708LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
709optional <a href="#linkage">linkage type</a>, an optional
710<a href="#visibility">visibility style</a>, an optional
711<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]712<a href="#paramattrs">parameter attribute</a> for the return type, a function
713name, a possibly empty list of arguments, and an optional alignment.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]714
715<p>A function definition contains a list of basic blocks, forming the CFG for
716the function. Each basic block may optionally start with a label (giving the
717basic block a symbol table entry), contains a list of instructions, and ends
718with a <a href="#terminators">terminator</a> instruction (such as a branch or
719function return).</p>
720
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]721<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]722executed on entrance to the function, and it is not allowed to have predecessor
723basic blocks (i.e. there can not be any branches to the entry block of a
724function). Because the block can have no predecessors, it also cannot have any
725<a href="#i_phi">PHI nodes</a>.</p>
726
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]727<p>LLVM allows an explicit section to be specified for functions. If the target
728supports it, it will emit functions to the section specified.</p>
729
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]730<p>An explicit alignment may be specified for a function. If not present, or if
731the alignment is set to zero, the alignment of the function is set by the target
732to whatever it feels convenient. If an explicit alignment is specified, the
733function is forced to have at least that much alignment. All alignments must be
734a power of 2.</p>
735
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]736</div>
737
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]738
739<!-- ======================================================================= -->
740<div class="doc_subsection">
741 <a name="aliasstructure">Aliases</a>
742</div>
743<div class="doc_text">
744 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikovb18f8f82007-04-28 13:45:00 +0000[diff] [blame]745 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]746 optional <a href="#linkage">linkage type</a>, and an
747 optional <a href="#visibility">visibility style</a>.</p>
748
749 <h5>Syntax:</h5>
750
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]751<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]752<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]753@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]754</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]755</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]756
757</div>
758
759
760
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]761<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]762<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
763<div class="doc_text">
764 <p>The return type and each parameter of a function type may have a set of
765 <i>parameter attributes</i> associated with them. Parameter attributes are
766 used to communicate additional information about the result or parameters of
767 a function. Parameter attributes are considered to be part of the function
768 type so two functions types that differ only by the parameter attributes
769 are different function types.</p>
770
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]771 <p>Parameter attributes are simple keywords that follow the type specified. If
772 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]773 example:</p>
774
775<div class="doc_code">
776<pre>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]777%someFunc = i16 (i8 signext %someParam) zeroext
778%someFunc = i16 (i8 zeroext %someParam) zeroext
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]779</pre>
780</div>
781
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]782 <p>Note that the two function types above are unique because the parameter has
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]783 a different attribute (<tt>signext</tt> in the first one, <tt>zeroext</tt> in
784 the second). Also note that the attribute for the function result
785 (<tt>zeroext</tt>) comes immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]786
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]787 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]788 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]789 <dt><tt>zeroext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]790 <dd>This indicates that the parameter should be zero extended just before
791 a call to this function.</dd>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]792 <dt><tt>signext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]793 <dd>This indicates that the parameter should be sign extended just before
794 a call to this function.</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]795 <dt><tt>inreg</tt></dt>
796 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]797 possible) during assembling function call. Support for this attribute is
798 target-specific</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]799 <dt><tt>sret</tt></dt>
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]800 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]801 that is the return value of the function in the source program.</dd>
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]802 <dt><tt>noalias</tt></dt>
803 <dd>This indicates that the parameter not alias any other object or any
804 other "noalias" objects during the function call.
Reid Spencer9d1700e2007-03-22 02:18:56 +0000[diff] [blame]805 <dt><tt>noreturn</tt></dt>
806 <dd>This function attribute indicates that the function never returns. This
807 indicates to LLVM that every call to this function should be treated as if
808 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]809 <dt><tt>nounwind</tt></dt>
810 <dd>This function attribute indicates that the function type does not use
811 the unwind instruction and does not allow stack unwinding to propagate
812 through it.</dd>
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]813 <dt><tt>nest</tt></dt>
814 <dd>This indicates that the parameter can be excised using the
815 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]816 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]817
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]818</div>
819
820<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]821<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]822 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]823</div>
824
825<div class="doc_text">
826<p>
827Modules may contain "module-level inline asm" blocks, which corresponds to the
828GCC "file scope inline asm" blocks. These blocks are internally concatenated by
829LLVM and treated as a single unit, but may be separated in the .ll file if
830desired. The syntax is very simple:
831</p>
832
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]833<div class="doc_code">
834<pre>
835module asm "inline asm code goes here"
836module asm "more can go here"
837</pre>
838</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]839
840<p>The strings can contain any character by escaping non-printable characters.
841 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
842 for the number.
843</p>
844
845<p>
846 The inline asm code is simply printed to the machine code .s file when
847 assembly code is generated.
848</p>
849</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]850
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]851<!-- ======================================================================= -->
852<div class="doc_subsection">
853 <a name="datalayout">Data Layout</a>
854</div>
855
856<div class="doc_text">
857<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]858data is to be laid out in memory. The syntax for the data layout is simply:</p>
859<pre> target datalayout = "<i>layout specification</i>"</pre>
860<p>The <i>layout specification</i> consists of a list of specifications
861separated by the minus sign character ('-'). Each specification starts with a
862letter and may include other information after the letter to define some
863aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]864<dl>
865 <dt><tt>E</tt></dt>
866 <dd>Specifies that the target lays out data in big-endian form. That is, the
867 bits with the most significance have the lowest address location.</dd>
868 <dt><tt>e</tt></dt>
869 <dd>Specifies that hte target lays out data in little-endian form. That is,
870 the bits with the least significance have the lowest address location.</dd>
871 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
872 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
873 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
874 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
875 too.</dd>
876 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
877 <dd>This specifies the alignment for an integer type of a given bit
878 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
879 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
880 <dd>This specifies the alignment for a vector type of a given bit
881 <i>size</i>.</dd>
882 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
883 <dd>This specifies the alignment for a floating point type of a given bit
884 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
885 (double).</dd>
886 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
887 <dd>This specifies the alignment for an aggregate type of a given bit
888 <i>size</i>.</dd>
889</dl>
890<p>When constructing the data layout for a given target, LLVM starts with a
891default set of specifications which are then (possibly) overriden by the
892specifications in the <tt>datalayout</tt> keyword. The default specifications
893are given in this list:</p>
894<ul>
895 <li><tt>E</tt> - big endian</li>
896 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
897 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
898 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
899 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
900 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
901 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
902 alignment of 64-bits</li>
903 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
904 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
905 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
906 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
907 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
908</ul>
909<p>When llvm is determining the alignment for a given type, it uses the
910following rules:
911<ol>
912 <li>If the type sought is an exact match for one of the specifications, that
913 specification is used.</li>
914 <li>If no match is found, and the type sought is an integer type, then the
915 smallest integer type that is larger than the bitwidth of the sought type is
916 used. If none of the specifications are larger than the bitwidth then the the
917 largest integer type is used. For example, given the default specifications
918 above, the i7 type will use the alignment of i8 (next largest) while both
919 i65 and i256 will use the alignment of i64 (largest specified).</li>
920 <li>If no match is found, and the type sought is a vector type, then the
921 largest vector type that is smaller than the sought vector type will be used
922 as a fall back. This happens because <128 x double> can be implemented in
923 terms of 64 <2 x double>, for example.</li>
924</ol>
925</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]926
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]927<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]928<div class="doc_section"> <a name="typesystem">Type System</a> </div>
929<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]930
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]931<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]932
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]933<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]934intermediate representation. Being typed enables a number of
935optimizations to be performed on the IR directly, without having to do
936extra analyses on the side before the transformation. A strong type
937system makes it easier to read the generated code and enables novel
938analyses and transformations that are not feasible to perform on normal
939three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]940
941</div>
942
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]943<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]944<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]945<div class="doc_text">
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]946<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]947system. The current set of primitive types is as follows:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]948
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]949<table class="layout">
950 <tr class="layout">
951 <td class="left">
952 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]953 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]954 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]955 <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]956 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]957 </tbody>
958 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]959 </td>
960 <td class="right">
961 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]962 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]963 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]964 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]965 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]966 </tbody>
967 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]968 </td>
969 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]970</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]971</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]972
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]973<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]974<div class="doc_subsubsection"> <a name="t_classifications">Type
975Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]976<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]977<p>These different primitive types fall into a few useful
978classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]979
980<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]981 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]982 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]983 <tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]984 <td><a name="t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]985 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]986 </tr>
987 <tr>
988 <td><a name="t_floating">floating point</a></td>
989 <td><tt>float, double</tt></td>
990 </tr>
991 <tr>
992 <td><a name="t_firstclass">first class</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]993 <td><tt>i1, ..., float, double, <br/>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]994 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]995 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]996 </tr>
997 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]998</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]999
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1000<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1001most important. Values of these types are the only ones which can be
1002produced by instructions, passed as arguments, or used as operands to
1003instructions. This means that all structures and arrays must be
1004manipulated either by pointer or by component.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1005</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1006
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1007<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1008<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1009
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1010<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1011
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1012<p>The real power in LLVM comes from the derived types in the system.
1013This is what allows a programmer to represent arrays, functions,
1014pointers, and other useful types. Note that these derived types may be
1015recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1016
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1017</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1018
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1019<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1020<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1021
1022<div class="doc_text">
1023
1024<h5>Overview:</h5>
1025<p>The integer type is a very simple derived type that simply specifies an
1026arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10272^23-1 (about 8 million) can be specified.</p>
1028
1029<h5>Syntax:</h5>
1030
1031<pre>
1032 iN
1033</pre>
1034
1035<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1036value.</p>
1037
1038<h5>Examples:</h5>
1039<table class="layout">
1040 <tr class="layout">
1041 <td class="left">
1042 <tt>i1</tt><br/>
1043 <tt>i4</tt><br/>
1044 <tt>i8</tt><br/>
1045 <tt>i16</tt><br/>
1046 <tt>i32</tt><br/>
1047 <tt>i42</tt><br/>
1048 <tt>i64</tt><br/>
1049 <tt>i1942652</tt><br/>
1050 </td>
1051 <td class="left">
1052 A boolean integer of 1 bit<br/>
1053 A nibble sized integer of 4 bits.<br/>
1054 A byte sized integer of 8 bits.<br/>
1055 A half word sized integer of 16 bits.<br/>
1056 A word sized integer of 32 bits.<br/>
1057 An integer whose bit width is the answer. <br/>
1058 A double word sized integer of 64 bits.<br/>
1059 A really big integer of over 1 million bits.<br/>
1060 </td>
1061 </tr>
1062</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1063</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1064
1065<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1066<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1067
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1068<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1069
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1070<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1071
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1072<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1073sequentially in memory. The array type requires a size (number of
1074elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1075
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1076<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1077
1078<pre>
1079 [&lt;# elements&gt; x &lt;elementtype&gt;]
1080</pre>
1081
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1082<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1083be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1084
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1085<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1086<table class="layout">
1087 <tr class="layout">
1088 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1089 <tt>[40 x i32 ]</tt><br/>
1090 <tt>[41 x i32 ]</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1091 <tt>[40 x i8]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1092 </td>
1093 <td class="left">
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1094 Array of 40 32-bit integer values.<br/>
1095 Array of 41 32-bit integer values.<br/>
1096 Array of 40 8-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1097 </td>
1098 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1099</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1100<p>Here are some examples of multidimensional arrays:</p>
1101<table class="layout">
1102 <tr class="layout">
1103 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1104 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1105 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1106 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1107 </td>
1108 <td class="left">
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1109 3x4 array of 32-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1110 12x10 array of single precision floating point values.<br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1111 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1112 </td>
1113 </tr>
1114</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1115
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1116<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1117length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1118LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1119As a special case, however, zero length arrays are recognized to be variable
1120length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1121type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1122
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1123</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1124
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1125<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1126<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1127<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1128<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1129<p>The function type can be thought of as a function signature. It
1130consists of a return type and a list of formal parameter types.
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1131Function types are usually used to build virtual function tables
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1132(which are structures of pointers to functions), for indirect function
1133calls, and when defining a function.</p>
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1134<p>
1135The return type of a function type cannot be an aggregate type.
1136</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1137<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1138<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1139<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]1140specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1141which indicates that the function takes a variable number of arguments.
1142Variable argument functions can access their arguments with the <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1143 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1144<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1145<table class="layout">
1146 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1147 <td class="left"><tt>i32 (i32)</tt></td>
1148 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1149 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1150 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1151 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1152 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1153 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1154 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1155 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1156 <tt>float</tt>.
1157 </td>
1158 </tr><tr class="layout">
1159 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1160 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1161 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1162 which returns an integer. This is the signature for <tt>printf</tt> in
1163 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1164 </td>
1165 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1166</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1167
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1168</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1169<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1170<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1171<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1172<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1173<p>The structure type is used to represent a collection of data members
1174together in memory. The packing of the field types is defined to match
1175the ABI of the underlying processor. The elements of a structure may
1176be any type that has a size.</p>
1177<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1178and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1179field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1180instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1181<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1182<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1183<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1184<table class="layout">
1185 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1186 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1187 <td class="left">A triple of three <tt>i32</tt> values</td>
1188 </tr><tr class="layout">
1189 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1190 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1191 second element is a <a href="#t_pointer">pointer</a> to a
1192 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1193 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1194 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1195</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1196</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1198<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1199<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1200</div>
1201<div class="doc_text">
1202<h5>Overview:</h5>
1203<p>The packed structure type is used to represent a collection of data members
1204together in memory. There is no padding between fields. Further, the alignment
1205of a packed structure is 1 byte. The elements of a packed structure may
1206be any type that has a size.</p>
1207<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1208and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1209field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1210instruction.</p>
1211<h5>Syntax:</h5>
1212<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1213<h5>Examples:</h5>
1214<table class="layout">
1215 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1216 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1217 <td class="left">A triple of three <tt>i32</tt> values</td>
1218 </tr><tr class="layout">
1219 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1220 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1221 second element is a <a href="#t_pointer">pointer</a> to a
1222 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1223 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1224 </tr>
1225</table>
1226</div>
1227
1228<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1229<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1230<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1231<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1232<p>As in many languages, the pointer type represents a pointer or
1233reference to another object, which must live in memory.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1234<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1235<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1236<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1237<table class="layout">
1238 <tr class="layout">
1239 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1240 <tt>[4x i32]*</tt><br/>
1241 <tt>i32 (i32 *) *</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1242 </td>
1243 <td class="left">
1244 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]1245 four <tt>i32</tt> values<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1246 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1247 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1248 <tt>i32</tt>.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1249 </td>
1250 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1251</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1252</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1253
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1254<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1255<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1256<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1257
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1258<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1259
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1260<p>A vector type is a simple derived type that represents a vector
1261of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1262are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1263A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1264elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1265of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1266considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1267
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1268<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1269
1270<pre>
1271 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1272</pre>
1273
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1274<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1275be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1276
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1277<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1278
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1279<table class="layout">
1280 <tr class="layout">
1281 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1282 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1283 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1284 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1285 </td>
1286 <td class="left">
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1287 Vector of 4 32-bit integer values.<br/>
1288 Vector of 8 floating-point values.<br/>
1289 Vector of 2 64-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1290 </td>
1291 </tr>
1292</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1293</div>
1294
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1295<!-- _______________________________________________________________________ -->
1296<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1297<div class="doc_text">
1298
1299<h5>Overview:</h5>
1300
1301<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1302corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1303In LLVM, opaque types can eventually be resolved to any type (not just a
1304structure type).</p>
1305
1306<h5>Syntax:</h5>
1307
1308<pre>
1309 opaque
1310</pre>
1311
1312<h5>Examples:</h5>
1313
1314<table class="layout">
1315 <tr class="layout">
1316 <td class="left">
1317 <tt>opaque</tt>
1318 </td>
1319 <td class="left">
1320 An opaque type.<br/>
1321 </td>
1322 </tr>
1323</table>
1324</div>
1325
1326
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1327<!-- *********************************************************************** -->
1328<div class="doc_section"> <a name="constants">Constants</a> </div>
1329<!-- *********************************************************************** -->
1330
1331<div class="doc_text">
1332
1333<p>LLVM has several different basic types of constants. This section describes
1334them all and their syntax.</p>
1335
1336</div>
1337
1338<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1339<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1340
1341<div class="doc_text">
1342
1343<dl>
1344 <dt><b>Boolean constants</b></dt>
1345
1346 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1347 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1348 </dd>
1349
1350 <dt><b>Integer constants</b></dt>
1351
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1352 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1353 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1354 integer types.
1355 </dd>
1356
1357 <dt><b>Floating point constants</b></dt>
1358
1359 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1360 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1361 notation (see below). Floating point constants must have a <a
1362 href="#t_floating">floating point</a> type. </dd>
1363
1364 <dt><b>Null pointer constants</b></dt>
1365
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1366 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1367 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1368
1369</dl>
1370
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1371<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1372of floating point constants. For example, the form '<tt>double
13730x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13744.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1375(and the only time that they are generated by the disassembler) is when a
1376floating point constant must be emitted but it cannot be represented as a
1377decimal floating point number. For example, NaN's, infinities, and other
1378special values are represented in their IEEE hexadecimal format so that
1379assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1380
1381</div>
1382
1383<!-- ======================================================================= -->
1384<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1385</div>
1386
1387<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1388<p>Aggregate constants arise from aggregation of simple constants
1389and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1390
1391<dl>
1392 <dt><b>Structure constants</b></dt>
1393
1394 <dd>Structure constants are represented with notation similar to structure
1395 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1396 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner0a2d0992007-07-13 20:01:46 +0000[diff] [blame]1397 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]1398 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1399 types of elements must match those specified by the type.
1400 </dd>
1401
1402 <dt><b>Array constants</b></dt>
1403
1404 <dd>Array constants are represented with notation similar to array type
1405 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1406 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1407 constants must have <a href="#t_array">array type</a>, and the number and
1408 types of elements must match those specified by the type.
1409 </dd>
1410
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1411 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1412
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1413 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1414 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1415 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]1416 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1417 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1418 match those specified by the type.
1419 </dd>
1420
1421 <dt><b>Zero initialization</b></dt>
1422
1423 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1424 value to zero of <em>any</em> type, including scalar and aggregate types.
1425 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]1426 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1427 initializers.
1428 </dd>
1429</dl>
1430
1431</div>
1432
1433<!-- ======================================================================= -->
1434<div class="doc_subsection">
1435 <a name="globalconstants">Global Variable and Function Addresses</a>
1436</div>
1437
1438<div class="doc_text">
1439
1440<p>The addresses of <a href="#globalvars">global variables</a> and <a
1441href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1442constants. These constants are explicitly referenced when the <a
1443href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1444href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1445file:</p>
1446
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1447<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1448<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1449@X = global i32 17
1450@Y = global i32 42
1451@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1452</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1453</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1454
1455</div>
1456
1457<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1458<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1459<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1460 <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]1461 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1462 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1463
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1464 <p>Undefined values indicate to the compiler that the program is well defined
1465 no matter what value is used, giving the compiler more freedom to optimize.
1466 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1467</div>
1468
1469<!-- ======================================================================= -->
1470<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1471</div>
1472
1473<div class="doc_text">
1474
1475<p>Constant expressions are used to allow expressions involving other constants
1476to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1477href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1478that does not have side effects (e.g. load and call are not supported). The
1479following is the syntax for constant expressions:</p>
1480
1481<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1482 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1483 <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]1484 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1485
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1486 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1487 <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]1488 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]1489
1490 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1491 <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]1492 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]1493
1494 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1495 <dd>Truncate a floating point constant to another floating point type. The
1496 size of CST must be larger than the size of TYPE. Both types must be
1497 floating point.</dd>
1498
1499 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1500 <dd>Floating point extend a constant to another type. The size of CST must be
1501 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1502
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1503 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1504 <dd>Convert a floating point constant to the corresponding unsigned integer
1505 constant. TYPE must be an integer type. CST must be floating point. If the
1506 value won't fit in the integer type, the results are undefined.</dd>
1507
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1508 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1509 <dd>Convert a floating point constant to the corresponding signed integer
1510 constant. TYPE must be an integer type. CST must be floating point. If the
1511 value won't fit in the integer type, the results are undefined.</dd>
1512
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1513 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1514 <dd>Convert an unsigned integer constant to the corresponding floating point
1515 constant. TYPE must be floating point. CST must be of integer type. If the
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]1516 value won't fit in the floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1517
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1518 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1519 <dd>Convert a signed integer constant to the corresponding floating point
1520 constant. TYPE must be floating point. CST must be of integer type. If the
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]1521 value won't fit in the floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1522
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1523 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1524 <dd>Convert a pointer typed constant to the corresponding integer constant
1525 TYPE must be an integer type. CST must be of pointer type. The CST value is
1526 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1527
1528 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1529 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1530 pointer type. CST must be of integer type. The CST value is zero extended,
1531 truncated, or unchanged to make it fit in a pointer size. This one is
1532 <i>really</i> dangerous!</dd>
1533
1534 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1535 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1536 identical (same number of bits). The conversion is done as if the CST value
1537 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]1538 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1539 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]1540 pointers it is only valid to cast to another pointer type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1541 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1542
1543 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1544
1545 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1546 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1547 instruction, the index list may have zero or more indexes, which are required
1548 to make sense for the type of "CSTPTR".</dd>
1549
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1550 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1551
1552 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1553 constants.</dd>
1554
1555 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1556 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1557
1558 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1559 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1560
1561 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1562
1563 <dd>Perform the <a href="#i_extractelement">extractelement
1564 operation</a> on constants.
1565
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1566 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1567
1568 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1569 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1570
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1571
1572 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1573
1574 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1575 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1576
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1577 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1578
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1579 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1580 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1581 binary</a> operations. The constraints on operands are the same as those for
1582 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1583 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1584</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1585</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1586
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1587<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1588<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1589<!-- *********************************************************************** -->
1590
1591<!-- ======================================================================= -->
1592<div class="doc_subsection">
1593<a name="inlineasm">Inline Assembler Expressions</a>
1594</div>
1595
1596<div class="doc_text">
1597
1598<p>
1599LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1600Module-Level Inline Assembly</a>) through the use of a special value. This
1601value represents the inline assembler as a string (containing the instructions
1602to emit), a list of operand constraints (stored as a string), and a flag that
1603indicates whether or not the inline asm expression has side effects. An example
1604inline assembler expression is:
1605</p>
1606
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1607<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1608<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1609i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1610</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1611</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1612
1613<p>
1614Inline assembler expressions may <b>only</b> be used as the callee operand of
1615a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1616</p>
1617
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1618<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1619<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1620%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]1621</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1622</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1623
1624<p>
1625Inline asms with side effects not visible in the constraint list must be marked
1626as having side effects. This is done through the use of the
1627'<tt>sideeffect</tt>' keyword, like so:
1628</p>
1629
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1630<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1631<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1632call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1633</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1634</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1635
1636<p>TODO: The format of the asm and constraints string still need to be
1637documented here. Constraints on what can be done (e.g. duplication, moving, etc
1638need to be documented).
1639</p>
1640
1641</div>
1642
1643<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1644<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1645<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1646
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1647<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1648
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1649<p>The LLVM instruction set consists of several different
1650classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1651instructions</a>, <a href="#binaryops">binary instructions</a>,
1652<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1653 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1654instructions</a>.</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_subsection"> <a name="terminators">Terminator
1660Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1661
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1662<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1663
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1664<p>As mentioned <a href="#functionstructure">previously</a>, every
1665basic block in a program ends with a "Terminator" instruction, which
1666indicates which block should be executed after the current block is
1667finished. These terminator instructions typically yield a '<tt>void</tt>'
1668value: they produce control flow, not values (the one exception being
1669the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1670<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1671 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1672instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1673the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1674 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1675 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1676
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1677</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1678
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1679<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1680<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1681Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1682<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1683<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1684<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]1685 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1686</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1687<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1688<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1689value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1690<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1691returns a value and then causes control flow, and one that just causes
1692control flow to occur.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1693<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1694<p>The '<tt>ret</tt>' instruction may return any '<a
1695 href="#t_firstclass">first class</a>' type. Notice that a function is
1696not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1697instruction inside of the function that returns a value that does not
1698match the return type of the function.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1699<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1700<p>When the '<tt>ret</tt>' instruction is executed, control flow
1701returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1702 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1703the instruction after the call. If the caller was an "<a
1704 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1705at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1706returns a value, that value shall set the call or invoke instruction's
1707return value.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1708<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1709<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1710 ret void <i>; Return from a void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1711</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1712</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1713<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1714<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1715<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1716<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1717<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]1718</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1719<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1720<p>The '<tt>br</tt>' instruction is used to cause control flow to
1721transfer to a different basic block in the current function. There are
1722two forms of this instruction, corresponding to a conditional branch
1723and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1724<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1725<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1726single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1727unconditional form of the '<tt>br</tt>' instruction takes a single
1728'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1729<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1730<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1731argument is evaluated. If the value is <tt>true</tt>, control flows
1732to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1733control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1734<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1735<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]1736 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]1737</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1738<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1739<div class="doc_subsubsection">
1740 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1741</div>
1742
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1743<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1744<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1745
1746<pre>
1747 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1748</pre>
1749
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1750<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1751
1752<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1753several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1754instruction, allowing a branch to occur to one of many possible
1755destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1756
1757
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1758<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1759
1760<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1761comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1762an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1763table is not allowed to contain duplicate constant entries.</p>
1764
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1765<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1766
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1767<p>The <tt>switch</tt> instruction specifies a table of values and
1768destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1769table is searched for the given value. If the value is found, control flow is
1770transfered to the corresponding destination; otherwise, control flow is
1771transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1772
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1773<h5>Implementation:</h5>
1774
1775<p>Depending on properties of the target machine and the particular
1776<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1777ways. For example, it could be generated as a series of chained conditional
1778branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1779
1780<h5>Example:</h5>
1781
1782<pre>
1783 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1784 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1785 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1786
1787 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1788 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1789
1790 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1791 switch i32 %val, label %otherwise [ i32 0, label %onzero
1792 i32 1, label %onone
1793 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1794</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1795</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1796
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1797<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1798<div class="doc_subsubsection">
1799 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1800</div>
1801
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1802<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1803
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1804<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1805
1806<pre>
1807 &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]1808 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1809</pre>
1810
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]1811<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1812
1813<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1814function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1815'<tt>normal</tt>' label or the
1816'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1817"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1818"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1819href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1820continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1821
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1822<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1823
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1824<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1825
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1826<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1827 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]1828 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1829 convention</a> the call should use. If none is specified, the call defaults
1830 to using C calling conventions.
1831 </li>
1832 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1833 function value being invoked. In most cases, this is a direct function
1834 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1835 an arbitrary pointer to function value.
1836 </li>
1837
1838 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1839 function to be invoked. </li>
1840
1841 <li>'<tt>function args</tt>': argument list whose types match the function
1842 signature argument types. If the function signature indicates the function
1843 accepts a variable number of arguments, the extra arguments can be
1844 specified. </li>
1845
1846 <li>'<tt>normal label</tt>': the label reached when the called function
1847 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1848
1849 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1850 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1851
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1852</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1853
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1854<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1855
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1856<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1857href="#i_call">call</a></tt>' instruction in most regards. The primary
1858difference is that it establishes an association with a label, which is used by
1859the runtime library to unwind the stack.</p>
1860
1861<p>This instruction is used in languages with destructors to ensure that proper
1862cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1863exception. Additionally, this is important for implementation of
1864'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1865
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1866<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1867<pre>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1868 %retval = invoke i32 %Test(i32 15) to label %Continue
1869 unwind label %TestCleanup <i>; {i32}:retval set</i>
1870 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1871 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1872</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1873</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1874
1875
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1876<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1877
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1878<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1879Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1880
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1881<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1882
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1883<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1884<pre>
1885 unwind
1886</pre>
1887
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1888<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1889
1890<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1891at the first callee in the dynamic call stack which used an <a
1892href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1893primarily used to implement exception handling.</p>
1894
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1895<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1896
1897<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1898immediately halt. The dynamic call stack is then searched for the first <a
1899href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1900execution continues at the "exceptional" destination block specified by the
1901<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1902dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1903</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1904
1905<!-- _______________________________________________________________________ -->
1906
1907<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1908Instruction</a> </div>
1909
1910<div class="doc_text">
1911
1912<h5>Syntax:</h5>
1913<pre>
1914 unreachable
1915</pre>
1916
1917<h5>Overview:</h5>
1918
1919<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1920instruction is used to inform the optimizer that a particular portion of the
1921code is not reachable. This can be used to indicate that the code after a
1922no-return function cannot be reached, and other facts.</p>
1923
1924<h5>Semantics:</h5>
1925
1926<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1927</div>
1928
1929
1930
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1931<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1932<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1933<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1934<p>Binary operators are used to do most of the computation in a
1935program. They require two operands, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1936produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1937multiple 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]1938The result value of a binary operator is not
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1939necessarily the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1940<p>There are several different binary operators:</p>
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_add">'<tt>add</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; = 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]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>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1951<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1952<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1953 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1954 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]1955Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1956<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1957<p>The value produced is the integer or floating point sum of the two
1958operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1959<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1960<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]1961</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1962</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1963<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1964<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1965Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1966<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1967<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1968<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]1969</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1970<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1971<p>The '<tt>sub</tt>' instruction returns the difference of its two
1972operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1973<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
1974instruction present in most other intermediate representations.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1975<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1976<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1977 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1978values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1979This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1980Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1981<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1982<p>The value produced is the integer or floating point difference of
1983the two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]1985<pre>
1986 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1987 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1988</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1989</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1990<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1991<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
1992Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1993<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1994<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1995<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]1996</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1997<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1998<p>The '<tt>mul</tt>' instruction returns the product of its two
1999operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2000<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2001<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2002 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2003values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2004This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2005Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2006<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2007<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2008two operands.</p>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]2009<p>Because the operands are the same width, the result of an integer
2010multiplication is the same whether the operands should be deemed unsigned or
2011signed.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2012<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2013<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]2014</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2015</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2016<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2017<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2018</a></div>
2019<div class="doc_text">
2020<h5>Syntax:</h5>
2021<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2022</pre>
2023<h5>Overview:</h5>
2024<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2025operands.</p>
2026<h5>Arguments:</h5>
2027<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2028<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2029types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2030of the values in which case the elements must be integers.</p>
2031<h5>Semantics:</h5>
2032<p>The value produced is the unsigned integer quotient of the two operands. This
2033instruction always performs an unsigned division operation, regardless of
2034whether the arguments are unsigned or not.</p>
2035<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2036<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]2037</pre>
2038</div>
2039<!-- _______________________________________________________________________ -->
2040<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2041</a> </div>
2042<div class="doc_text">
2043<h5>Syntax:</h5>
2044<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2045</pre>
2046<h5>Overview:</h5>
2047<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2048operands.</p>
2049<h5>Arguments:</h5>
2050<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2051<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2052types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2053of the values in which case the elements must be integers.</p>
2054<h5>Semantics:</h5>
2055<p>The value produced is the signed integer quotient of the two operands. This
2056instruction always performs a signed division operation, regardless of whether
2057the arguments are signed or not.</p>
2058<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2059<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]2060</pre>
2061</div>
2062<!-- _______________________________________________________________________ -->
2063<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2064Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2065<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2066<h5>Syntax:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2067<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]2068</pre>
2069<h5>Overview:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2070<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2071operands.</p>
2072<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2073<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2074<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2075identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2076versions of floating point values.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2077<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2078<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2079<h5>Example:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2080<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]2081</pre>
2082</div>
2083<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2084<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2085</div>
2086<div class="doc_text">
2087<h5>Syntax:</h5>
2088<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2089</pre>
2090<h5>Overview:</h5>
2091<p>The '<tt>urem</tt>' instruction returns the remainder from the
2092unsigned division of its two arguments.</p>
2093<h5>Arguments:</h5>
2094<p>The two arguments to the '<tt>urem</tt>' instruction must be
2095<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame^]2096types. This instruction can also take <a href="#t_vector">vector</a> versions
2097of the values in which case the elements must be integers.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2098<h5>Semantics:</h5>
2099<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2100This instruction always performs an unsigned division to get the remainder,
2101regardless of whether the arguments are unsigned or not.</p>
2102<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2103<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]2104</pre>
2105
2106</div>
2107<!-- _______________________________________________________________________ -->
2108<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2109Instruction</a> </div>
2110<div class="doc_text">
2111<h5>Syntax:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2112<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]2113</pre>
2114<h5>Overview:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2115<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame^]2116signed division of its two operands. This instruction can also take
2117<a href="#t_vector">vector</a> versions of the values in which case
2118the elements must be integers.</p>
2119</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2120<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2121<p>The two arguments to the '<tt>srem</tt>' instruction must be
2122<a href="#t_integer">integer</a> values. Both arguments must have identical
2123types.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2124<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2125<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2126has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2127operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2128a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2129 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2130Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2131please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2132Wikipedia: modulo operation</a>.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2133<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2134<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]2135</pre>
2136
2137</div>
2138<!-- _______________________________________________________________________ -->
2139<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2140Instruction</a> </div>
2141<div class="doc_text">
2142<h5>Syntax:</h5>
2143<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2144</pre>
2145<h5>Overview:</h5>
2146<p>The '<tt>frem</tt>' instruction returns the remainder from the
2147division of its two operands.</p>
2148<h5>Arguments:</h5>
2149<p>The two arguments to the '<tt>frem</tt>' instruction must be
2150<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame^]2151identical types. This instruction can also take <a href="#t_vector">vector</a>
2152versions of floating point values.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2153<h5>Semantics:</h5>
2154<p>This instruction returns the <i>remainder</i> of a division.</p>
2155<h5>Example:</h5>
2156<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]2157</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2158</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2159
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2160<!-- ======================================================================= -->
2161<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2162Operations</a> </div>
2163<div class="doc_text">
2164<p>Bitwise binary operators are used to do various forms of
2165bit-twiddling in a program. They are generally very efficient
2166instructions and can commonly be strength reduced from other
2167instructions. They require two operands, execute an operation on them,
2168and produce a single value. The resulting value of the bitwise binary
2169operators is always the same type as its first operand.</p>
2170</div>
2171
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2172<!-- _______________________________________________________________________ -->
2173<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2174Instruction</a> </div>
2175<div class="doc_text">
2176<h5>Syntax:</h5>
2177<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2178</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2179
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2180<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2181
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2182<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2183the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2184
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2185<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2186
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2187<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2188 href="#t_integer">integer</a> type.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2189
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2190<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2191
2192<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2193<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2194of bits in <tt>var1</tt>, the result is undefined.</p>
2195
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2196<h5>Example:</h5><pre>
2197 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2198 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2199 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2200 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2201</pre>
2202</div>
2203<!-- _______________________________________________________________________ -->
2204<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2205Instruction</a> </div>
2206<div class="doc_text">
2207<h5>Syntax:</h5>
2208<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2209</pre>
2210
2211<h5>Overview:</h5>
2212<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2213operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2214
2215<h5>Arguments:</h5>
2216<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2217<a href="#t_integer">integer</a> type.</p>
2218
2219<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2220
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2221<p>This instruction always performs a logical shift right operation. The most
2222significant bits of the result will be filled with zero bits after the
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2223shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2224the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2225
2226<h5>Example:</h5>
2227<pre>
2228 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2229 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2230 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2231 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2232 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2233</pre>
2234</div>
2235
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2236<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2237<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2238Instruction</a> </div>
2239<div class="doc_text">
2240
2241<h5>Syntax:</h5>
2242<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2243</pre>
2244
2245<h5>Overview:</h5>
2246<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2247operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2248
2249<h5>Arguments:</h5>
2250<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2251<a href="#t_integer">integer</a> type.</p>
2252
2253<h5>Semantics:</h5>
2254<p>This instruction always performs an arithmetic shift right operation,
2255The most significant bits of the result will be filled with the sign bit
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2256of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2257larger than the number of bits in <tt>var1</tt>, the result is undefined.
2258</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2259
2260<h5>Example:</h5>
2261<pre>
2262 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2263 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2264 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2265 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2266 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2267</pre>
2268</div>
2269
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2270<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2271<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2272Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2273<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2274<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2275<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]2276</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2277<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2278<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2279its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2280<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2281<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2282 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2283identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2284<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2285<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2286<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2287<div style="align: center">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2288<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2289 <tbody>
2290 <tr>
2291 <td>In0</td>
2292 <td>In1</td>
2293 <td>Out</td>
2294 </tr>
2295 <tr>
2296 <td>0</td>
2297 <td>0</td>
2298 <td>0</td>
2299 </tr>
2300 <tr>
2301 <td>0</td>
2302 <td>1</td>
2303 <td>0</td>
2304 </tr>
2305 <tr>
2306 <td>1</td>
2307 <td>0</td>
2308 <td>0</td>
2309 </tr>
2310 <tr>
2311 <td>1</td>
2312 <td>1</td>
2313 <td>1</td>
2314 </tr>
2315 </tbody>
2316</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2317</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2318<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2319<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2320 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2321 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2322</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2323</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2324<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2325<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2326<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2327<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2328<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]2329</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2330<h5>Overview:</h5>
2331<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2332or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2333<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2334<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2335 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2336identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2337<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2338<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2339<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2340<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2341<table border="1" cellspacing="0" cellpadding="4">
2342 <tbody>
2343 <tr>
2344 <td>In0</td>
2345 <td>In1</td>
2346 <td>Out</td>
2347 </tr>
2348 <tr>
2349 <td>0</td>
2350 <td>0</td>
2351 <td>0</td>
2352 </tr>
2353 <tr>
2354 <td>0</td>
2355 <td>1</td>
2356 <td>1</td>
2357 </tr>
2358 <tr>
2359 <td>1</td>
2360 <td>0</td>
2361 <td>1</td>
2362 </tr>
2363 <tr>
2364 <td>1</td>
2365 <td>1</td>
2366 <td>1</td>
2367 </tr>
2368 </tbody>
2369</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2370</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2371<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2372<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2373 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2374 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2375</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2376</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2377<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2378<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2379Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2380<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2381<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2382<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]2383</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2384<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2385<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2386or of its two operands. The <tt>xor</tt> is used to implement the
2387"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2388<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2389<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2390 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2391identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2392<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2393<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2394<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2395<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2396<table border="1" cellspacing="0" cellpadding="4">
2397 <tbody>
2398 <tr>
2399 <td>In0</td>
2400 <td>In1</td>
2401 <td>Out</td>
2402 </tr>
2403 <tr>
2404 <td>0</td>
2405 <td>0</td>
2406 <td>0</td>
2407 </tr>
2408 <tr>
2409 <td>0</td>
2410 <td>1</td>
2411 <td>1</td>
2412 </tr>
2413 <tr>
2414 <td>1</td>
2415 <td>0</td>
2416 <td>1</td>
2417 </tr>
2418 <tr>
2419 <td>1</td>
2420 <td>1</td>
2421 <td>0</td>
2422 </tr>
2423 </tbody>
2424</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2425</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2426<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2427<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2428<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2429 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2430 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2431 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2432</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2433</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2434
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2435<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2436<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2437 <a name="vectorops">Vector Operations</a>
2438</div>
2439
2440<div class="doc_text">
2441
2442<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2443target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2444vector-specific operations needed to process vectors effectively. While LLVM
2445does directly support these vector operations, many sophisticated algorithms
2446will want to use target-specific intrinsics to take full advantage of a specific
2447target.</p>
2448
2449</div>
2450
2451<!-- _______________________________________________________________________ -->
2452<div class="doc_subsubsection">
2453 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2454</div>
2455
2456<div class="doc_text">
2457
2458<h5>Syntax:</h5>
2459
2460<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2461 &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]2462</pre>
2463
2464<h5>Overview:</h5>
2465
2466<p>
2467The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2468element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2469</p>
2470
2471
2472<h5>Arguments:</h5>
2473
2474<p>
2475The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2476value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2477an index indicating the position from which to extract the element.
2478The index may be a variable.</p>
2479
2480<h5>Semantics:</h5>
2481
2482<p>
2483The result is a scalar of the same type as the element type of
2484<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2485<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2486results are undefined.
2487</p>
2488
2489<h5>Example:</h5>
2490
2491<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2492 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2493</pre>
2494</div>
2495
2496
2497<!-- _______________________________________________________________________ -->
2498<div class="doc_subsubsection">
2499 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2500</div>
2501
2502<div class="doc_text">
2503
2504<h5>Syntax:</h5>
2505
2506<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2507 &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]2508</pre>
2509
2510<h5>Overview:</h5>
2511
2512<p>
2513The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2514element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2515</p>
2516
2517
2518<h5>Arguments:</h5>
2519
2520<p>
2521The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2522value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2523scalar value whose type must equal the element type of the first
2524operand. The third operand is an index indicating the position at
2525which to insert the value. The index may be a variable.</p>
2526
2527<h5>Semantics:</h5>
2528
2529<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2530The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2531element values are those of <tt>val</tt> except at position
2532<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2533exceeds the length of <tt>val</tt>, the results are undefined.
2534</p>
2535
2536<h5>Example:</h5>
2537
2538<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2539 %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]2540</pre>
2541</div>
2542
2543<!-- _______________________________________________________________________ -->
2544<div class="doc_subsubsection">
2545 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2546</div>
2547
2548<div class="doc_text">
2549
2550<h5>Syntax:</h5>
2551
2552<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2553 &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]2554</pre>
2555
2556<h5>Overview:</h5>
2557
2558<p>
2559The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2560from two input vectors, returning a vector of the same type.
2561</p>
2562
2563<h5>Arguments:</h5>
2564
2565<p>
2566The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2567with types that match each other and types that match the result of the
2568instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2569of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2570</p>
2571
2572<p>
2573The shuffle mask operand is required to be a constant vector with either
2574constant integer or undef values.
2575</p>
2576
2577<h5>Semantics:</h5>
2578
2579<p>
2580The elements of the two input vectors are numbered from left to right across
2581both of the vectors. The shuffle mask operand specifies, for each element of
2582the result vector, which element of the two input registers the result element
2583gets. The element selector may be undef (meaning "don't care") and the second
2584operand may be undef if performing a shuffle from only one vector.
2585</p>
2586
2587<h5>Example:</h5>
2588
2589<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2590 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2591 &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]2592 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2593 &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]2594</pre>
2595</div>
2596
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2597
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2598<!-- ======================================================================= -->
2599<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2600 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2601</div>
2602
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2603<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2604
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2605<p>A key design point of an SSA-based representation is how it
2606represents memory. In LLVM, no memory locations are in SSA form, which
2607makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2608allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2609
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2610</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2611
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2612<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2613<div class="doc_subsubsection">
2614 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2615</div>
2616
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2617<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2618
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2619<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2620
2621<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2622 &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]2623</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2624
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2625<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2626
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2627<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2628heap and returns a pointer to it.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2629
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2630<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2631
2632<p>The '<tt>malloc</tt>' instruction allocates
2633<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]2634bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2635appropriate type to the program. If "NumElements" is specified, it is the
2636number of elements allocated. If an alignment is specified, the value result
2637of the allocation is guaranteed to be aligned to at least that boundary. If
2638not specified, or if zero, the target can choose to align the allocation on any
2639convenient boundary.</p>
2640
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2641<p>'<tt>type</tt>' must be a sized type.</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
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2645<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2646a pointer is returned.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2647
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2648<h5>Example:</h5>
2649
2650<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2651 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2652
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2653 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2654 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2655 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2656 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2657 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2658</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2659</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2660
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2661<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2662<div class="doc_subsubsection">
2663 <a name="i_free">'<tt>free</tt>' Instruction</a>
2664</div>
2665
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2666<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2667
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2668<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2669
2670<pre>
2671 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2672</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2673
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2674<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2675
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2676<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2677memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2678
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2679<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2680
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2681<p>'<tt>value</tt>' shall be a pointer value that points to a value
2682that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2683instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2684
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2685<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2686
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2687<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2688after this instruction executes.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2689
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2690<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2691
2692<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2693 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2694 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2695</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2696</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2697
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2698<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2699<div class="doc_subsubsection">
2700 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2701</div>
2702
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2703<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2704
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2705<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2706
2707<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2708 &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]2709</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2710
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2711<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2712
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2713<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2714currently executing function, to be automatically released when this function
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2715returns to its caller.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2716
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2717<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2718
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2719<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2720bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2721appropriate type to the program. If "NumElements" is specified, it is the
2722number of elements allocated. If an alignment is specified, the value result
2723of the allocation is guaranteed to be aligned to at least that boundary. If
2724not specified, or if zero, the target can choose to align the allocation on any
2725convenient boundary.</p>
2726
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2727<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2729<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2730
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2731<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2732memory is automatically released when the function returns. The '<tt>alloca</tt>'
2733instruction is commonly used to represent automatic variables that must
2734have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]2735 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]2736instructions), the memory is reclaimed.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2737
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2738<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2739
2740<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2741 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2742 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2743 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2744 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2745</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2746</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2747
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2748<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2749<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2750Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2751<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2752<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2753<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]2754<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2755<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2756<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2757<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2758address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]2759 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2760marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2761the number or order of execution of this <tt>load</tt> with other
2762volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2763instructions. </p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2764<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2765<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2766<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2767<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2768 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2769 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2770 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2771</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2772</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2773<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2774<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2775Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]2776<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2777<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2778<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2779 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]2780</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2781<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2782<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2783<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2784<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2785to 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]2786operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2787operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2788optimizer is not allowed to modify the number or order of execution of
2789this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2790 href="#i_store">store</a></tt> instructions.</p>
2791<h5>Semantics:</h5>
2792<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2793at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2794<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2795<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]2796 store i32 3, i32* %ptr <i>; yields {void}</i>
2797 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2798</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2799</div>
2800
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2801<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2802<div class="doc_subsubsection">
2803 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2804</div>
2805
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2806<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2807<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2808<pre>
2809 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2810</pre>
2811
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2812<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2813
2814<p>
2815The '<tt>getelementptr</tt>' instruction is used to get the address of a
2816subelement of an aggregate data structure.</p>
2817
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2818<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2819
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2820<p>This instruction takes a list of integer operands that indicate what
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2821elements of the aggregate object to index to. The actual types of the arguments
2822provided depend on the type of the first pointer argument. The
2823'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]2824levels 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]2825structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2826into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2827be sign extended to 64-bit values.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2828
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2829<p>For example, let's consider a C code fragment and how it gets
2830compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2831
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2832<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2833<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2834struct RT {
2835 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2836 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2837 char C;
2838};
2839struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2840 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2841 double Y;
2842 struct RT Z;
2843};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2844
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2845int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2846 return &amp;s[1].Z.B[5][13];
2847}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2848</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2849</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2850
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2851<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2852
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2853<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2854<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2855%RT = type { i8 , [10 x [20 x i32]], i8 }
2856%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2857
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2858define i32* %foo(%ST* %s) {
2859entry:
2860 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2861 ret i32* %reg
2862}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2863</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2864</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2865
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2866<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2867
2868<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2869on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2870and <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]2871<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]2872to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]2873<b>constants</b>.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2874
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2875<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]2876type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2877}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2878the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2879i8 }</tt>' type, another structure. The third index indexes into the second
2880element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2881array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2882'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2883to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2884
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2885<p>Note that it is perfectly legal to index partially through a
2886structure, returning a pointer to an inner element. Because of this,
2887the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2888
2889<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2890 define i32* %foo(%ST* %s) {
2891 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2892 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2893 %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]2894 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2895 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2896 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2897 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2898</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2899
2900<p>Note that it is undefined to access an array out of bounds: array and
2901pointer indexes must always be within the defined bounds of the array type.
2902The one exception for this rules is zero length arrays. These arrays are
2903defined to be accessible as variable length arrays, which requires access
2904beyond the zero'th element.</p>
2905
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2906<p>The getelementptr instruction is often confusing. For some more insight
2907into how it works, see <a href="GetElementPtr.html">the getelementptr
2908FAQ</a>.</p>
2909
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2910<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2911
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2912<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2913 <i>; yields [12 x i8]*:aptr</i>
2914 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2915</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2916</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2917
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2918<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2919<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2920</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2921<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2922<p>The instructions in this category are the conversion instructions (casting)
2923which all take a single operand and a type. They perform various bit conversions
2924on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2925</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2926
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2927<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2928<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2929 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2930</div>
2931<div class="doc_text">
2932
2933<h5>Syntax:</h5>
2934<pre>
2935 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2936</pre>
2937
2938<h5>Overview:</h5>
2939<p>
2940The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2941</p>
2942
2943<h5>Arguments:</h5>
2944<p>
2945The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2946be 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]2947and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2948type. The bit size of <tt>value</tt> must be larger than the bit size of
2949<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2950
2951<h5>Semantics:</h5>
2952<p>
2953The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2954and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2955larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2956It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2957
2958<h5>Example:</h5>
2959<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2960 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2961 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2962 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2963</pre>
2964</div>
2965
2966<!-- _______________________________________________________________________ -->
2967<div class="doc_subsubsection">
2968 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
2969</div>
2970<div class="doc_text">
2971
2972<h5>Syntax:</h5>
2973<pre>
2974 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2975</pre>
2976
2977<h5>Overview:</h5>
2978<p>The '<tt>zext</tt>' instruction zero extends its operand to type
2979<tt>ty2</tt>.</p>
2980
2981
2982<h5>Arguments:</h5>
2983<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]2984<a href="#t_integer">integer</a> type, and a type to cast it to, which must
2985also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2986<tt>value</tt> must be smaller than the bit size of the destination type,
2987<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2988
2989<h5>Semantics:</h5>
2990<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]2991bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2992
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]2993<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]2994
2995<h5>Example:</h5>
2996<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2997 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2998 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2999</pre>
3000</div>
3001
3002<!-- _______________________________________________________________________ -->
3003<div class="doc_subsubsection">
3004 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3005</div>
3006<div class="doc_text">
3007
3008<h5>Syntax:</h5>
3009<pre>
3010 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3011</pre>
3012
3013<h5>Overview:</h5>
3014<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3015
3016<h5>Arguments:</h5>
3017<p>
3018The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3019<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3020also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3021<tt>value</tt> must be smaller than the bit size of the destination type,
3022<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3023
3024<h5>Semantics:</h5>
3025<p>
3026The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3027bit (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]3028the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3029
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3030<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]3031
3032<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3033<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3034 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3035 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3036</pre>
3037</div>
3038
3039<!-- _______________________________________________________________________ -->
3040<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3041 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3042</div>
3043
3044<div class="doc_text">
3045
3046<h5>Syntax:</h5>
3047
3048<pre>
3049 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3050</pre>
3051
3052<h5>Overview:</h5>
3053<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3054<tt>ty2</tt>.</p>
3055
3056
3057<h5>Arguments:</h5>
3058<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3059 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3060cast it to. The size of <tt>value</tt> must be larger than the size of
3061<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3062<i>no-op cast</i>.</p>
3063
3064<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3065<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3066<a href="#t_floating">floating point</a> type to a smaller
3067<a href="#t_floating">floating point</a> type. If the value cannot fit within
3068the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3069
3070<h5>Example:</h5>
3071<pre>
3072 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3073 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3074</pre>
3075</div>
3076
3077<!-- _______________________________________________________________________ -->
3078<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3079 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3080</div>
3081<div class="doc_text">
3082
3083<h5>Syntax:</h5>
3084<pre>
3085 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3086</pre>
3087
3088<h5>Overview:</h5>
3089<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3090floating point value.</p>
3091
3092<h5>Arguments:</h5>
3093<p>The '<tt>fpext</tt>' instruction takes a
3094<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3095and a <a href="#t_floating">floating point</a> type to cast it to. The source
3096type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3097
3098<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3099<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3100<a href="#t_floating">floating point</a> type to a larger
3101<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3102used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3103<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]3104
3105<h5>Example:</h5>
3106<pre>
3107 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3108 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3109</pre>
3110</div>
3111
3112<!-- _______________________________________________________________________ -->
3113<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3114 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3115</div>
3116<div class="doc_text">
3117
3118<h5>Syntax:</h5>
3119<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3120 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3121</pre>
3122
3123<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3124<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3125unsigned integer equivalent of type <tt>ty2</tt>.
3126</p>
3127
3128<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3129<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3130<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]3131must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3132
3133<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3134<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3135<a href="#t_floating">floating point</a> operand into the nearest (rounding
3136towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3137the results are undefined.</p>
3138
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3139<h5>Example:</h5>
3140<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3141 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3142 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3143 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3144</pre>
3145</div>
3146
3147<!-- _______________________________________________________________________ -->
3148<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3149 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3150</div>
3151<div class="doc_text">
3152
3153<h5>Syntax:</h5>
3154<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3155 &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]3156</pre>
3157
3158<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3159<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3160<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]3161</p>
3162
3163
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3164<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3165<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]3166<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]3167must also be an <a href="#t_integer">integer</a> type.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3168
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3169<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3170<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3171<a href="#t_floating">floating point</a> operand into the nearest (rounding
3172towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3173the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3174
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3175<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3176<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3177 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3178 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3179 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3180</pre>
3181</div>
3182
3183<!-- _______________________________________________________________________ -->
3184<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3185 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3186</div>
3187<div class="doc_text">
3188
3189<h5>Syntax:</h5>
3190<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3191 &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]3192</pre>
3193
3194<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3195<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3196integer and converts that value to the <tt>ty2</tt> type.</p>
3197
3198
3199<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3200<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]3201<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]3202be a <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>uitofp</tt>' instruction interprets its operand as an unsigned
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
3210<h5>Example:</h5>
3211<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3212 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3213 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3214</pre>
3215</div>
3216
3217<!-- _______________________________________________________________________ -->
3218<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3219 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3220</div>
3221<div class="doc_text">
3222
3223<h5>Syntax:</h5>
3224<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3225 &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]3226</pre>
3227
3228<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3229<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3230integer and converts that value to the <tt>ty2</tt> type.</p>
3231
3232<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3233<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]3234<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]3235a <a href="#t_floating">floating point</a> type.</p>
3236
3237<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3238<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3239integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3240the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3241
3242<h5>Example:</h5>
3243<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3244 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3245 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3246</pre>
3247</div>
3248
3249<!-- _______________________________________________________________________ -->
3250<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3251 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3252</div>
3253<div class="doc_text">
3254
3255<h5>Syntax:</h5>
3256<pre>
3257 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3258</pre>
3259
3260<h5>Overview:</h5>
3261<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3262the integer type <tt>ty2</tt>.</p>
3263
3264<h5>Arguments:</h5>
3265<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3266must 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]3267<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3268
3269<h5>Semantics:</h5>
3270<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3271<tt>ty2</tt> by interpreting the pointer value as an integer and either
3272truncating or zero extending that value to the size of the integer type. If
3273<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3274<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]3275are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3276change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3277
3278<h5>Example:</h5>
3279<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3280 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3281 %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]3282</pre>
3283</div>
3284
3285<!-- _______________________________________________________________________ -->
3286<div class="doc_subsubsection">
3287 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3288</div>
3289<div class="doc_text">
3290
3291<h5>Syntax:</h5>
3292<pre>
3293 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3294</pre>
3295
3296<h5>Overview:</h5>
3297<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3298a pointer type, <tt>ty2</tt>.</p>
3299
3300<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3301<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3302value to cast, and a type to cast it to, which must be a
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]3303<a href="#t_pointer">pointer</a> type.
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3304
3305<h5>Semantics:</h5>
3306<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3307<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3308the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3309size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3310the size of a pointer then a zero extension is done. If they are the same size,
3311nothing is done (<i>no-op cast</i>).</p>
3312
3313<h5>Example:</h5>
3314<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3315 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3316 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3317 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3318</pre>
3319</div>
3320
3321<!-- _______________________________________________________________________ -->
3322<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3323 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3324</div>
3325<div class="doc_text">
3326
3327<h5>Syntax:</h5>
3328<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3329 &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]3330</pre>
3331
3332<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3333<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3334<tt>ty2</tt> without changing any bits.</p>
3335
3336<h5>Arguments:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3337<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3338a first class value, and a type to cast it to, which must also be a <a
3339 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3340and the destination type, <tt>ty2</tt>, must be identical. If the source
3341type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3342
3343<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3344<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3345<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3346this conversion. The conversion is done as if the <tt>value</tt> had been
3347stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3348converted to other pointer types with this instruction. To convert pointers to
3349other types, use the <a href="#i_inttoptr">inttoptr</a> or
3350<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3351
3352<h5>Example:</h5>
3353<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3354 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3355 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3356 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3357</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3358</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3359
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3360<!-- ======================================================================= -->
3361<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3362<div class="doc_text">
3363<p>The instructions in this category are the "miscellaneous"
3364instructions, which defy better classification.</p>
3365</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3366
3367<!-- _______________________________________________________________________ -->
3368<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3369</div>
3370<div class="doc_text">
3371<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3372<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]3373</pre>
3374<h5>Overview:</h5>
3375<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3376of its two integer operands.</p>
3377<h5>Arguments:</h5>
3378<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3379the condition code indicating the kind of comparison to perform. It is not
3380a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3381<ol>
3382 <li><tt>eq</tt>: equal</li>
3383 <li><tt>ne</tt>: not equal </li>
3384 <li><tt>ugt</tt>: unsigned greater than</li>
3385 <li><tt>uge</tt>: unsigned greater or equal</li>
3386 <li><tt>ult</tt>: unsigned less than</li>
3387 <li><tt>ule</tt>: unsigned less or equal</li>
3388 <li><tt>sgt</tt>: signed greater than</li>
3389 <li><tt>sge</tt>: signed greater or equal</li>
3390 <li><tt>slt</tt>: signed less than</li>
3391 <li><tt>sle</tt>: signed less or equal</li>
3392</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3393<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3394<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3395<h5>Semantics:</h5>
3396<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3397the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3398yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3399<ol>
3400 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3401 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3402 </li>
3403 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3404 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3405 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3406 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3407 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3408 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3409 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3410 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3411 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3412 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3413 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3414 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3415 <li><tt>sge</tt>: interprets the operands as signed values and yields
3416 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3417 <li><tt>slt</tt>: interprets the operands as signed values and yields
3418 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3419 <li><tt>sle</tt>: interprets the operands as signed values and yields
3420 <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]3421</ol>
3422<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3423values are compared as if they were integers.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3424
3425<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3426<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3427 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3428 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3429 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3430 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3431 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3432</pre>
3433</div>
3434
3435<!-- _______________________________________________________________________ -->
3436<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3437</div>
3438<div class="doc_text">
3439<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3440<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]3441</pre>
3442<h5>Overview:</h5>
3443<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3444of its floating point operands.</p>
3445<h5>Arguments:</h5>
3446<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3447the condition code indicating the kind of comparison to perform. It is not
3448a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3449<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3450 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3451 <li><tt>oeq</tt>: ordered and equal</li>
3452 <li><tt>ogt</tt>: ordered and greater than </li>
3453 <li><tt>oge</tt>: ordered and greater than or equal</li>
3454 <li><tt>olt</tt>: ordered and less than </li>
3455 <li><tt>ole</tt>: ordered and less than or equal</li>
3456 <li><tt>one</tt>: ordered and not equal</li>
3457 <li><tt>ord</tt>: ordered (no nans)</li>
3458 <li><tt>ueq</tt>: unordered or equal</li>
3459 <li><tt>ugt</tt>: unordered or greater than </li>
3460 <li><tt>uge</tt>: unordered or greater than or equal</li>
3461 <li><tt>ult</tt>: unordered or less than </li>
3462 <li><tt>ule</tt>: unordered or less than or equal</li>
3463 <li><tt>une</tt>: unordered or not equal</li>
3464 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3465 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3466</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3467<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]3468<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3469<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3470<a href="#t_floating">floating point</a> typed. They must have identical
3471types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3472<h5>Semantics:</h5>
3473<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3474the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3475yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3476<ol>
3477 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3478 <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]3479 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3480 <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]3481 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3482 <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]3483 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3484 <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]3485 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3486 <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]3487 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3488 <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]3489 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3490 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3491 <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]3492 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3493 <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]3494 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3495 <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]3496 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3497 <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]3498 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3499 <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]3500 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3501 <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]3502 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3503 <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]3504 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3505</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3506
3507<h5>Example:</h5>
3508<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3509 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3510 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3511 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3512</pre>
3513</div>
3514
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3515<!-- _______________________________________________________________________ -->
3516<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3517Instruction</a> </div>
3518<div class="doc_text">
3519<h5>Syntax:</h5>
3520<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3521<h5>Overview:</h5>
3522<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3523the SSA graph representing the function.</p>
3524<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3525<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3526field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3527as arguments, with one pair for each predecessor basic block of the
3528current block. Only values of <a href="#t_firstclass">first class</a>
3529type may be used as the value arguments to the PHI node. Only labels
3530may be used as the label arguments.</p>
3531<p>There must be no non-phi instructions between the start of a basic
3532block and the PHI instructions: i.e. PHI instructions must be first in
3533a basic block.</p>
3534<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3535<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3536specified by the pair corresponding to the predecessor basic block that executed
3537just prior to the current block.</p>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3538<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3539<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]3540</div>
3541
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3542<!-- _______________________________________________________________________ -->
3543<div class="doc_subsubsection">
3544 <a name="i_select">'<tt>select</tt>' Instruction</a>
3545</div>
3546
3547<div class="doc_text">
3548
3549<h5>Syntax:</h5>
3550
3551<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3552 &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]3553</pre>
3554
3555<h5>Overview:</h5>
3556
3557<p>
3558The '<tt>select</tt>' instruction is used to choose one value based on a
3559condition, without branching.
3560</p>
3561
3562
3563<h5>Arguments:</h5>
3564
3565<p>
3566The '<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.
3567</p>
3568
3569<h5>Semantics:</h5>
3570
3571<p>
3572If the boolean condition evaluates to true, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3573value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3574</p>
3575
3576<h5>Example:</h5>
3577
3578<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3579 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3580</pre>
3581</div>
3582
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]3583
3584<!-- _______________________________________________________________________ -->
3585<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3586 <a name="i_call">'<tt>call</tt>' Instruction</a>
3587</div>
3588
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3589<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3590
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3591<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3592<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3593 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3594</pre>
3595
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3596<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3597
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3598<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3599
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3600<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3601
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3602<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3603
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3604<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3605 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3606 <p>The optional "tail" marker indicates whether the callee function accesses
3607 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3608 function call is eligible for tail call optimization. Note that calls may
3609 be marked "tail" even if they do not occur before a <a
3610 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3611 </li>
3612 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3613 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3614 convention</a> the call should use. If none is specified, the call defaults
3615 to using C calling conventions.
3616 </li>
3617 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3618 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3619 the type of the return value. Functions that return no value are marked
3620 <tt><a href="#t_void">void</a></tt>.</p>
3621 </li>
3622 <li>
3623 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3624 value being invoked. The argument types must match the types implied by
3625 this signature. This type can be omitted if the function is not varargs
3626 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3627 </li>
3628 <li>
3629 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3630 be invoked. In most cases, this is a direct function invocation, but
3631 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3632 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3633 </li>
3634 <li>
3635 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]3636 function signature argument types. All arguments must be of
3637 <a href="#t_firstclass">first class</a> type. If the function signature
3638 indicates the function accepts a variable number of arguments, the extra
3639 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3640 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3641</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3642
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3643<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3644
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3645<p>The '<tt>call</tt>' instruction is used to cause control flow to
3646transfer to a specified function, with its incoming arguments bound to
3647the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3648instruction in the called function, control flow continues with the
3649instruction after the function call, and the return value of the
3650function is bound to the result argument. This is a simpler case of
3651the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3652
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3653<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3654
3655<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3656 %retval = call i32 @test(i32 %argc)
3657 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3658 %X = tail call i32 @foo()
3659 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3660 %Z = call void %foo(i8 97 signext)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3661</pre>
3662
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3663</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3664
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3665<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3666<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3667 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3668</div>
3669
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3670<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3671
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3672<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3673
3674<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3675 &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]3676</pre>
3677
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3678<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3679
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3680<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3681the "variable argument" area of a function call. It is used to implement the
3682<tt>va_arg</tt> macro in C.</p>
3683
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3684<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3685
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3686<p>This instruction takes a <tt>va_list*</tt> value and the type of
3687the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3688increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3689actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3690
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3691<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3692
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3693<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3694type from the specified <tt>va_list</tt> and causes the
3695<tt>va_list</tt> to point to the next argument. For more information,
3696see the variable argument handling <a href="#int_varargs">Intrinsic
3697Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3698
3699<p>It is legal for this instruction to be called in a function which does not
3700take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3701function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3702
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3703<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3704href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3705argument.</p>
3706
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3707<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3708
3709<p>See the <a href="#int_varargs">variable argument processing</a> section.</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 Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3714<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3715<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3716
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3717<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3718
3719<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3720well known names and semantics and are required to follow certain restrictions.
3721Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3722language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]3723adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3724
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3725<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3726prefix is reserved in LLVM for intrinsic names; thus, function names may not
3727begin with this prefix. Intrinsic functions must always be external functions:
3728you cannot define the body of intrinsic functions. Intrinsic functions may
3729only be used in call or invoke instructions: it is illegal to take the address
3730of an intrinsic function. Additionally, because intrinsic functions are part
3731of the LLVM language, it is required if any are added that they be documented
3732here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3733
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]3734<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3735a family of functions that perform the same operation but on different data
3736types. Because LLVM can represent over 8 million different integer types,
3737overloading is used commonly to allow an intrinsic function to operate on any
3738integer type. One or more of the argument types or the result type can be
3739overloaded to accept any integer type. Argument types may also be defined as
3740exactly matching a previous argument's type or the result type. This allows an
3741intrinsic function which accepts multiple arguments, but needs all of them to
3742be of the same type, to only be overloaded with respect to a single argument or
3743the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3744
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]3745<p>Overloaded intrinsics will have the names of its overloaded argument types
3746encoded into its function name, each preceded by a period. Only those types
3747which are overloaded result in a name suffix. Arguments whose type is matched
3748against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3749take an integer of any width and returns an integer of exactly the same integer
3750width. This leads to a family of functions such as
3751<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3752Only one type, the return type, is overloaded, and only one type suffix is
3753required. Because the argument's type is matched against the return type, it
3754does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3755
3756<p>To learn how to add an intrinsic function, please see the
3757<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3758</p>
3759
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3760</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3761
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3762<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3763<div class="doc_subsection">
3764 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3765</div>
3766
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3767<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3768
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3769<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3770 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3771intrinsic functions. These functions are related to the similarly
3772named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3773
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3774<p>All of these functions operate on arguments that use a
3775target-specific value type "<tt>va_list</tt>". The LLVM assembly
3776language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3777transformations should be prepared to handle these functions regardless of
3778the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3779
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]3780<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]3781instruction and the variable argument handling intrinsic functions are
3782used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3783
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3784<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3785<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3786define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3787 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3788 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3789 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3790 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3791
3792 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3793 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3794
3795 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3796 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3797 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3798 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3799 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3800
3801 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3802 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3803 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3804}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3805
3806declare void @llvm.va_start(i8*)
3807declare void @llvm.va_copy(i8*, i8*)
3808declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3809</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3810</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3811
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3812</div>
3813
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3814<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3815<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3816 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3817</div>
3818
3819
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3820<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3821<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3822<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3823<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3824<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3825<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3826href="#i_va_arg">va_arg</a></tt>.</p>
3827
3828<h5>Arguments:</h5>
3829
3830<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3831
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3832<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3833
3834<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3835macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3836<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]3837<tt>va_arg</tt> will produce the first variable argument passed to the function.
3838Unlike 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]3839last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3840
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3841</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3842
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3843<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3844<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3845 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3846</div>
3847
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3848<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3849<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3850<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3851<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3852
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3853<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3854which 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]3855or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3856
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3857<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3858
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3859<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]3860
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3861<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3862
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3863<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]3864macro available in C. In a target-dependent way, it destroys the
3865<tt>va_list</tt> element to which the argument points. Calls to <a
3866href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3867<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3868<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3869
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3870</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3871
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3872<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3873<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3874 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3875</div>
3876
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3877<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3878
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3879<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3880
3881<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3882 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3883</pre>
3884
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3885<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3886
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3887<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3888from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3889
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3890<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3891
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3892<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]3893The 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]3894
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3895
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3896<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3897
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3898<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3899macro available in C. In a target-dependent way, it copies the source
3900<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3901intrinsic is necessary because the <tt><a href="#int_va_start">
3902llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3903example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3904
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3905</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3906
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3907<!-- ======================================================================= -->
3908<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3909 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3910</div>
3911
3912<div class="doc_text">
3913
3914<p>
3915LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3916Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3917These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3918stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3919href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3920Front-ends for type-safe garbage collected languages should generate these
3921intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3922href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3923</p>
3924</div>
3925
3926<!-- _______________________________________________________________________ -->
3927<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3928 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3929</div>
3930
3931<div class="doc_text">
3932
3933<h5>Syntax:</h5>
3934
3935<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]3936 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3937</pre>
3938
3939<h5>Overview:</h5>
3940
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3941<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]3942the code generator, and allows some metadata to be associated with it.</p>
3943
3944<h5>Arguments:</h5>
3945
3946<p>The first argument specifies the address of a stack object that contains the
3947root pointer. The second pointer (which must be either a constant or a global
3948value address) contains the meta-data to be associated with the root.</p>
3949
3950<h5>Semantics:</h5>
3951
3952<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3953location. At compile-time, the code generator generates information to allow
3954the runtime to find the pointer at GC safe points.
3955</p>
3956
3957</div>
3958
3959
3960<!-- _______________________________________________________________________ -->
3961<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3962 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3963</div>
3964
3965<div class="doc_text">
3966
3967<h5>Syntax:</h5>
3968
3969<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]3970 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3971</pre>
3972
3973<h5>Overview:</h5>
3974
3975<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
3976locations, allowing garbage collector implementations that require read
3977barriers.</p>
3978
3979<h5>Arguments:</h5>
3980
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]3981<p>The second argument is the address to read from, which should be an address
3982allocated from the garbage collector. The first object is a pointer to the
3983start of the referenced object, if needed by the language runtime (otherwise
3984null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3985
3986<h5>Semantics:</h5>
3987
3988<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
3989instruction, but may be replaced with substantially more complex code by the
3990garbage collector runtime, as needed.</p>
3991
3992</div>
3993
3994
3995<!-- _______________________________________________________________________ -->
3996<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3997 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3998</div>
3999
4000<div class="doc_text">
4001
4002<h5>Syntax:</h5>
4003
4004<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4005 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4006</pre>
4007
4008<h5>Overview:</h5>
4009
4010<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4011locations, allowing garbage collector implementations that require write
4012barriers (such as generational or reference counting collectors).</p>
4013
4014<h5>Arguments:</h5>
4015
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4016<p>The first argument is the reference to store, the second is the start of the
4017object to store it to, and the third is the address of the field of Obj to
4018store to. If the runtime does not require a pointer to the object, Obj may be
4019null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4020
4021<h5>Semantics:</h5>
4022
4023<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4024instruction, but may be replaced with substantially more complex code by the
4025garbage collector runtime, as needed.</p>
4026
4027</div>
4028
4029
4030
4031<!-- ======================================================================= -->
4032<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4033 <a name="int_codegen">Code Generator Intrinsics</a>
4034</div>
4035
4036<div class="doc_text">
4037<p>
4038These intrinsics are provided by LLVM to expose special features that may only
4039be implemented with code generator support.
4040</p>
4041
4042</div>
4043
4044<!-- _______________________________________________________________________ -->
4045<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4046 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4047</div>
4048
4049<div class="doc_text">
4050
4051<h5>Syntax:</h5>
4052<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4053 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4054</pre>
4055
4056<h5>Overview:</h5>
4057
4058<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4059The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4060target-specific value indicating the return address of the current function
4061or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4062</p>
4063
4064<h5>Arguments:</h5>
4065
4066<p>
4067The argument to this intrinsic indicates which function to return the address
4068for. Zero indicates the calling function, one indicates its caller, etc. The
4069argument is <b>required</b> to be a constant integer value.
4070</p>
4071
4072<h5>Semantics:</h5>
4073
4074<p>
4075The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4076the return address of the specified call frame, or zero if it cannot be
4077identified. The value returned by this intrinsic is likely to be incorrect or 0
4078for arguments other than zero, so it should only be used for debugging purposes.
4079</p>
4080
4081<p>
4082Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4083aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4084source-language caller.
4085</p>
4086</div>
4087
4088
4089<!-- _______________________________________________________________________ -->
4090<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4091 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4092</div>
4093
4094<div class="doc_text">
4095
4096<h5>Syntax:</h5>
4097<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4098 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4099</pre>
4100
4101<h5>Overview:</h5>
4102
4103<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4104The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4105target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4106</p>
4107
4108<h5>Arguments:</h5>
4109
4110<p>
4111The argument to this intrinsic indicates which function to return the frame
4112pointer for. Zero indicates the calling function, one indicates its caller,
4113etc. The argument is <b>required</b> to be a constant integer value.
4114</p>
4115
4116<h5>Semantics:</h5>
4117
4118<p>
4119The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4120the frame address of the specified call frame, or zero if it cannot be
4121identified. The value returned by this intrinsic is likely to be incorrect or 0
4122for arguments other than zero, so it should only be used for debugging purposes.
4123</p>
4124
4125<p>
4126Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4127aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4128source-language caller.
4129</p>
4130</div>
4131
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4132<!-- _______________________________________________________________________ -->
4133<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4134 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4135</div>
4136
4137<div class="doc_text">
4138
4139<h5>Syntax:</h5>
4140<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4141 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4142</pre>
4143
4144<h5>Overview:</h5>
4145
4146<p>
4147The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4148the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4149<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4150features like scoped automatic variable sized arrays in C99.
4151</p>
4152
4153<h5>Semantics:</h5>
4154
4155<p>
4156This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4157href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4158<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4159<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4160state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4161practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4162that were allocated after the <tt>llvm.stacksave</tt> was executed.
4163</p>
4164
4165</div>
4166
4167<!-- _______________________________________________________________________ -->
4168<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4169 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4170</div>
4171
4172<div class="doc_text">
4173
4174<h5>Syntax:</h5>
4175<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4176 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4177</pre>
4178
4179<h5>Overview:</h5>
4180
4181<p>
4182The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4183the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4184href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4185useful for implementing language features like scoped automatic variable sized
4186arrays in C99.
4187</p>
4188
4189<h5>Semantics:</h5>
4190
4191<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4192See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4193</p>
4194
4195</div>
4196
4197
4198<!-- _______________________________________________________________________ -->
4199<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4200 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4201</div>
4202
4203<div class="doc_text">
4204
4205<h5>Syntax:</h5>
4206<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4207 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4208</pre>
4209
4210<h5>Overview:</h5>
4211
4212
4213<p>
4214The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4215a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4216no
4217effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4218characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4219</p>
4220
4221<h5>Arguments:</h5>
4222
4223<p>
4224<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4225determining if the fetch should be for a read (0) or write (1), and
4226<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4227locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4228<tt>locality</tt> arguments must be constant integers.
4229</p>
4230
4231<h5>Semantics:</h5>
4232
4233<p>
4234This intrinsic does not modify the behavior of the program. In particular,
4235prefetches cannot trap and do not produce a value. On targets that support this
4236intrinsic, the prefetch can provide hints to the processor cache for better
4237performance.
4238</p>
4239
4240</div>
4241
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4242<!-- _______________________________________________________________________ -->
4243<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4244 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4245</div>
4246
4247<div class="doc_text">
4248
4249<h5>Syntax:</h5>
4250<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4251 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4252</pre>
4253
4254<h5>Overview:</h5>
4255
4256
4257<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4258The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4259(PC) in a region of
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4260code to simulators and other tools. The method is target specific, but it is
4261expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohendc6bfea2005-11-11 02:15:27 +0000[diff] [blame]4262The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnere64d41d2005-11-15 06:07:55 +0000[diff] [blame]4263after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4264optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4265correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4266</p>
4267
4268<h5>Arguments:</h5>
4269
4270<p>
4271<tt>id</tt> is a numerical id identifying the marker.
4272</p>
4273
4274<h5>Semantics:</h5>
4275
4276<p>
4277This intrinsic does not modify the behavior of the program. Backends that do not
4278support this intrinisic may ignore it.
4279</p>
4280
4281</div>
4282
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4283<!-- _______________________________________________________________________ -->
4284<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4285 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +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 i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4293</pre>
4294
4295<h5>Overview:</h5>
4296
4297
4298<p>
4299The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4300counter register (or similar low latency, high accuracy clocks) on those targets
4301that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4302As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4303should only be used for small timings.
4304</p>
4305
4306<h5>Semantics:</h5>
4307
4308<p>
4309When directly supported, reading the cycle counter should not modify any memory.
4310Implementations are allowed to either return a application specific value or a
4311system wide value. On backends without support, this is lowered to a constant 0.
4312</p>
4313
4314</div>
4315
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4316<!-- ======================================================================= -->
4317<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4318 <a name="int_libc">Standard C Library Intrinsics</a>
4319</div>
4320
4321<div class="doc_text">
4322<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4323LLVM provides intrinsics for a few important standard C library functions.
4324These intrinsics allow source-language front-ends to pass information about the
4325alignment of the pointer arguments to the code generator, providing opportunity
4326for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4327</p>
4328
4329</div>
4330
4331<!-- _______________________________________________________________________ -->
4332<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4333 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4334</div>
4335
4336<div class="doc_text">
4337
4338<h5>Syntax:</h5>
4339<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4340 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4341 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4342 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4343 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4344</pre>
4345
4346<h5>Overview:</h5>
4347
4348<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4349The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4350location to the destination location.
4351</p>
4352
4353<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4354Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4355intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4356</p>
4357
4358<h5>Arguments:</h5>
4359
4360<p>
4361The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4362the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4363specifying the number of bytes to copy, and the fourth argument is the alignment
4364of the source and destination locations.
4365</p>
4366
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4367<p>
4368If 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]4369the caller guarantees that both the source and destination pointers are aligned
4370to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4371</p>
4372
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4373<h5>Semantics:</h5>
4374
4375<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4376The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4377location to the destination location, which are not allowed to overlap. It
4378copies "len" bytes of memory over. If the argument is known to be aligned to
4379some boundary, this can be specified as the fourth argument, otherwise it should
4380be set to 0 or 1.
4381</p>
4382</div>
4383
4384
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4385<!-- _______________________________________________________________________ -->
4386<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4387 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4388</div>
4389
4390<div class="doc_text">
4391
4392<h5>Syntax:</h5>
4393<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4394 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4395 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4396 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4397 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4398</pre>
4399
4400<h5>Overview:</h5>
4401
4402<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4403The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4404location to the destination location. It is similar to the
4405'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4406</p>
4407
4408<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4409Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4410intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4411</p>
4412
4413<h5>Arguments:</h5>
4414
4415<p>
4416The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4417the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4418specifying the number of bytes to copy, and the fourth argument is the alignment
4419of the source and destination locations.
4420</p>
4421
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4422<p>
4423If 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]4424the caller guarantees that the source and destination pointers are aligned to
4425that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4426</p>
4427
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4428<h5>Semantics:</h5>
4429
4430<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4431The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4432location to the destination location, which may overlap. It
4433copies "len" bytes of memory over. If the argument is known to be aligned to
4434some boundary, this can be specified as the fourth argument, otherwise it should
4435be set to 0 or 1.
4436</p>
4437</div>
4438
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4439
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4440<!-- _______________________________________________________________________ -->
4441<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4442 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4443</div>
4444
4445<div class="doc_text">
4446
4447<h5>Syntax:</h5>
4448<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4449 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4450 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4451 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4452 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4453</pre>
4454
4455<h5>Overview:</h5>
4456
4457<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4458The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4459byte value.
4460</p>
4461
4462<p>
4463Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4464does not return a value, and takes an extra alignment argument.
4465</p>
4466
4467<h5>Arguments:</h5>
4468
4469<p>
4470The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4471byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4472argument specifying the number of bytes to fill, and the fourth argument is the
4473known alignment of destination location.
4474</p>
4475
4476<p>
4477If 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]4478the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4479</p>
4480
4481<h5>Semantics:</h5>
4482
4483<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4484The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4485the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4486destination location. If the argument is known to be aligned to some boundary,
4487this can be specified as the fourth argument, otherwise it should be set to 0 or
44881.
4489</p>
4490</div>
4491
4492
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4493<!-- _______________________________________________________________________ -->
4494<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4495 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4496</div>
4497
4498<div class="doc_text">
4499
4500<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4501<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4502floating point or vector of floating point type. Not all targets support all
4503types however.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4504<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4505 declare float @llvm.sqrt.f32(float %Val)
4506 declare double @llvm.sqrt.f64(double %Val)
4507 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4508 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4509 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4510</pre>
4511
4512<h5>Overview:</h5>
4513
4514<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4515The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4516returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4517<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4518negative numbers (which allows for better optimization).
4519</p>
4520
4521<h5>Arguments:</h5>
4522
4523<p>
4524The argument and return value are floating point numbers of the same type.
4525</p>
4526
4527<h5>Semantics:</h5>
4528
4529<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]4530This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4531floating point number.
4532</p>
4533</div>
4534
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4535<!-- _______________________________________________________________________ -->
4536<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4537 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4538</div>
4539
4540<div class="doc_text">
4541
4542<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4543<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4544floating point or vector of floating point type. Not all targets support all
4545types however.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4546<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4547 declare float @llvm.powi.f32(float %Val, i32 %power)
4548 declare double @llvm.powi.f64(double %Val, i32 %power)
4549 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4550 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4551 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4552</pre>
4553
4554<h5>Overview:</h5>
4555
4556<p>
4557The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4558specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4559multiplications is not defined. When a vector of floating point type is
4560used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4561</p>
4562
4563<h5>Arguments:</h5>
4564
4565<p>
4566The second argument is an integer power, and the first is a value to raise to
4567that power.
4568</p>
4569
4570<h5>Semantics:</h5>
4571
4572<p>
4573This function returns the first value raised to the second power with an
4574unspecified sequence of rounding operations.</p>
4575</div>
4576
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4577<!-- _______________________________________________________________________ -->
4578<div class="doc_subsubsection">
4579 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4580</div>
4581
4582<div class="doc_text">
4583
4584<h5>Syntax:</h5>
4585<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4586floating point or vector of floating point type. Not all targets support all
4587types however.
4588<pre>
4589 declare float @llvm.sin.f32(float %Val)
4590 declare double @llvm.sin.f64(double %Val)
4591 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4592 declare fp128 @llvm.sin.f128(fp128 %Val)
4593 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4594</pre>
4595
4596<h5>Overview:</h5>
4597
4598<p>
4599The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4600</p>
4601
4602<h5>Arguments:</h5>
4603
4604<p>
4605The argument and return value are floating point numbers of the same type.
4606</p>
4607
4608<h5>Semantics:</h5>
4609
4610<p>
4611This function returns the sine of the specified operand, returning the
4612same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4613conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4614</div>
4615
4616<!-- _______________________________________________________________________ -->
4617<div class="doc_subsubsection">
4618 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4619</div>
4620
4621<div class="doc_text">
4622
4623<h5>Syntax:</h5>
4624<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4625floating point or vector of floating point type. Not all targets support all
4626types however.
4627<pre>
4628 declare float @llvm.cos.f32(float %Val)
4629 declare double @llvm.cos.f64(double %Val)
4630 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4631 declare fp128 @llvm.cos.f128(fp128 %Val)
4632 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4633</pre>
4634
4635<h5>Overview:</h5>
4636
4637<p>
4638The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4639</p>
4640
4641<h5>Arguments:</h5>
4642
4643<p>
4644The argument and return value are floating point numbers of the same type.
4645</p>
4646
4647<h5>Semantics:</h5>
4648
4649<p>
4650This function returns the cosine of the specified operand, returning the
4651same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4652conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4653</div>
4654
4655<!-- _______________________________________________________________________ -->
4656<div class="doc_subsubsection">
4657 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4658</div>
4659
4660<div class="doc_text">
4661
4662<h5>Syntax:</h5>
4663<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4664floating point or vector of floating point type. Not all targets support all
4665types however.
4666<pre>
4667 declare float @llvm.pow.f32(float %Val, float %Power)
4668 declare double @llvm.pow.f64(double %Val, double %Power)
4669 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4670 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4671 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4672</pre>
4673
4674<h5>Overview:</h5>
4675
4676<p>
4677The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4678specified (positive or negative) power.
4679</p>
4680
4681<h5>Arguments:</h5>
4682
4683<p>
4684The second argument is a floating point power, and the first is a value to
4685raise to that power.
4686</p>
4687
4688<h5>Semantics:</h5>
4689
4690<p>
4691This function returns the first value raised to the second power,
4692returning the
4693same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4694conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4695</div>
4696
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4697
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4698<!-- ======================================================================= -->
4699<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4700 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4701</div>
4702
4703<div class="doc_text">
4704<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4705LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4706These allow efficient code generation for some algorithms.
4707</p>
4708
4709</div>
4710
4711<!-- _______________________________________________________________________ -->
4712<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4713 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4714</div>
4715
4716<div class="doc_text">
4717
4718<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4719<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4720type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4721<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4722 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4723 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4724 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4725</pre>
4726
4727<h5>Overview:</h5>
4728
4729<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]4730The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4731values with an even number of bytes (positive multiple of 16 bits). These are
4732useful for performing operations on data that is not in the target's native
4733byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4734</p>
4735
4736<h5>Semantics:</h5>
4737
4738<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4739The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4740and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4741intrinsic returns an i32 value that has the four bytes of the input i32
4742swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4743i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4744<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4745additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4746</p>
4747
4748</div>
4749
4750<!-- _______________________________________________________________________ -->
4751<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4752 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4753</div>
4754
4755<div class="doc_text">
4756
4757<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4758<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4759width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4760<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4761 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4762 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4763 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4764 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4765 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4766</pre>
4767
4768<h5>Overview:</h5>
4769
4770<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]4771The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4772value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4773</p>
4774
4775<h5>Arguments:</h5>
4776
4777<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4778The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4779integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4780</p>
4781
4782<h5>Semantics:</h5>
4783
4784<p>
4785The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4786</p>
4787</div>
4788
4789<!-- _______________________________________________________________________ -->
4790<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4791 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4792</div>
4793
4794<div class="doc_text">
4795
4796<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4797<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4798integer bit width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4799<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4800 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4801 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4802 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4803 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4804 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4805</pre>
4806
4807<h5>Overview:</h5>
4808
4809<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4810The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4811leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4812</p>
4813
4814<h5>Arguments:</h5>
4815
4816<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4817The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4818integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4819</p>
4820
4821<h5>Semantics:</h5>
4822
4823<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4824The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4825in 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]4826of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4827</p>
4828</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4829
4830
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4831
4832<!-- _______________________________________________________________________ -->
4833<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4834 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4835</div>
4836
4837<div class="doc_text">
4838
4839<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4840<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4841integer bit width. Not all targets support all bit widths however.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4842<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4843 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4844 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4845 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4846 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4847 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4848</pre>
4849
4850<h5>Overview:</h5>
4851
4852<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4853The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4854trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4855</p>
4856
4857<h5>Arguments:</h5>
4858
4859<p>
4860The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4861integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4862</p>
4863
4864<h5>Semantics:</h5>
4865
4866<p>
4867The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4868in a variable. If the src == 0 then the result is the size in bits of the type
4869of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4870</p>
4871</div>
4872
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]4873<!-- _______________________________________________________________________ -->
4874<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4875 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4876</div>
4877
4878<div class="doc_text">
4879
4880<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4881<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4882on any integer bit width.
4883<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4884 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4885 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4886</pre>
4887
4888<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4889<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4890range of bits from an integer value and returns them in the same bit width as
4891the original value.</p>
4892
4893<h5>Arguments:</h5>
4894<p>The first argument, <tt>%val</tt> and the result may be integer types of
4895any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4896arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4897
4898<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4899<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4900of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4901<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4902operates in forward mode.</p>
4903<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4904right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4905only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4906<ol>
4907 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4908 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4909 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4910 to determine the number of bits to retain.</li>
4911 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4912 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4913</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]4914<p>In reverse mode, a similar computation is made except that the bits are
4915returned in the reverse order. So, for example, if <tt>X</tt> has the value
4916<tt>i16 0x0ACF (101011001111)</tt> and we apply
4917<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4918<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4919</div>
4920
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4921<div class="doc_subsubsection">
4922 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4923</div>
4924
4925<div class="doc_text">
4926
4927<h5>Syntax:</h5>
4928<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4929on any integer bit width.
4930<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4931 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4932 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4933</pre>
4934
4935<h5>Overview:</h5>
4936<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4937of bits in an integer value with another integer value. It returns the integer
4938with the replaced bits.</p>
4939
4940<h5>Arguments:</h5>
4941<p>The first argument, <tt>%val</tt> and the result may be integer types of
4942any bit width but they must have the same bit width. <tt>%val</tt> is the value
4943whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4944integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4945type since they specify only a bit index.</p>
4946
4947<h5>Semantics:</h5>
4948<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4949of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4950<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4951operates in forward mode.</p>
4952<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4953truncating it down to the size of the replacement area or zero extending it
4954up to that size.</p>
4955<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
4956are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
4957in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
4958to the <tt>%hi</tt>th bit.
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]4959<p>In reverse mode, a similar computation is made except that the bits are
4960reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
4961<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]4962<h5>Examples:</h5>
4963<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]4964 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]4965 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
4966 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
4967 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]4968 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]4969</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4970</div>
4971
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4972<!-- ======================================================================= -->
4973<div class="doc_subsection">
4974 <a name="int_debugger">Debugger Intrinsics</a>
4975</div>
4976
4977<div class="doc_text">
4978<p>
4979The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
4980are described in the <a
4981href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
4982Debugging</a> document.
4983</p>
4984</div>
4985
4986
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]4987<!-- ======================================================================= -->
4988<div class="doc_subsection">
4989 <a name="int_eh">Exception Handling Intrinsics</a>
4990</div>
4991
4992<div class="doc_text">
4993<p> The LLVM exception handling intrinsics (which all start with
4994<tt>llvm.eh.</tt> prefix), are described in the <a
4995href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
4996Handling</a> document. </p>
4997</div>
4998
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]4999<!-- ======================================================================= -->
5000<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5001 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5002</div>
5003
5004<div class="doc_text">
5005<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5006 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5007 the <tt>nest</tt> attribute, from a function. The result is a callable
5008 function pointer lacking the nest parameter - the caller does not need
5009 to provide a value for it. Instead, the value to use is stored in
5010 advance in a "trampoline", a block of memory usually allocated
5011 on the stack, which also contains code to splice the nest value into the
5012 argument list. This is used to implement the GCC nested function address
5013 extension.
5014</p>
5015<p>
5016 For example, if the function is
5017 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5018 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5019<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5020 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5021 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5022 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5023 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5024</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5025 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5026 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5027</div>
5028
5029<!-- _______________________________________________________________________ -->
5030<div class="doc_subsubsection">
5031 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5032</div>
5033<div class="doc_text">
5034<h5>Syntax:</h5>
5035<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5036declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5037</pre>
5038<h5>Overview:</h5>
5039<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5040 This fills the memory pointed to by <tt>tramp</tt> with code
5041 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5042</p>
5043<h5>Arguments:</h5>
5044<p>
5045 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5046 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5047 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5048 intrinsic. Note that the size and the alignment are target-specific - LLVM
5049 currently provides no portable way of determining them, so a front-end that
5050 generates this intrinsic needs to have some target-specific knowledge.
5051 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5052</p>
5053<h5>Semantics:</h5>
5054<p>
5055 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5056 dependent code, turning it into a function. A pointer to this function is
5057 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5058 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5059 before being called. The new function's signature is the same as that of
5060 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5061 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5062 of pointer type. Calling the new function is equivalent to calling
5063 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5064 missing <tt>nest</tt> argument. If, after calling
5065 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5066 modified, then the effect of any later call to the returned function pointer is
5067 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5068</p>
5069</div>
5070
5071<!-- ======================================================================= -->
5072<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5073 <a name="int_general">General Intrinsics</a>
5074</div>
5075
5076<div class="doc_text">
5077<p> This class of intrinsics is designed to be generic and has
5078no specific purpose. </p>
5079</div>
5080
5081<!-- _______________________________________________________________________ -->
5082<div class="doc_subsubsection">
5083 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5084</div>
5085
5086<div class="doc_text">
5087
5088<h5>Syntax:</h5>
5089<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]5090 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5091</pre>
5092
5093<h5>Overview:</h5>
5094
5095<p>
5096The '<tt>llvm.var.annotation</tt>' intrinsic
5097</p>
5098
5099<h5>Arguments:</h5>
5100
5101<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]5102The first argument is a pointer to a value, the second is a pointer to a
5103global string, the third is a pointer to a global string which is the source
5104file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5105</p>
5106
5107<h5>Semantics:</h5>
5108
5109<p>
5110This intrinsic allows annotation of local variables with arbitrary strings.
5111This can be useful for special purpose optimizations that want to look for these
5112 annotations. These have no other defined use, they are ignored by code
5113 generation and optimization.
5114</div>
5115
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5116<!-- _______________________________________________________________________ -->
5117<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]5118 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5119</div>
5120
5121<div class="doc_text">
5122
5123<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5124<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5125any integer bit width.
5126</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5127<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]5128 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5129 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5130 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5131 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5132 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5133</pre>
5134
5135<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5136
5137<p>
5138The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5139</p>
5140
5141<h5>Arguments:</h5>
5142
5143<p>
5144The first argument is an integer value (result of some expression),
5145the second is a pointer to a global string, the third is a pointer to a global
5146string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5147It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5148</p>
5149
5150<h5>Semantics:</h5>
5151
5152<p>
5153This intrinsic allows annotations to be put on arbitrary expressions
5154with arbitrary strings. This can be useful for special purpose optimizations
5155that want to look for these annotations. These have no other defined use, they
5156are ignored by code generation and optimization.
5157</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5158
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5159<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5160<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]5161<address>
5162 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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5166
5167 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]5168 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]5169 Last modified: $Date$
5170</address>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5171</body>
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