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Chris Lattner757528b0b2004-05-23 21:06:01 +000012
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Chris Lattner757528b0b2004-05-23 21:06:01 +000014
Chris Lattner48b383b02003-11-25 01:02:51 +000015<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +000016<ol>
Misha Brukman76307852003-11-08 01:05:38 +000017 <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 +000020 <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 +000023 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +000024 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +000025 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +000026 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov546ea7e2007-04-29 18:02:48 +000027 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +000028 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +000029 <li><a href="#gc">Garbage Collector Names</a></li>
Devang Patel8af98cd2008-09-04 23:10:26 +000030 <li><a href="#notes">Function Notes</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +000031 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +000032 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +000033 </ol>
34 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +000035 <li><a href="#typesystem">Type System</a>
36 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +000037 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +000038 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +000039 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +000040 <li><a href="#t_floating">Floating Point Types</a></li>
41 <li><a href="#t_void">Void Type</a></li>
42 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000043 </ol>
44 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +000045 <li><a href="#t_derived">Derived Types</a>
46 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +000047 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000048 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +000049 <li><a href="#t_function">Function Type</a></li>
50 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000051 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +000052 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +000053 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +000054 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000055 </ol>
56 </li>
57 </ol>
58 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +000059 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +000060 <ol>
61 <li><a href="#simpleconstants">Simple Constants</a>
62 <li><a href="#aggregateconstants">Aggregate Constants</a>
63 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
64 <li><a href="#undefvalues">Undefined Values</a>
65 <li><a href="#constantexprs">Constant Expressions</a>
66 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +000067 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +000068 <li><a href="#othervalues">Other Values</a>
69 <ol>
70 <li><a href="#inlineasm">Inline Assembler Expressions</a>
71 </ol>
72 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +000073 <li><a href="#instref">Instruction Reference</a>
74 <ol>
75 <li><a href="#terminators">Terminator Instructions</a>
76 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +000077 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
78 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +000079 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
80 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000081 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +000082 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000083 </ol>
84 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +000085 <li><a href="#binaryops">Binary Operations</a>
86 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +000087 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
88 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
89 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +000090 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
91 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
92 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +000093 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
94 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
95 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +000096 </ol>
97 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +000098 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
99 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000100 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
101 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
102 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000103 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000104 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000105 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000106 </ol>
107 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000108 <li><a href="#vectorops">Vector Operations</a>
109 <ol>
110 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
111 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
112 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000113 </ol>
114 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000115 <li><a href="#aggregateops">Aggregate Operations</a>
116 <ol>
117 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
118 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
119 </ol>
120 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000121 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000122 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000123 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
124 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
125 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000126 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
127 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
128 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000129 </ol>
130 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000131 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000132 <ol>
133 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
134 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000138 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
140 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
141 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000142 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
143 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000144 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000145 </ol>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000146 <li><a href="#otherops">Other Operations</a>
147 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000148 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
149 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000150 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
151 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000152 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000153 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000154 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000155 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Pateld6cff512008-03-10 20:49:15 +0000156 <li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000157 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000158 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000159 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000160 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000161 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000162 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000163 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
164 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000165 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000168 </ol>
169 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000170 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
171 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000172 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000175 </ol>
176 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000177 <li><a href="#int_codegen">Code Generator Intrinsics</a>
178 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000179 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
182 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
183 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
184 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
185 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000186 </ol>
187 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000188 <li><a href="#int_libc">Standard C Library Intrinsics</a>
189 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000190 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000195 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000198 </ol>
199 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000200 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000201 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000202 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000203 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000206 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000208 </ol>
209 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000210 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000211 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000212 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000213 <ol>
214 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000215 </ol>
216 </li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000217 <li><a href="#int_atomics">Atomic intrinsics</a>
218 <ol>
Andrew Lenharth95528942008-02-21 06:45:13 +0000219 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang6a490372008-06-25 08:15:39 +0000220 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth95528942008-02-21 06:45:13 +0000221 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang6a490372008-06-25 08:15:39 +0000222 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
223 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
224 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
225 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
226 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
227 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
228 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
229 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
230 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
231 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000232 </ol>
233 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000234 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000235 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000236 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000237 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000238 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000239 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000240 <li><a href="#int_trap">
241 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000242 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000243 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000244 </ol>
245 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000246</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000247
248<div class="doc_author">
249 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
250 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000251</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000252
Chris Lattner2f7c9632001-06-06 20:29:01 +0000253<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000254<div class="doc_section"> <a name="abstract">Abstract </a></div>
255<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000256
Misha Brukman76307852003-11-08 01:05:38 +0000257<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000258<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000259LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000260type safety, low-level operations, flexibility, and the capability of
261representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000262representation used throughout all phases of the LLVM compilation
263strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000264</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000265
Chris Lattner2f7c9632001-06-06 20:29:01 +0000266<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000267<div class="doc_section"> <a name="introduction">Introduction</a> </div>
268<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000269
Misha Brukman76307852003-11-08 01:05:38 +0000270<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000271
Chris Lattner48b383b02003-11-25 01:02:51 +0000272<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000273different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000274representation (suitable for fast loading by a Just-In-Time compiler),
275and as a human readable assembly language representation. This allows
276LLVM to provide a powerful intermediate representation for efficient
277compiler transformations and analysis, while providing a natural means
278to debug and visualize the transformations. The three different forms
279of LLVM are all equivalent. This document describes the human readable
280representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000281
John Criswell4a3327e2005-05-13 22:25:59 +0000282<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000283while being expressive, typed, and extensible at the same time. It
284aims to be a "universal IR" of sorts, by being at a low enough level
285that high-level ideas may be cleanly mapped to it (similar to how
286microprocessors are "universal IR's", allowing many source languages to
287be mapped to them). By providing type information, LLVM can be used as
288the target of optimizations: for example, through pointer analysis, it
289can be proven that a C automatic variable is never accessed outside of
290the current function... allowing it to be promoted to a simple SSA
291value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000292
Misha Brukman76307852003-11-08 01:05:38 +0000293</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000294
Chris Lattner2f7c9632001-06-06 20:29:01 +0000295<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000296<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000297
Misha Brukman76307852003-11-08 01:05:38 +0000298<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000299
Chris Lattner48b383b02003-11-25 01:02:51 +0000300<p>It is important to note that this document describes 'well formed'
301LLVM assembly language. There is a difference between what the parser
302accepts and what is considered 'well formed'. For example, the
303following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000304
Bill Wendling3716c5d2007-05-29 09:04:49 +0000305<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000306<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000307%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000308</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000309</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000310
Chris Lattner48b383b02003-11-25 01:02:51 +0000311<p>...because the definition of <tt>%x</tt> does not dominate all of
312its uses. The LLVM infrastructure provides a verification pass that may
313be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000314automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000315the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000316by the verifier pass indicate bugs in transformation passes or input to
317the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000318</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000319
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000320<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000322<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000323<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000324<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000325
Misha Brukman76307852003-11-08 01:05:38 +0000326<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000327
Reid Spencerb23b65f2007-08-07 14:34:28 +0000328 <p>LLVM identifiers come in two basic types: global and local. Global
329 identifiers (functions, global variables) begin with the @ character. Local
330 identifiers (register names, types) begin with the % character. Additionally,
331 there are three different formats for identifiers, for different purposes:
Chris Lattner757528b0b2004-05-23 21:06:01 +0000332
Chris Lattner2f7c9632001-06-06 20:29:01 +0000333<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000334 <li>Named values are represented as a string of characters with their prefix.
335 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
336 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000337 Identifiers which require other characters in their names can be surrounded
Reid Spencerb23b65f2007-08-07 14:34:28 +0000338 with quotes. In this way, anything except a <tt>&quot;</tt> character can
339 be used in a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000340
Reid Spencerb23b65f2007-08-07 14:34:28 +0000341 <li>Unnamed values are represented as an unsigned numeric value with their
342 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000343
Reid Spencer8f08d802004-12-09 18:02:53 +0000344 <li>Constants, which are described in a <a href="#constants">section about
345 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000346</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000347
Reid Spencerb23b65f2007-08-07 14:34:28 +0000348<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000349don't need to worry about name clashes with reserved words, and the set of
350reserved words may be expanded in the future without penalty. Additionally,
351unnamed identifiers allow a compiler to quickly come up with a temporary
352variable without having to avoid symbol table conflicts.</p>
353
Chris Lattner48b383b02003-11-25 01:02:51 +0000354<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000355languages. There are keywords for different opcodes
356('<tt><a href="#i_add">add</a></tt>',
357 '<tt><a href="#i_bitcast">bitcast</a></tt>',
358 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000359href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000360and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000361none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000362
363<p>Here is an example of LLVM code to multiply the integer variable
364'<tt>%X</tt>' by 8:</p>
365
Misha Brukman76307852003-11-08 01:05:38 +0000366<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000367
Bill Wendling3716c5d2007-05-29 09:04:49 +0000368<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000369<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000370%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000371</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000372</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000373
Misha Brukman76307852003-11-08 01:05:38 +0000374<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000375
Bill Wendling3716c5d2007-05-29 09:04:49 +0000376<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000377<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000378%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000379</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000380</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000381
Misha Brukman76307852003-11-08 01:05:38 +0000382<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000383
Bill Wendling3716c5d2007-05-29 09:04:49 +0000384<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000385<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000386<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
387<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
388%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000389</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000390</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000391
Chris Lattner48b383b02003-11-25 01:02:51 +0000392<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
393important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000394
Chris Lattner2f7c9632001-06-06 20:29:01 +0000395<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000396
397 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
398 line.</li>
399
400 <li>Unnamed temporaries are created when the result of a computation is not
401 assigned to a named value.</li>
402
Misha Brukman76307852003-11-08 01:05:38 +0000403 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000404
Misha Brukman76307852003-11-08 01:05:38 +0000405</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000406
John Criswell02fdc6f2005-05-12 16:52:32 +0000407<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000408demonstrating instructions, we will follow an instruction with a comment that
409defines the type and name of value produced. Comments are shown in italic
410text.</p>
411
Misha Brukman76307852003-11-08 01:05:38 +0000412</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000413
414<!-- *********************************************************************** -->
415<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
416<!-- *********************************************************************** -->
417
418<!-- ======================================================================= -->
419<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
420</div>
421
422<div class="doc_text">
423
424<p>LLVM programs are composed of "Module"s, each of which is a
425translation unit of the input programs. Each module consists of
426functions, global variables, and symbol table entries. Modules may be
427combined together with the LLVM linker, which merges function (and
428global variable) definitions, resolves forward declarations, and merges
429symbol table entries. Here is an example of the "hello world" module:</p>
430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000431<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000432<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000433<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
434 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000435
436<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000437<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000438
439<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000440define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000441 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000442 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000443 href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000444
445 <i>; Call puts function to write out the string to stdout...</i>
446 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000447 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000448 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000449 href="#i_ret">ret</a> i32 0<br>}<br>
450</pre>
451</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000452
453<p>This example is made up of a <a href="#globalvars">global variable</a>
454named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
455function, and a <a href="#functionstructure">function definition</a>
456for "<tt>main</tt>".</p>
457
Chris Lattnerd79749a2004-12-09 16:36:40 +0000458<p>In general, a module is made up of a list of global values,
459where both functions and global variables are global values. Global values are
460represented by a pointer to a memory location (in this case, a pointer to an
461array of char, and a pointer to a function), and have one of the following <a
462href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000463
Chris Lattnerd79749a2004-12-09 16:36:40 +0000464</div>
465
466<!-- ======================================================================= -->
467<div class="doc_subsection">
468 <a name="linkage">Linkage Types</a>
469</div>
470
471<div class="doc_text">
472
473<p>
474All Global Variables and Functions have one of the following types of linkage:
475</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000476
477<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000478
Dale Johannesen4188aad2008-05-23 23:13:41 +0000479 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000480
481 <dd>Global values with internal linkage are only directly accessible by
482 objects in the current module. In particular, linking code into a module with
483 an internal global value may cause the internal to be renamed as necessary to
484 avoid collisions. Because the symbol is internal to the module, all
485 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000486 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000487 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000488
Chris Lattner6af02f32004-12-09 16:11:40 +0000489 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000490
Chris Lattnere20b4702007-01-14 06:51:48 +0000491 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
492 the same name when linkage occurs. This is typically used to implement
493 inline functions, templates, or other code which must be generated in each
494 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
495 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000496 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000497
Dale Johannesen4188aad2008-05-23 23:13:41 +0000498 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
499
500 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
501 linkage, except that unreferenced <tt>common</tt> globals may not be
502 discarded. This is used for globals that may be emitted in multiple
503 translation units, but that are not guaranteed to be emitted into every
504 translation unit that uses them. One example of this is tentative
505 definitions in C, such as "<tt>int X;</tt>" at global scope.
506 </dd>
507
Chris Lattner6af02f32004-12-09 16:11:40 +0000508 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000509
Dale Johannesen4188aad2008-05-23 23:13:41 +0000510 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
511 that some targets may choose to emit different assembly sequences for them
512 for target-dependent reasons. This is used for globals that are declared
513 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000514 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000515
Chris Lattner6af02f32004-12-09 16:11:40 +0000516 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000517
518 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
519 pointer to array type. When two global variables with appending linkage are
520 linked together, the two global arrays are appended together. This is the
521 LLVM, typesafe, equivalent of having the system linker append together
522 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000523 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000524
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000525 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000526 <dd>The semantics of this linkage follow the ELF object file model: the
527 symbol is weak until linked, if not linked, the symbol becomes null instead
528 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000529 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000530
Chris Lattner6af02f32004-12-09 16:11:40 +0000531 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000532
533 <dd>If none of the above identifiers are used, the global is externally
534 visible, meaning that it participates in linkage and can be used to resolve
535 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000536 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000537</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000538
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000539 <p>
540 The next two types of linkage are targeted for Microsoft Windows platform
541 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000542 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000543 </p>
544
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000545 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000546 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
547
548 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
549 or variable via a global pointer to a pointer that is set up by the DLL
550 exporting the symbol. On Microsoft Windows targets, the pointer name is
551 formed by combining <code>_imp__</code> and the function or variable name.
552 </dd>
553
554 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
555
556 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
557 pointer to a pointer in a DLL, so that it can be referenced with the
558 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
559 name is formed by combining <code>_imp__</code> and the function or variable
560 name.
561 </dd>
562
Chris Lattner6af02f32004-12-09 16:11:40 +0000563</dl>
564
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000565<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000566variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
567variable and was linked with this one, one of the two would be renamed,
568preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
569external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000570outside of the current module.</p>
571<p>It is illegal for a function <i>declaration</i>
572to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000573or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000574<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
575linkages.
Chris Lattner6af02f32004-12-09 16:11:40 +0000576</div>
577
578<!-- ======================================================================= -->
579<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000580 <a name="callingconv">Calling Conventions</a>
581</div>
582
583<div class="doc_text">
584
585<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
586and <a href="#i_invoke">invokes</a> can all have an optional calling convention
587specified for the call. The calling convention of any pair of dynamic
588caller/callee must match, or the behavior of the program is undefined. The
589following calling conventions are supported by LLVM, and more may be added in
590the future:</p>
591
592<dl>
593 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
594
595 <dd>This calling convention (the default if no other calling convention is
596 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000597 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000598 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000599 </dd>
600
601 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
602
603 <dd>This calling convention attempts to make calls as fast as possible
604 (e.g. by passing things in registers). This calling convention allows the
605 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000606 without having to conform to an externally specified ABI (Application Binary
607 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000608 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
609 supported. This calling convention does not support varargs and requires the
610 prototype of all callees to exactly match the prototype of the function
611 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000612 </dd>
613
614 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
615
616 <dd>This calling convention attempts to make code in the caller as efficient
617 as possible under the assumption that the call is not commonly executed. As
618 such, these calls often preserve all registers so that the call does not break
619 any live ranges in the caller side. This calling convention does not support
620 varargs and requires the prototype of all callees to exactly match the
621 prototype of the function definition.
622 </dd>
623
Chris Lattner573f64e2005-05-07 01:46:40 +0000624 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000625
626 <dd>Any calling convention may be specified by number, allowing
627 target-specific calling conventions to be used. Target specific calling
628 conventions start at 64.
629 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000630</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000631
632<p>More calling conventions can be added/defined on an as-needed basis, to
633support pascal conventions or any other well-known target-independent
634convention.</p>
635
636</div>
637
638<!-- ======================================================================= -->
639<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000640 <a name="visibility">Visibility Styles</a>
641</div>
642
643<div class="doc_text">
644
645<p>
646All Global Variables and Functions have one of the following visibility styles:
647</p>
648
649<dl>
650 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
651
Chris Lattner67c37d12008-08-05 18:29:16 +0000652 <dd>On targets that use the ELF object file format, default visibility means
653 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000654 modules and, in shared libraries, means that the declared entity may be
655 overridden. On Darwin, default visibility means that the declaration is
656 visible to other modules. Default visibility corresponds to "external
657 linkage" in the language.
658 </dd>
659
660 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
661
662 <dd>Two declarations of an object with hidden visibility refer to the same
663 object if they are in the same shared object. Usually, hidden visibility
664 indicates that the symbol will not be placed into the dynamic symbol table,
665 so no other module (executable or shared library) can reference it
666 directly.
667 </dd>
668
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000669 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
670
671 <dd>On ELF, protected visibility indicates that the symbol will be placed in
672 the dynamic symbol table, but that references within the defining module will
673 bind to the local symbol. That is, the symbol cannot be overridden by another
674 module.
675 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000676</dl>
677
678</div>
679
680<!-- ======================================================================= -->
681<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000682 <a name="globalvars">Global Variables</a>
683</div>
684
685<div class="doc_text">
686
Chris Lattner5d5aede2005-02-12 19:30:21 +0000687<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000688instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000689an explicit section to be placed in, and may have an optional explicit alignment
690specified. A variable may be defined as "thread_local", which means that it
691will not be shared by threads (each thread will have a separated copy of the
692variable). A variable may be defined as a global "constant," which indicates
693that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000694optimization, allowing the global data to be placed in the read-only section of
695an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000696cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000697
698<p>
699LLVM explicitly allows <em>declarations</em> of global variables to be marked
700constant, even if the final definition of the global is not. This capability
701can be used to enable slightly better optimization of the program, but requires
702the language definition to guarantee that optimizations based on the
703'constantness' are valid for the translation units that do not include the
704definition.
705</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000706
707<p>As SSA values, global variables define pointer values that are in
708scope (i.e. they dominate) all basic blocks in the program. Global
709variables always define a pointer to their "content" type because they
710describe a region of memory, and all memory objects in LLVM are
711accessed through pointers.</p>
712
Christopher Lamb308121c2007-12-11 09:31:00 +0000713<p>A global variable may be declared to reside in a target-specifc numbered
714address space. For targets that support them, address spaces may affect how
715optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000716the variable. The default address space is zero. The address space qualifier
717must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000718
Chris Lattner662c8722005-11-12 00:45:07 +0000719<p>LLVM allows an explicit section to be specified for globals. If the target
720supports it, it will emit globals to the section specified.</p>
721
Chris Lattner54611b42005-11-06 08:02:57 +0000722<p>An explicit alignment may be specified for a global. If not present, or if
723the alignment is set to zero, the alignment of the global is set by the target
724to whatever it feels convenient. If an explicit alignment is specified, the
725global is forced to have at least that much alignment. All alignments must be
726a power of 2.</p>
727
Christopher Lamb308121c2007-12-11 09:31:00 +0000728<p>For example, the following defines a global in a numbered address space with
729an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000730
Bill Wendling3716c5d2007-05-29 09:04:49 +0000731<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000732<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000733@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000734</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000735</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000736
Chris Lattner6af02f32004-12-09 16:11:40 +0000737</div>
738
739
740<!-- ======================================================================= -->
741<div class="doc_subsection">
742 <a name="functionstructure">Functions</a>
743</div>
744
745<div class="doc_text">
746
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000747<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
748an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000749<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000750<a href="#callingconv">calling convention</a>, a return type, an optional
751<a href="#paramattrs">parameter attribute</a> for the return type, a function
752name, a (possibly empty) argument list (each with optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000753<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patelcaacdba2008-09-04 23:05:13 +0000754optional alignment, an optional <a href="#gc">garbage collector name</a>,
755an optional <a href="#notes">function notes</a>, an
Gordon Henriksen71183b62007-12-10 03:18:06 +0000756opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000757
758LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
759optional <a href="#linkage">linkage type</a>, an optional
760<a href="#visibility">visibility style</a>, an optional
761<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000762<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000763name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000764<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000765
Chris Lattner67c37d12008-08-05 18:29:16 +0000766<p>A function definition contains a list of basic blocks, forming the CFG
767(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000768the function. Each basic block may optionally start with a label (giving the
769basic block a symbol table entry), contains a list of instructions, and ends
770with a <a href="#terminators">terminator</a> instruction (such as a branch or
771function return).</p>
772
Chris Lattnera59fb102007-06-08 16:52:14 +0000773<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner6af02f32004-12-09 16:11:40 +0000774executed on entrance to the function, and it is not allowed to have predecessor
775basic blocks (i.e. there can not be any branches to the entry block of a
776function). Because the block can have no predecessors, it also cannot have any
777<a href="#i_phi">PHI nodes</a>.</p>
778
Chris Lattner662c8722005-11-12 00:45:07 +0000779<p>LLVM allows an explicit section to be specified for functions. If the target
780supports it, it will emit functions to the section specified.</p>
781
Chris Lattner54611b42005-11-06 08:02:57 +0000782<p>An explicit alignment may be specified for a function. If not present, or if
783the alignment is set to zero, the alignment of the function is set by the target
784to whatever it feels convenient. If an explicit alignment is specified, the
785function is forced to have at least that much alignment. All alignments must be
786a power of 2.</p>
787
Chris Lattner6af02f32004-12-09 16:11:40 +0000788</div>
789
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000790
791<!-- ======================================================================= -->
792<div class="doc_subsection">
793 <a name="aliasstructure">Aliases</a>
794</div>
795<div class="doc_text">
796 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000797 function, global variable, another alias or bitcast of global value). Aliases
798 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000799 optional <a href="#visibility">visibility style</a>.</p>
800
801 <h5>Syntax:</h5>
802
Bill Wendling3716c5d2007-05-29 09:04:49 +0000803<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000804<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000805@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000806</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000807</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000808
809</div>
810
811
812
Chris Lattner91c15c42006-01-23 23:23:47 +0000813<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000814<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
815<div class="doc_text">
816 <p>The return type and each parameter of a function type may have a set of
817 <i>parameter attributes</i> associated with them. Parameter attributes are
818 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000819 a function. Parameter attributes are considered to be part of the function,
820 not of the function type, so functions with different parameter attributes
821 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000822
Reid Spencercf7ebf52007-01-15 18:27:39 +0000823 <p>Parameter attributes are simple keywords that follow the type specified. If
824 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000825 example:</p>
826
827<div class="doc_code">
828<pre>
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000829declare i32 @printf(i8* noalias , ...) nounwind
830declare i32 @atoi(i8*) nounwind readonly
Bill Wendling3716c5d2007-05-29 09:04:49 +0000831</pre>
832</div>
833
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000834 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
835 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000836
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000837 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000838 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000839 <dt><tt>zeroext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000840 <dd>This indicates that the parameter should be zero extended just before
841 a call to this function.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000842
Reid Spencer314e1cb2007-07-19 23:13:04 +0000843 <dt><tt>signext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000844 <dd>This indicates that the parameter should be sign extended just before
845 a call to this function.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000846
Anton Korobeynikove8166852007-01-28 14:30:45 +0000847 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000848 <dd>This indicates that this parameter or return value should be treated
849 in a special target-dependent fashion during while emitting code for a
850 function call or return (usually, by putting it in a register as opposed
851 to memory; in some places it is used to distinguish between two different
852 kinds of registers). Use of this attribute is target-specific</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000853
854 <dt><tt>byval</tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000855 <dd>This indicates that the pointer parameter should really be passed by
856 value to the function. The attribute implies that a hidden copy of the
857 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000858 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000859 pointer arguments. It is generally used to pass structs and arrays by
860 value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000861
Anton Korobeynikove8166852007-01-28 14:30:45 +0000862 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000863 <dd>This indicates that the pointer parameter specifies the address of a
864 structure that is the return value of the function in the source program.
Duncan Sandsc572c1e2008-03-17 12:17:41 +0000865 Loads and stores to the structure are assumed not to trap.
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000866 May only be applied to the first parameter.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000867
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000868 <dt><tt>noalias</tt></dt>
Owen Anderson61101282008-02-18 04:09:01 +0000869 <dd>This indicates that the parameter does not alias any global or any other
870 parameter. The caller is responsible for ensuring that this is the case,
871 usually by placing the value in a stack allocation.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000872
Reid Spencer9d1700e2007-03-22 02:18:56 +0000873 <dt><tt>noreturn</tt></dt>
874 <dd>This function attribute indicates that the function never returns. This
875 indicates to LLVM that every call to this function should be treated as if
876 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000877
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000878 <dt><tt>nounwind</tt></dt>
Duncan Sandsc572c1e2008-03-17 12:17:41 +0000879 <dd>This function attribute indicates that no exceptions unwind out of the
880 function. Usually this is because the function makes no use of exceptions,
881 but it may also be that the function catches any exceptions thrown when
882 executing it.</dd>
883
Duncan Sands27e91592007-07-27 19:57:41 +0000884 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000885 <dd>This indicates that the pointer parameter can be excised using the
Duncan Sands27e91592007-07-27 19:57:41 +0000886 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsa89a1132007-11-22 20:23:04 +0000887 <dt><tt>readonly</tt></dt>
Duncan Sands730a3262007-11-14 21:14:02 +0000888 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsa89a1132007-11-22 20:23:04 +0000889 except for producing a return value or throwing an exception. The value
890 returned must only depend on the function arguments and/or global variables.
891 It may use values obtained by dereferencing pointers.</dd>
892 <dt><tt>readnone</tt></dt>
893 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sands730a3262007-11-14 21:14:02 +0000894 function, but in addition it is not allowed to dereference any pointer arguments
895 or global variables.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000896 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000897
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000898</div>
899
900<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000901<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000902 <a name="gc">Garbage Collector Names</a>
903</div>
904
905<div class="doc_text">
906<p>Each function may specify a garbage collector name, which is simply a
907string.</p>
908
909<div class="doc_code"><pre
910>define void @f() gc "name" { ...</pre></div>
911
912<p>The compiler declares the supported values of <i>name</i>. Specifying a
913collector which will cause the compiler to alter its output in order to support
914the named garbage collection algorithm.</p>
915</div>
916
917<!-- ======================================================================= -->
918<div class="doc_subsection">
Devang Patelcaacdba2008-09-04 23:05:13 +0000919 <a name="notes">Function Notes</a>
920</div>
921
922<div class="doc_text">
Devang Patel8af98cd2008-09-04 23:10:26 +0000923<p>The function definition may list function notes which are used by
924various passes.</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000925
926<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000927<pre>
928define void @f() notes(inline=Always) { ... }
929define void @f() notes(inline=Always,opt-size) { ... }
930define void @f() notes(inline=Never,opt-size) { ... }
931define void @f() notes(opt-size) { ... }
932</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000933</div>
934
Bill Wendlingb175fa42008-09-07 10:26:33 +0000935<dl>
936<dt><tt>inline=Always</tt></dt>
937<dd>This note requests inliner to inline this function irrespective of inlining
938size threshold for this function.</dd>
939
940<dt><tt>inline=Never</tt></dt>
941<dd>This note requests inliner to never inline this function in any situation.
942This note may not be used together with <tt>inline=Always</tt> note.</dd>
943
944<dt><tt>opt-size</tt></dt>
945<dd>This note suggests optimization passes and code generator passes to make
946choices that help reduce code size.</dd>
947
948</dl>
949
950<p>Any notes that are not documented here are considered invalid notes.</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000951</div>
952
953<!-- ======================================================================= -->
954<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000955 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000956</div>
957
958<div class="doc_text">
959<p>
960Modules may contain "module-level inline asm" blocks, which corresponds to the
961GCC "file scope inline asm" blocks. These blocks are internally concatenated by
962LLVM and treated as a single unit, but may be separated in the .ll file if
963desired. The syntax is very simple:
964</p>
965
Bill Wendling3716c5d2007-05-29 09:04:49 +0000966<div class="doc_code">
967<pre>
968module asm "inline asm code goes here"
969module asm "more can go here"
970</pre>
971</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000972
973<p>The strings can contain any character by escaping non-printable characters.
974 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
975 for the number.
976</p>
977
978<p>
979 The inline asm code is simply printed to the machine code .s file when
980 assembly code is generated.
981</p>
982</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000983
Reid Spencer50c723a2007-02-19 23:54:10 +0000984<!-- ======================================================================= -->
985<div class="doc_subsection">
986 <a name="datalayout">Data Layout</a>
987</div>
988
989<div class="doc_text">
990<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000991data is to be laid out in memory. The syntax for the data layout is simply:</p>
992<pre> target datalayout = "<i>layout specification</i>"</pre>
993<p>The <i>layout specification</i> consists of a list of specifications
994separated by the minus sign character ('-'). Each specification starts with a
995letter and may include other information after the letter to define some
996aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000997<dl>
998 <dt><tt>E</tt></dt>
999 <dd>Specifies that the target lays out data in big-endian form. That is, the
1000 bits with the most significance have the lowest address location.</dd>
1001 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +00001002 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +00001003 the bits with the least significance have the lowest address location.</dd>
1004 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1005 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1006 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1007 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1008 too.</dd>
1009 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1010 <dd>This specifies the alignment for an integer type of a given bit
1011 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1012 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1013 <dd>This specifies the alignment for a vector type of a given bit
1014 <i>size</i>.</dd>
1015 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1016 <dd>This specifies the alignment for a floating point type of a given bit
1017 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1018 (double).</dd>
1019 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1020 <dd>This specifies the alignment for an aggregate type of a given bit
1021 <i>size</i>.</dd>
1022</dl>
1023<p>When constructing the data layout for a given target, LLVM starts with a
1024default set of specifications which are then (possibly) overriden by the
1025specifications in the <tt>datalayout</tt> keyword. The default specifications
1026are given in this list:</p>
1027<ul>
1028 <li><tt>E</tt> - big endian</li>
1029 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1030 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1031 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1032 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1033 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +00001034 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +00001035 alignment of 64-bits</li>
1036 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1037 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1038 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1039 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1040 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1041</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +00001042<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer50c723a2007-02-19 23:54:10 +00001043following rules:
1044<ol>
1045 <li>If the type sought is an exact match for one of the specifications, that
1046 specification is used.</li>
1047 <li>If no match is found, and the type sought is an integer type, then the
1048 smallest integer type that is larger than the bitwidth of the sought type is
1049 used. If none of the specifications are larger than the bitwidth then the the
1050 largest integer type is used. For example, given the default specifications
1051 above, the i7 type will use the alignment of i8 (next largest) while both
1052 i65 and i256 will use the alignment of i64 (largest specified).</li>
1053 <li>If no match is found, and the type sought is a vector type, then the
1054 largest vector type that is smaller than the sought vector type will be used
1055 as a fall back. This happens because <128 x double> can be implemented in
1056 terms of 64 <2 x double>, for example.</li>
1057</ol>
1058</div>
Chris Lattner6af02f32004-12-09 16:11:40 +00001059
Chris Lattner2f7c9632001-06-06 20:29:01 +00001060<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001061<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1062<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +00001063
Misha Brukman76307852003-11-08 01:05:38 +00001064<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +00001065
Misha Brukman76307852003-11-08 01:05:38 +00001066<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +00001067intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +00001068optimizations to be performed on the intermediate representation directly,
1069without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +00001070extra analyses on the side before the transformation. A strong type
1071system makes it easier to read the generated code and enables novel
1072analyses and transformations that are not feasible to perform on normal
1073three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +00001074
1075</div>
1076
Chris Lattner2f7c9632001-06-06 20:29:01 +00001077<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +00001078<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +00001079Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001080<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +00001081<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +00001082classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +00001083
1084<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +00001085 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001086 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +00001087 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +00001088 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +00001089 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +00001090 </tr>
1091 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +00001092 <td><a href="#t_floating">floating point</a></td>
1093 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +00001094 </tr>
1095 <tr>
1096 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +00001097 <td><a href="#t_integer">integer</a>,
1098 <a href="#t_floating">floating point</a>,
1099 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +00001100 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +00001101 <a href="#t_struct">structure</a>,
1102 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +00001103 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00001104 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +00001105 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +00001106 <tr>
1107 <td><a href="#t_primitive">primitive</a></td>
1108 <td><a href="#t_label">label</a>,
1109 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +00001110 <a href="#t_floating">floating point</a>.</td>
1111 </tr>
1112 <tr>
1113 <td><a href="#t_derived">derived</a></td>
1114 <td><a href="#t_integer">integer</a>,
1115 <a href="#t_array">array</a>,
1116 <a href="#t_function">function</a>,
1117 <a href="#t_pointer">pointer</a>,
1118 <a href="#t_struct">structure</a>,
1119 <a href="#t_pstruct">packed structure</a>,
1120 <a href="#t_vector">vector</a>,
1121 <a href="#t_opaque">opaque</a>.
1122 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +00001123 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +00001124</table>
Misha Brukmanc501f552004-03-01 17:47:27 +00001125
Chris Lattner48b383b02003-11-25 01:02:51 +00001126<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1127most important. Values of these types are the only ones which can be
1128produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +00001129instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +00001130</div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001131
Chris Lattner2f7c9632001-06-06 20:29:01 +00001132<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +00001133<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +00001134
Chris Lattner7824d182008-01-04 04:32:38 +00001135<div class="doc_text">
1136<p>The primitive types are the fundamental building blocks of the LLVM
1137system.</p>
1138
Chris Lattner43542b32008-01-04 04:34:14 +00001139</div>
1140
Chris Lattner7824d182008-01-04 04:32:38 +00001141<!-- _______________________________________________________________________ -->
1142<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1143
1144<div class="doc_text">
1145 <table>
1146 <tbody>
1147 <tr><th>Type</th><th>Description</th></tr>
1148 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1149 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1150 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1151 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1152 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1153 </tbody>
1154 </table>
1155</div>
1156
1157<!-- _______________________________________________________________________ -->
1158<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1159
1160<div class="doc_text">
1161<h5>Overview:</h5>
1162<p>The void type does not represent any value and has no size.</p>
1163
1164<h5>Syntax:</h5>
1165
1166<pre>
1167 void
1168</pre>
1169</div>
1170
1171<!-- _______________________________________________________________________ -->
1172<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1173
1174<div class="doc_text">
1175<h5>Overview:</h5>
1176<p>The label type represents code labels.</p>
1177
1178<h5>Syntax:</h5>
1179
1180<pre>
1181 label
1182</pre>
1183</div>
1184
1185
1186<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001187<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001188
Misha Brukman76307852003-11-08 01:05:38 +00001189<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +00001190
Chris Lattner48b383b02003-11-25 01:02:51 +00001191<p>The real power in LLVM comes from the derived types in the system.
1192This is what allows a programmer to represent arrays, functions,
1193pointers, and other useful types. Note that these derived types may be
1194recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001195
Misha Brukman76307852003-11-08 01:05:38 +00001196</div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001197
Chris Lattner2f7c9632001-06-06 20:29:01 +00001198<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +00001199<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1200
1201<div class="doc_text">
1202
1203<h5>Overview:</h5>
1204<p>The integer type is a very simple derived type that simply specifies an
1205arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12062^23-1 (about 8 million) can be specified.</p>
1207
1208<h5>Syntax:</h5>
1209
1210<pre>
1211 iN
1212</pre>
1213
1214<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1215value.</p>
1216
1217<h5>Examples:</h5>
1218<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +00001219 <tbody>
1220 <tr>
1221 <td><tt>i1</tt></td>
1222 <td>a single-bit integer.</td>
1223 </tr><tr>
1224 <td><tt>i32</tt></td>
1225 <td>a 32-bit integer.</td>
1226 </tr><tr>
1227 <td><tt>i1942652</tt></td>
1228 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +00001229 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +00001230 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +00001231</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001232</div>
Reid Spencer138249b2007-05-16 18:44:01 +00001233
1234<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001235<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001236
Misha Brukman76307852003-11-08 01:05:38 +00001237<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +00001238
Chris Lattner2f7c9632001-06-06 20:29:01 +00001239<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +00001240
Misha Brukman76307852003-11-08 01:05:38 +00001241<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +00001242sequentially in memory. The array type requires a size (number of
1243elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001244
Chris Lattner590645f2002-04-14 06:13:44 +00001245<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +00001246
1247<pre>
1248 [&lt;# elements&gt; x &lt;elementtype&gt;]
1249</pre>
1250
John Criswell02fdc6f2005-05-12 16:52:32 +00001251<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +00001252be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001253
Chris Lattner590645f2002-04-14 06:13:44 +00001254<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001255<table class="layout">
1256 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +00001257 <td class="left"><tt>[40 x i32]</tt></td>
1258 <td class="left">Array of 40 32-bit integer values.</td>
1259 </tr>
1260 <tr class="layout">
1261 <td class="left"><tt>[41 x i32]</tt></td>
1262 <td class="left">Array of 41 32-bit integer values.</td>
1263 </tr>
1264 <tr class="layout">
1265 <td class="left"><tt>[4 x i8]</tt></td>
1266 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001267 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001268</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001269<p>Here are some examples of multidimensional arrays:</p>
1270<table class="layout">
1271 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +00001272 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1273 <td class="left">3x4 array of 32-bit integer values.</td>
1274 </tr>
1275 <tr class="layout">
1276 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1277 <td class="left">12x10 array of single precision floating point values.</td>
1278 </tr>
1279 <tr class="layout">
1280 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1281 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001282 </tr>
1283</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +00001284
John Criswell4c0cf7f2005-10-24 16:17:18 +00001285<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1286length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +00001287LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1288As a special case, however, zero length arrays are recognized to be variable
1289length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00001290type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +00001291
Misha Brukman76307852003-11-08 01:05:38 +00001292</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001293
Chris Lattner2f7c9632001-06-06 20:29:01 +00001294<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001295<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001296<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +00001297
Chris Lattner2f7c9632001-06-06 20:29:01 +00001298<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001299
Chris Lattner48b383b02003-11-25 01:02:51 +00001300<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +00001301consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +00001302return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel9c1f8b12008-03-24 20:52:42 +00001303If the return type is a struct type then all struct elements must be of first
Chris Lattnerda508ac2008-04-23 04:59:35 +00001304class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +00001305
Chris Lattner2f7c9632001-06-06 20:29:01 +00001306<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001307
1308<pre>
1309 &lt;returntype list&gt; (&lt;parameter list&gt;)
1310</pre>
1311
John Criswell4c0cf7f2005-10-24 16:17:18 +00001312<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukman20f9a622004-08-12 20:16:08 +00001313specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +00001314which indicates that the function takes a variable number of arguments.
1315Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +00001316 href="#int_varargs">variable argument handling intrinsic</a> functions.
1317'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1318<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001319
Chris Lattner2f7c9632001-06-06 20:29:01 +00001320<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001321<table class="layout">
1322 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +00001323 <td class="left"><tt>i32 (i32)</tt></td>
1324 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001325 </td>
Reid Spencer58c08712006-12-31 07:18:34 +00001326 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +00001327 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +00001328 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +00001329 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1330 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00001331 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +00001332 <tt>float</tt>.
1333 </td>
1334 </tr><tr class="layout">
1335 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1336 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +00001337 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +00001338 which returns an integer. This is the signature for <tt>printf</tt> in
1339 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001340 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +00001341 </tr><tr class="layout">
1342 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel8dec6c22008-03-24 18:10:52 +00001343 <td class="left">A function taking an <tt>i32></tt>, returning two
1344 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +00001345 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001346 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001347</table>
Misha Brukmanc501f552004-03-01 17:47:27 +00001348
Misha Brukman76307852003-11-08 01:05:38 +00001349</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001350<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001351<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001352<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00001353<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001354<p>The structure type is used to represent a collection of data members
1355together in memory. The packing of the field types is defined to match
1356the ABI of the underlying processor. The elements of a structure may
1357be any type that has a size.</p>
1358<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1359and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1360field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1361instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001362<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001363<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001364<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001365<table class="layout">
1366 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +00001367 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1368 <td class="left">A triple of three <tt>i32</tt> values</td>
1369 </tr><tr class="layout">
1370 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1371 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1372 second element is a <a href="#t_pointer">pointer</a> to a
1373 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1374 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001375 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001376</table>
Misha Brukman76307852003-11-08 01:05:38 +00001377</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001378
Chris Lattner2f7c9632001-06-06 20:29:01 +00001379<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +00001380<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1381</div>
1382<div class="doc_text">
1383<h5>Overview:</h5>
1384<p>The packed structure type is used to represent a collection of data members
1385together in memory. There is no padding between fields. Further, the alignment
1386of a packed structure is 1 byte. The elements of a packed structure may
1387be any type that has a size.</p>
1388<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1389and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1390field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1391instruction.</p>
1392<h5>Syntax:</h5>
1393<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1394<h5>Examples:</h5>
1395<table class="layout">
1396 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +00001397 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1398 <td class="left">A triple of three <tt>i32</tt> values</td>
1399 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +00001400 <td class="left">
1401<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +00001402 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1403 second element is a <a href="#t_pointer">pointer</a> to a
1404 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1405 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +00001406 </tr>
1407</table>
1408</div>
1409
1410<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001411<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001412<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +00001413<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001414<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +00001415reference to another object, which must live in memory. Pointer types may have
1416an optional address space attribute defining the target-specific numbered
1417address space where the pointed-to object resides. The default address space is
1418zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +00001419<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001420<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +00001421<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001422<table class="layout">
1423 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +00001424 <td class="left"><tt>[4x i32]*</tt></td>
1425 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1426 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1427 </tr>
1428 <tr class="layout">
1429 <td class="left"><tt>i32 (i32 *) *</tt></td>
1430 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00001431 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +00001432 <tt>i32</tt>.</td>
1433 </tr>
1434 <tr class="layout">
1435 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1436 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1437 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001438 </tr>
Misha Brukman76307852003-11-08 01:05:38 +00001439</table>
Misha Brukman76307852003-11-08 01:05:38 +00001440</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001441
Chris Lattnerc8cb6952004-08-12 19:12:28 +00001442<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +00001443<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001444<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +00001445
Chris Lattnerc8cb6952004-08-12 19:12:28 +00001446<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +00001447
Reid Spencer404a3252007-02-15 03:07:05 +00001448<p>A vector type is a simple derived type that represents a vector
1449of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +00001450are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +00001451A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +00001452elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +00001453of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +00001454considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +00001455
Chris Lattnerc8cb6952004-08-12 19:12:28 +00001456<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +00001457
1458<pre>
1459 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1460</pre>
1461
John Criswell4a3327e2005-05-13 22:25:59 +00001462<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +00001463be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +00001464
Chris Lattnerc8cb6952004-08-12 19:12:28 +00001465<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +00001466
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001467<table class="layout">
1468 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +00001469 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1470 <td class="left">Vector of 4 32-bit integer values.</td>
1471 </tr>
1472 <tr class="layout">
1473 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1474 <td class="left">Vector of 8 32-bit floating-point values.</td>
1475 </tr>
1476 <tr class="layout">
1477 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1478 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +00001479 </tr>
1480</table>
Misha Brukman76307852003-11-08 01:05:38 +00001481</div>
1482
Chris Lattner37b6b092005-04-25 17:34:15 +00001483<!-- _______________________________________________________________________ -->
1484<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1485<div class="doc_text">
1486
1487<h5>Overview:</h5>
1488
1489<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +00001490corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +00001491In LLVM, opaque types can eventually be resolved to any type (not just a
1492structure type).</p>
1493
1494<h5>Syntax:</h5>
1495
1496<pre>
1497 opaque
1498</pre>
1499
1500<h5>Examples:</h5>
1501
1502<table class="layout">
1503 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +00001504 <td class="left"><tt>opaque</tt></td>
1505 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +00001506 </tr>
1507</table>
1508</div>
1509
1510
Chris Lattner74d3f822004-12-09 17:30:23 +00001511<!-- *********************************************************************** -->
1512<div class="doc_section"> <a name="constants">Constants</a> </div>
1513<!-- *********************************************************************** -->
1514
1515<div class="doc_text">
1516
1517<p>LLVM has several different basic types of constants. This section describes
1518them all and their syntax.</p>
1519
1520</div>
1521
1522<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +00001523<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001524
1525<div class="doc_text">
1526
1527<dl>
1528 <dt><b>Boolean constants</b></dt>
1529
1530 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +00001531 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +00001532 </dd>
1533
1534 <dt><b>Integer constants</b></dt>
1535
Reid Spencer8f08d802004-12-09 18:02:53 +00001536 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +00001537 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +00001538 integer types.
1539 </dd>
1540
1541 <dt><b>Floating point constants</b></dt>
1542
1543 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1544 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +00001545 notation (see below). The assembler requires the exact decimal value of
1546 a floating-point constant. For example, the assembler accepts 1.25 but
1547 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1548 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +00001549
1550 <dt><b>Null pointer constants</b></dt>
1551
John Criswelldfe6a862004-12-10 15:51:16 +00001552 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +00001553 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1554
1555</dl>
1556
John Criswelldfe6a862004-12-10 15:51:16 +00001557<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +00001558of floating point constants. For example, the form '<tt>double
15590x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
15604.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +00001561(and the only time that they are generated by the disassembler) is when a
1562floating point constant must be emitted but it cannot be represented as a
1563decimal floating point number. For example, NaN's, infinities, and other
1564special values are represented in their IEEE hexadecimal format so that
1565assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001566
1567</div>
1568
1569<!-- ======================================================================= -->
1570<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1571</div>
1572
1573<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +00001574<p>Aggregate constants arise from aggregation of simple constants
1575and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001576
1577<dl>
1578 <dt><b>Structure constants</b></dt>
1579
1580 <dd>Structure constants are represented with notation similar to structure
1581 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +00001582 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1583 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner455fc8c2005-03-07 22:13:59 +00001584 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +00001585 types of elements must match those specified by the type.
1586 </dd>
1587
1588 <dt><b>Array constants</b></dt>
1589
1590 <dd>Array constants are represented with notation similar to array type
1591 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00001592 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +00001593 constants must have <a href="#t_array">array type</a>, and the number and
1594 types of elements must match those specified by the type.
1595 </dd>
1596
Reid Spencer404a3252007-02-15 03:07:05 +00001597 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +00001598
Reid Spencer404a3252007-02-15 03:07:05 +00001599 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +00001600 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00001601 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen5819f182007-04-22 01:17:39 +00001602 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +00001603 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +00001604 match those specified by the type.
1605 </dd>
1606
1607 <dt><b>Zero initialization</b></dt>
1608
1609 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1610 value to zero of <em>any</em> type, including scalar and aggregate types.
1611 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell4c0cf7f2005-10-24 16:17:18 +00001612 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +00001613 initializers.
1614 </dd>
1615</dl>
1616
1617</div>
1618
1619<!-- ======================================================================= -->
1620<div class="doc_subsection">
1621 <a name="globalconstants">Global Variable and Function Addresses</a>
1622</div>
1623
1624<div class="doc_text">
1625
1626<p>The addresses of <a href="#globalvars">global variables</a> and <a
1627href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +00001628constants. These constants are explicitly referenced when the <a
1629href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +00001630href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1631file:</p>
1632
Bill Wendling3716c5d2007-05-29 09:04:49 +00001633<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +00001634<pre>
Chris Lattner00538a12007-06-06 18:28:13 +00001635@X = global i32 17
1636@Y = global i32 42
1637@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +00001638</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001639</div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001640
1641</div>
1642
1643<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +00001644<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001645<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +00001646 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell4a3327e2005-05-13 22:25:59 +00001647 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +00001648 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001649
Reid Spencer641f5c92004-12-09 18:13:12 +00001650 <p>Undefined values indicate to the compiler that the program is well defined
1651 no matter what value is used, giving the compiler more freedom to optimize.
1652 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001653</div>
1654
1655<!-- ======================================================================= -->
1656<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1657</div>
1658
1659<div class="doc_text">
1660
1661<p>Constant expressions are used to allow expressions involving other constants
1662to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +00001663href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +00001664that does not have side effects (e.g. load and call are not supported). The
1665following is the syntax for constant expressions:</p>
1666
1667<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001668 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1669 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattnerc0f423a2007-01-15 01:54:13 +00001670 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +00001671
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001672 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1673 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattnerc0f423a2007-01-15 01:54:13 +00001674 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001675
1676 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1677 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattnerc0f423a2007-01-15 01:54:13 +00001678 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001679
1680 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1681 <dd>Truncate a floating point constant to another floating point type. The
1682 size of CST must be larger than the size of TYPE. Both types must be
1683 floating point.</dd>
1684
1685 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1686 <dd>Floating point extend a constant to another type. The size of CST must be
1687 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1688
Reid Spencer753163d2007-07-31 14:40:14 +00001689 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001690 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +00001691 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1692 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1693 of the same number of elements. If the value won't fit in the integer type,
1694 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001695
Reid Spencer51b07252006-11-09 23:03:26 +00001696 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001697 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +00001698 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1699 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1700 of the same number of elements. If the value won't fit in the integer type,
1701 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001702
Reid Spencer51b07252006-11-09 23:03:26 +00001703 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001704 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +00001705 constant. TYPE must be a scalar or vector floating point type. CST must be of
1706 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1707 of the same number of elements. If the value won't fit in the floating point
1708 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001709
Reid Spencer51b07252006-11-09 23:03:26 +00001710 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001711 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +00001712 constant. TYPE must be a scalar or vector floating point type. CST must be of
1713 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1714 of the same number of elements. If the value won't fit in the floating point
1715 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001716
Reid Spencer5b950642006-11-11 23:08:07 +00001717 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1718 <dd>Convert a pointer typed constant to the corresponding integer constant
1719 TYPE must be an integer type. CST must be of pointer type. The CST value is
1720 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1721
1722 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1723 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1724 pointer type. CST must be of integer type. The CST value is zero extended,
1725 truncated, or unchanged to make it fit in a pointer size. This one is
1726 <i>really</i> dangerous!</dd>
1727
1728 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001729 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1730 identical (same number of bits). The conversion is done as if the CST value
1731 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5b950642006-11-11 23:08:07 +00001732 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +00001733 vector types to any other type, as long as they have the same bit width. For
Dan Gohmanc05dca92008-09-08 16:45:59 +00001734 pointers it is only valid to cast to another pointer type. It is not valid
1735 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +00001736 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +00001737
1738 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1739
1740 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1741 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1742 instruction, the index list may have zero or more indexes, which are required
1743 to make sense for the type of "CSTPTR".</dd>
1744
Robert Bocchino7e97a6d2006-01-10 19:31:34 +00001745 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1746
1747 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +00001748 constants.</dd>
1749
1750 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1751 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1752
1753 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1754 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +00001755
Nate Begemand2195702008-05-12 19:01:56 +00001756 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1757 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1758
1759 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1760 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1761
Robert Bocchino7e97a6d2006-01-10 19:31:34 +00001762 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1763
1764 <dd>Perform the <a href="#i_extractelement">extractelement
1765 operation</a> on constants.
1766
Robert Bocchinof72fdfe2006-01-15 20:48:27 +00001767 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1768
1769 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +00001770 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +00001771
Chris Lattner016a0e52006-04-08 00:13:41 +00001772
1773 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1774
1775 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +00001776 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +00001777
Chris Lattner74d3f822004-12-09 17:30:23 +00001778 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1779
Reid Spencer641f5c92004-12-09 18:13:12 +00001780 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1781 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +00001782 binary</a> operations. The constraints on operands are the same as those for
1783 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +00001784 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +00001785</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +00001786</div>
Chris Lattnerb1652612004-03-08 16:49:10 +00001787
Chris Lattner2f7c9632001-06-06 20:29:01 +00001788<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +00001789<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1790<!-- *********************************************************************** -->
1791
1792<!-- ======================================================================= -->
1793<div class="doc_subsection">
1794<a name="inlineasm">Inline Assembler Expressions</a>
1795</div>
1796
1797<div class="doc_text">
1798
1799<p>
1800LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1801Module-Level Inline Assembly</a>) through the use of a special value. This
1802value represents the inline assembler as a string (containing the instructions
1803to emit), a list of operand constraints (stored as a string), and a flag that
1804indicates whether or not the inline asm expression has side effects. An example
1805inline assembler expression is:
1806</p>
1807
Bill Wendling3716c5d2007-05-29 09:04:49 +00001808<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +00001809<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001810i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +00001811</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001812</div>
Chris Lattner98f013c2006-01-25 23:47:57 +00001813
1814<p>
1815Inline assembler expressions may <b>only</b> be used as the callee operand of
1816a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1817</p>
1818
Bill Wendling3716c5d2007-05-29 09:04:49 +00001819<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +00001820<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001821%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +00001822</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001823</div>
Chris Lattner98f013c2006-01-25 23:47:57 +00001824
1825<p>
1826Inline asms with side effects not visible in the constraint list must be marked
1827as having side effects. This is done through the use of the
1828'<tt>sideeffect</tt>' keyword, like so:
1829</p>
1830
Bill Wendling3716c5d2007-05-29 09:04:49 +00001831<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +00001832<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001833call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +00001834</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00001835</div>
Chris Lattner98f013c2006-01-25 23:47:57 +00001836
1837<p>TODO: The format of the asm and constraints string still need to be
1838documented here. Constraints on what can be done (e.g. duplication, moving, etc
1839need to be documented).
1840</p>
1841
1842</div>
1843
1844<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001845<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1846<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +00001847
Misha Brukman76307852003-11-08 01:05:38 +00001848<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +00001849
Chris Lattner48b383b02003-11-25 01:02:51 +00001850<p>The LLVM instruction set consists of several different
1851classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +00001852instructions</a>, <a href="#binaryops">binary instructions</a>,
1853<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +00001854 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1855instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001856
Misha Brukman76307852003-11-08 01:05:38 +00001857</div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001858
Chris Lattner2f7c9632001-06-06 20:29:01 +00001859<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001860<div class="doc_subsection"> <a name="terminators">Terminator
1861Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001862
Misha Brukman76307852003-11-08 01:05:38 +00001863<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +00001864
Chris Lattner48b383b02003-11-25 01:02:51 +00001865<p>As mentioned <a href="#functionstructure">previously</a>, every
1866basic block in a program ends with a "Terminator" instruction, which
1867indicates which block should be executed after the current block is
1868finished. These terminator instructions typically yield a '<tt>void</tt>'
1869value: they produce control flow, not values (the one exception being
1870the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +00001871<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +00001872 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1873instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +00001874the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1875 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1876 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +00001877
Misha Brukman76307852003-11-08 01:05:38 +00001878</div>
Chris Lattner74d3f822004-12-09 17:30:23 +00001879
Chris Lattner2f7c9632001-06-06 20:29:01 +00001880<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001881<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1882Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001883<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00001884<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001885<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 +00001886 ret void <i>; Return from void function</i>
Devang Pateld6cff512008-03-10 20:49:15 +00001887 ret &lt;type&gt; &lt;value&gt;, &lt;type&gt; &lt;value&gt; <i>; Return two values from a non-void function </i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001888</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001889
Chris Lattner2f7c9632001-06-06 20:29:01 +00001890<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001891
Chris Lattner48b383b02003-11-25 01:02:51 +00001892<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell4a3327e2005-05-13 22:25:59 +00001893value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +00001894<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattnerda508ac2008-04-23 04:59:35 +00001895returns value(s) and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +00001896control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001897
Chris Lattner2f7c9632001-06-06 20:29:01 +00001898<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001899
1900<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
1901The type of each return value must be a '<a href="#t_firstclass">first
1902class</a>' type. Note that a function is not <a href="#wellformed">well
1903formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
1904function that returns values that do not match the return type of the
1905function.</p>
1906
Chris Lattner2f7c9632001-06-06 20:29:01 +00001907<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001908
Chris Lattner48b383b02003-11-25 01:02:51 +00001909<p>When the '<tt>ret</tt>' instruction is executed, control flow
1910returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +00001911 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +00001912the instruction after the call. If the caller was an "<a
1913 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +00001914at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +00001915returns a value, that value shall set the call or invoke instruction's
Devang Pateld6cff512008-03-10 20:49:15 +00001916return value. If the instruction returns multiple values then these
Devang Pateld0f47642008-03-11 05:51:59 +00001917values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
1918</a>' instruction.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001919
Chris Lattner2f7c9632001-06-06 20:29:01 +00001920<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +00001921
1922<pre>
1923 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +00001924 ret void <i>; Return from a void function</i>
Devang Pateld6cff512008-03-10 20:49:15 +00001925 ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001926</pre>
Misha Brukman76307852003-11-08 01:05:38 +00001927</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001928<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00001929<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00001930<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00001931<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +00001932<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 +00001933</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001934<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001935<p>The '<tt>br</tt>' instruction is used to cause control flow to
1936transfer to a different basic block in the current function. There are
1937two forms of this instruction, corresponding to a conditional branch
1938and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001939<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00001940<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +00001941single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +00001942unconditional form of the '<tt>br</tt>' instruction takes a single
1943'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001944<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +00001945<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +00001946argument is evaluated. If the value is <tt>true</tt>, control flows
1947to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1948control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001949<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +00001950<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 +00001951 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 +00001952</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001953<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001954<div class="doc_subsubsection">
1955 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1956</div>
1957
Misha Brukman76307852003-11-08 01:05:38 +00001958<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00001959<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001960
1961<pre>
1962 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1963</pre>
1964
Chris Lattner2f7c9632001-06-06 20:29:01 +00001965<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001966
1967<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1968several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +00001969instruction, allowing a branch to occur to one of many possible
1970destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001971
1972
Chris Lattner2f7c9632001-06-06 20:29:01 +00001973<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001974
1975<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1976comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1977an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1978table is not allowed to contain duplicate constant entries.</p>
1979
Chris Lattner2f7c9632001-06-06 20:29:01 +00001980<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001981
Chris Lattner48b383b02003-11-25 01:02:51 +00001982<p>The <tt>switch</tt> instruction specifies a table of values and
1983destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +00001984table is searched for the given value. If the value is found, control flow is
1985transfered to the corresponding destination; otherwise, control flow is
1986transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00001987
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001988<h5>Implementation:</h5>
1989
1990<p>Depending on properties of the target machine and the particular
1991<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +00001992ways. For example, it could be generated as a series of chained conditional
1993branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +00001994
1995<h5>Example:</h5>
1996
1997<pre>
1998 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +00001999 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002000 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +00002001
2002 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002003 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +00002004
2005 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002006 switch i32 %val, label %otherwise [ i32 0, label %onzero
2007 i32 1, label %onone
2008 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +00002009</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002010</div>
Chris Lattner0132aff2005-05-06 22:57:40 +00002011
Chris Lattner2f7c9632001-06-06 20:29:01 +00002012<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +00002013<div class="doc_subsubsection">
2014 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2015</div>
2016
Misha Brukman76307852003-11-08 01:05:38 +00002017<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +00002018
Chris Lattner2f7c9632001-06-06 20:29:01 +00002019<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +00002020
2021<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +00002022 &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 +00002023 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +00002024</pre>
2025
Chris Lattnera8292f32002-05-06 22:08:29 +00002026<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +00002027
2028<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2029function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +00002030'<tt>normal</tt>' label or the
2031'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +00002032"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2033"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +00002034href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Pateld6cff512008-03-10 20:49:15 +00002035continued at the dynamically nearest "exception" label. If the callee function
Devang Pateld0f47642008-03-11 05:51:59 +00002036returns multiple values then individual return values are only accessible through
2037a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +00002038
Chris Lattner2f7c9632001-06-06 20:29:01 +00002039<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +00002040
Misha Brukman76307852003-11-08 01:05:38 +00002041<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +00002042
Chris Lattner2f7c9632001-06-06 20:29:01 +00002043<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +00002044 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +00002045 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +00002046 convention</a> the call should use. If none is specified, the call defaults
2047 to using C calling conventions.
2048 </li>
2049 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2050 function value being invoked. In most cases, this is a direct function
2051 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2052 an arbitrary pointer to function value.
2053 </li>
2054
2055 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2056 function to be invoked. </li>
2057
2058 <li>'<tt>function args</tt>': argument list whose types match the function
2059 signature argument types. If the function signature indicates the function
2060 accepts a variable number of arguments, the extra arguments can be
2061 specified. </li>
2062
2063 <li>'<tt>normal label</tt>': the label reached when the called function
2064 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2065
2066 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2067 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2068
Chris Lattner2f7c9632001-06-06 20:29:01 +00002069</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +00002070
Chris Lattner2f7c9632001-06-06 20:29:01 +00002071<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +00002072
Misha Brukman76307852003-11-08 01:05:38 +00002073<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +00002074href="#i_call">call</a></tt>' instruction in most regards. The primary
2075difference is that it establishes an association with a label, which is used by
2076the runtime library to unwind the stack.</p>
2077
2078<p>This instruction is used in languages with destructors to ensure that proper
2079cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2080exception. Additionally, this is important for implementation of
2081'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2082
Chris Lattner2f7c9632001-06-06 20:29:01 +00002083<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +00002084<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +00002085 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +00002086 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +00002087 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +00002088 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002089</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002090</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002091
2092
Chris Lattner5ed60612003-09-03 00:41:47 +00002093<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002094
Chris Lattner48b383b02003-11-25 01:02:51 +00002095<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2096Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002097
Misha Brukman76307852003-11-08 01:05:38 +00002098<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002099
Chris Lattner5ed60612003-09-03 00:41:47 +00002100<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002101<pre>
2102 unwind
2103</pre>
2104
Chris Lattner5ed60612003-09-03 00:41:47 +00002105<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002106
2107<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2108at the first callee in the dynamic call stack which used an <a
2109href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2110primarily used to implement exception handling.</p>
2111
Chris Lattner5ed60612003-09-03 00:41:47 +00002112<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002113
Chris Lattnerfe8519c2008-04-19 21:01:16 +00002114<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002115immediately halt. The dynamic call stack is then searched for the first <a
2116href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2117execution continues at the "exceptional" destination block specified by the
2118<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2119dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +00002120</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +00002121
2122<!-- _______________________________________________________________________ -->
2123
2124<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2125Instruction</a> </div>
2126
2127<div class="doc_text">
2128
2129<h5>Syntax:</h5>
2130<pre>
2131 unreachable
2132</pre>
2133
2134<h5>Overview:</h5>
2135
2136<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2137instruction is used to inform the optimizer that a particular portion of the
2138code is not reachable. This can be used to indicate that the code after a
2139no-return function cannot be reached, and other facts.</p>
2140
2141<h5>Semantics:</h5>
2142
2143<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2144</div>
2145
2146
2147
Chris Lattner2f7c9632001-06-06 20:29:01 +00002148<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +00002149<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00002150<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +00002151<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +00002152program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +00002153produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +00002154multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner81f92972008-04-01 18:47:32 +00002155The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +00002156<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +00002157</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002158<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002159<div class="doc_subsubsection">
2160 <a name="i_add">'<tt>add</tt>' Instruction</a>
2161</div>
2162
Misha Brukman76307852003-11-08 01:05:38 +00002163<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002164
Chris Lattner2f7c9632001-06-06 20:29:01 +00002165<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002166
2167<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002168 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002169</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002170
Chris Lattner2f7c9632001-06-06 20:29:01 +00002171<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002172
Misha Brukman76307852003-11-08 01:05:38 +00002173<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002174
Chris Lattner2f7c9632001-06-06 20:29:01 +00002175<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002176
2177<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2178 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2179 <a href="#t_vector">vector</a> values. Both arguments must have identical
2180 types.</p>
2181
Chris Lattner2f7c9632001-06-06 20:29:01 +00002182<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002183
Misha Brukman76307852003-11-08 01:05:38 +00002184<p>The value produced is the integer or floating point sum of the two
2185operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002186
Chris Lattner2f2427e2008-01-28 00:36:27 +00002187<p>If an integer sum has unsigned overflow, the result returned is the
2188mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2189the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002190
Chris Lattner2f2427e2008-01-28 00:36:27 +00002191<p>Because LLVM integers use a two's complement representation, this
2192instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002193
Chris Lattner2f7c9632001-06-06 20:29:01 +00002194<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002195
2196<pre>
2197 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002198</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002199</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002200<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002201<div class="doc_subsubsection">
2202 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2203</div>
2204
Misha Brukman76307852003-11-08 01:05:38 +00002205<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002206
Chris Lattner2f7c9632001-06-06 20:29:01 +00002207<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002208
2209<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002210 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002211</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002212
Chris Lattner2f7c9632001-06-06 20:29:01 +00002213<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002214
Misha Brukman76307852003-11-08 01:05:38 +00002215<p>The '<tt>sub</tt>' instruction returns the difference of its two
2216operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002217
2218<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2219'<tt>neg</tt>' instruction present in most other intermediate
2220representations.</p>
2221
Chris Lattner2f7c9632001-06-06 20:29:01 +00002222<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002223
2224<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2225 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2226 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2227 types.</p>
2228
Chris Lattner2f7c9632001-06-06 20:29:01 +00002229<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002230
Chris Lattner48b383b02003-11-25 01:02:51 +00002231<p>The value produced is the integer or floating point difference of
2232the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002233
Chris Lattner2f2427e2008-01-28 00:36:27 +00002234<p>If an integer difference has unsigned overflow, the result returned is the
2235mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2236the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002237
Chris Lattner2f2427e2008-01-28 00:36:27 +00002238<p>Because LLVM integers use a two's complement representation, this
2239instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002240
Chris Lattner2f7c9632001-06-06 20:29:01 +00002241<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +00002242<pre>
2243 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002244 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002245</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002246</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002247
Chris Lattner2f7c9632001-06-06 20:29:01 +00002248<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002249<div class="doc_subsubsection">
2250 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2251</div>
2252
Misha Brukman76307852003-11-08 01:05:38 +00002253<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002254
Chris Lattner2f7c9632001-06-06 20:29:01 +00002255<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002256<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002257</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002258<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00002259<p>The '<tt>mul</tt>' instruction returns the product of its two
2260operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002261
Chris Lattner2f7c9632001-06-06 20:29:01 +00002262<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002263
2264<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2265href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2266or <a href="#t_vector">vector</a> values. Both arguments must have identical
2267types.</p>
2268
Chris Lattner2f7c9632001-06-06 20:29:01 +00002269<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002270
Chris Lattner48b383b02003-11-25 01:02:51 +00002271<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +00002272two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002273
Chris Lattner2f2427e2008-01-28 00:36:27 +00002274<p>If the result of an integer multiplication has unsigned overflow,
2275the result returned is the mathematical result modulo
22762<sup>n</sup>, where n is the bit width of the result.</p>
2277<p>Because LLVM integers use a two's complement representation, and the
2278result is the same width as the operands, this instruction returns the
2279correct result for both signed and unsigned integers. If a full product
2280(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2281should be sign-extended or zero-extended as appropriate to the
2282width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002283<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002284<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002285</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002286</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002287
Chris Lattner2f7c9632001-06-06 20:29:01 +00002288<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002289<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2290</a></div>
2291<div class="doc_text">
2292<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002293<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002294</pre>
2295<h5>Overview:</h5>
2296<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2297operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002298
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002299<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002300
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002301<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002302<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2303values. Both arguments must have identical types.</p>
2304
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002305<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002306
Chris Lattner2f2427e2008-01-28 00:36:27 +00002307<p>The value produced is the unsigned integer quotient of the two operands.</p>
2308<p>Note that unsigned integer division and signed integer division are distinct
2309operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2310<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002311<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002312<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002313</pre>
2314</div>
2315<!-- _______________________________________________________________________ -->
2316<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2317</a> </div>
2318<div class="doc_text">
2319<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002320<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002321 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002322</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002323
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002324<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002325
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002326<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2327operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002328
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002329<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002330
2331<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2332<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2333values. Both arguments must have identical types.</p>
2334
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002335<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +00002336<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +00002337<p>Note that signed integer division and unsigned integer division are distinct
2338operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2339<p>Division by zero leads to undefined behavior. Overflow also leads to
2340undefined behavior; this is a rare case, but can occur, for example,
2341by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002342<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002343<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002344</pre>
2345</div>
2346<!-- _______________________________________________________________________ -->
2347<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +00002348Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00002349<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00002350<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002351<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002352 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +00002353</pre>
2354<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002355
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002356<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +00002357operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002358
Chris Lattner48b383b02003-11-25 01:02:51 +00002359<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002360
Jeff Cohen5819f182007-04-22 01:17:39 +00002361<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002362<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2363of floating point values. Both arguments must have identical types.</p>
2364
Chris Lattner48b383b02003-11-25 01:02:51 +00002365<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002366
Reid Spencer7e80b0b2006-10-26 06:15:43 +00002367<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002368
Chris Lattner48b383b02003-11-25 01:02:51 +00002369<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002370
2371<pre>
2372 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +00002373</pre>
2374</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002375
Chris Lattner48b383b02003-11-25 01:02:51 +00002376<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +00002377<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2378</div>
2379<div class="doc_text">
2380<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002381<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +00002382</pre>
2383<h5>Overview:</h5>
2384<p>The '<tt>urem</tt>' instruction returns the remainder from the
2385unsigned division of its two arguments.</p>
2386<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002387<p>The two arguments to the '<tt>urem</tt>' instruction must be
2388<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2389values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +00002390<h5>Semantics:</h5>
2391<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +00002392This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +00002393<p>Note that unsigned integer remainder and signed integer remainder are
2394distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2395<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +00002396<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002397<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +00002398</pre>
2399
2400</div>
2401<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002402<div class="doc_subsubsection">
2403 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2404</div>
2405
Chris Lattner48b383b02003-11-25 01:02:51 +00002406<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002407
Chris Lattner48b383b02003-11-25 01:02:51 +00002408<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002409
2410<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002411 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +00002412</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002413
Chris Lattner48b383b02003-11-25 01:02:51 +00002414<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002415
Reid Spencer7eb55b32006-11-02 01:53:59 +00002416<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +00002417signed division of its two operands. This instruction can also take
2418<a href="#t_vector">vector</a> versions of the values in which case
2419the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +00002420
Chris Lattner48b383b02003-11-25 01:02:51 +00002421<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002422
Reid Spencer7eb55b32006-11-02 01:53:59 +00002423<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002424<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2425values. Both arguments must have identical types.</p>
2426
Chris Lattner48b383b02003-11-25 01:02:51 +00002427<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002428
Reid Spencer7eb55b32006-11-02 01:53:59 +00002429<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +00002430has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2431operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +00002432a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +00002433 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +00002434Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +00002435please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +00002436Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +00002437<p>Note that signed integer remainder and unsigned integer remainder are
2438distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2439<p>Taking the remainder of a division by zero leads to undefined behavior.
2440Overflow also leads to undefined behavior; this is a rare case, but can occur,
2441for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2442(The remainder doesn't actually overflow, but this rule lets srem be
2443implemented using instructions that return both the result of the division
2444and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00002445<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002446<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +00002447</pre>
2448
2449</div>
2450<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002451<div class="doc_subsubsection">
2452 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2453
Reid Spencer7eb55b32006-11-02 01:53:59 +00002454<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002455
Reid Spencer7eb55b32006-11-02 01:53:59 +00002456<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002457<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +00002458</pre>
2459<h5>Overview:</h5>
2460<p>The '<tt>frem</tt>' instruction returns the remainder from the
2461division of its two operands.</p>
2462<h5>Arguments:</h5>
2463<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002464<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2465of floating point values. Both arguments must have identical types.</p>
2466
Reid Spencer7eb55b32006-11-02 01:53:59 +00002467<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002468
Chris Lattner1429e6f2008-04-01 18:45:27 +00002469<p>This instruction returns the <i>remainder</i> of a division.
2470The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002471
Reid Spencer7eb55b32006-11-02 01:53:59 +00002472<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002473
2474<pre>
2475 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +00002476</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002477</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +00002478
Reid Spencer2ab01932007-02-02 13:57:07 +00002479<!-- ======================================================================= -->
2480<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2481Operations</a> </div>
2482<div class="doc_text">
2483<p>Bitwise binary operators are used to do various forms of
2484bit-twiddling in a program. They are generally very efficient
2485instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +00002486instructions. They require two operands of the same type, execute an operation on them,
2487and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer2ab01932007-02-02 13:57:07 +00002488</div>
2489
Reid Spencer04e259b2007-01-31 21:39:12 +00002490<!-- _______________________________________________________________________ -->
2491<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2492Instruction</a> </div>
2493<div class="doc_text">
2494<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002495<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +00002496</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002497
Reid Spencer04e259b2007-01-31 21:39:12 +00002498<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002499
Reid Spencer04e259b2007-01-31 21:39:12 +00002500<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2501the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002502
Reid Spencer04e259b2007-01-31 21:39:12 +00002503<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002504
Reid Spencer04e259b2007-01-31 21:39:12 +00002505<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +00002506 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +00002507type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002508
Reid Spencer04e259b2007-01-31 21:39:12 +00002509<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002510
Gabor Greif0f75ad02008-08-07 21:46:00 +00002511<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2512where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2513equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002514
Reid Spencer04e259b2007-01-31 21:39:12 +00002515<h5>Example:</h5><pre>
2516 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2517 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2518 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002519 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +00002520</pre>
2521</div>
2522<!-- _______________________________________________________________________ -->
2523<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2524Instruction</a> </div>
2525<div class="doc_text">
2526<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002527<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +00002528</pre>
2529
2530<h5>Overview:</h5>
2531<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +00002532operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +00002533
2534<h5>Arguments:</h5>
2535<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +00002536<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +00002537type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +00002538
2539<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002540
Reid Spencer04e259b2007-01-31 21:39:12 +00002541<p>This instruction always performs a logical shift right operation. The most
2542significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +00002543shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2544the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +00002545
2546<h5>Example:</h5>
2547<pre>
2548 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2549 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2550 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2551 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002552 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +00002553</pre>
2554</div>
2555
Reid Spencer2ab01932007-02-02 13:57:07 +00002556<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +00002557<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2558Instruction</a> </div>
2559<div class="doc_text">
2560
2561<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002562<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +00002563</pre>
2564
2565<h5>Overview:</h5>
2566<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +00002567operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +00002568
2569<h5>Arguments:</h5>
2570<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +00002571<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +00002572type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +00002573
2574<h5>Semantics:</h5>
2575<p>This instruction always performs an arithmetic shift right operation,
2576The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +00002577of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2578larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattnerf0e50112007-10-03 21:01:14 +00002579</p>
Reid Spencer04e259b2007-01-31 21:39:12 +00002580
2581<h5>Example:</h5>
2582<pre>
2583 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2584 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2585 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2586 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +00002587 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +00002588</pre>
2589</div>
2590
Chris Lattner2f7c9632001-06-06 20:29:01 +00002591<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00002592<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2593Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002594
Misha Brukman76307852003-11-08 01:05:38 +00002595<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002596
Chris Lattner2f7c9632001-06-06 20:29:01 +00002597<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002598
2599<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002600 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002601</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002602
Chris Lattner2f7c9632001-06-06 20:29:01 +00002603<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002604
Chris Lattner48b383b02003-11-25 01:02:51 +00002605<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2606its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002607
Chris Lattner2f7c9632001-06-06 20:29:01 +00002608<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002609
2610<p>The two arguments to the '<tt>and</tt>' instruction must be
2611<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2612values. Both arguments must have identical types.</p>
2613
Chris Lattner2f7c9632001-06-06 20:29:01 +00002614<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +00002615<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00002616<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +00002617<div>
Misha Brukman76307852003-11-08 01:05:38 +00002618<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +00002619 <tbody>
2620 <tr>
2621 <td>In0</td>
2622 <td>In1</td>
2623 <td>Out</td>
2624 </tr>
2625 <tr>
2626 <td>0</td>
2627 <td>0</td>
2628 <td>0</td>
2629 </tr>
2630 <tr>
2631 <td>0</td>
2632 <td>1</td>
2633 <td>0</td>
2634 </tr>
2635 <tr>
2636 <td>1</td>
2637 <td>0</td>
2638 <td>0</td>
2639 </tr>
2640 <tr>
2641 <td>1</td>
2642 <td>1</td>
2643 <td>1</td>
2644 </tr>
2645 </tbody>
2646</table>
Misha Brukmanc501f552004-03-01 17:47:27 +00002647</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002648<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002649<pre>
2650 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002651 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2652 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002653</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002654</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002655<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00002656<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00002657<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00002658<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002659<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002660</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +00002661<h5>Overview:</h5>
2662<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2663or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002664<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002665
2666<p>The two arguments to the '<tt>or</tt>' instruction must be
2667<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2668values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002669<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +00002670<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00002671<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +00002672<div>
Chris Lattner48b383b02003-11-25 01:02:51 +00002673<table border="1" cellspacing="0" cellpadding="4">
2674 <tbody>
2675 <tr>
2676 <td>In0</td>
2677 <td>In1</td>
2678 <td>Out</td>
2679 </tr>
2680 <tr>
2681 <td>0</td>
2682 <td>0</td>
2683 <td>0</td>
2684 </tr>
2685 <tr>
2686 <td>0</td>
2687 <td>1</td>
2688 <td>1</td>
2689 </tr>
2690 <tr>
2691 <td>1</td>
2692 <td>0</td>
2693 <td>1</td>
2694 </tr>
2695 <tr>
2696 <td>1</td>
2697 <td>1</td>
2698 <td>1</td>
2699 </tr>
2700 </tbody>
2701</table>
Misha Brukmanc501f552004-03-01 17:47:27 +00002702</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002703<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002704<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2705 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2706 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002707</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002708</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002709<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00002710<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2711Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00002712<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +00002713<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00002714<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002715</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002716<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00002717<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2718or of its two operands. The <tt>xor</tt> is used to implement the
2719"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002720<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002721<p>The two arguments to the '<tt>xor</tt>' instruction must be
2722<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2723values. Both arguments must have identical types.</p>
2724
Chris Lattner2f7c9632001-06-06 20:29:01 +00002725<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00002726
Misha Brukman76307852003-11-08 01:05:38 +00002727<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00002728<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +00002729<div>
Chris Lattner48b383b02003-11-25 01:02:51 +00002730<table border="1" cellspacing="0" cellpadding="4">
2731 <tbody>
2732 <tr>
2733 <td>In0</td>
2734 <td>In1</td>
2735 <td>Out</td>
2736 </tr>
2737 <tr>
2738 <td>0</td>
2739 <td>0</td>
2740 <td>0</td>
2741 </tr>
2742 <tr>
2743 <td>0</td>
2744 <td>1</td>
2745 <td>1</td>
2746 </tr>
2747 <tr>
2748 <td>1</td>
2749 <td>0</td>
2750 <td>1</td>
2751 </tr>
2752 <tr>
2753 <td>1</td>
2754 <td>1</td>
2755 <td>0</td>
2756 </tr>
2757 </tbody>
2758</table>
Misha Brukmanc501f552004-03-01 17:47:27 +00002759</div>
Chris Lattner48b383b02003-11-25 01:02:51 +00002760<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002761<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002762<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2763 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2764 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2765 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00002766</pre>
Misha Brukman76307852003-11-08 01:05:38 +00002767</div>
Chris Lattner54611b42005-11-06 08:02:57 +00002768
Chris Lattner2f7c9632001-06-06 20:29:01 +00002769<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +00002770<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +00002771 <a name="vectorops">Vector Operations</a>
2772</div>
2773
2774<div class="doc_text">
2775
2776<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +00002777target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +00002778vector-specific operations needed to process vectors effectively. While LLVM
2779does directly support these vector operations, many sophisticated algorithms
2780will want to use target-specific intrinsics to take full advantage of a specific
2781target.</p>
2782
2783</div>
2784
2785<!-- _______________________________________________________________________ -->
2786<div class="doc_subsubsection">
2787 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2788</div>
2789
2790<div class="doc_text">
2791
2792<h5>Syntax:</h5>
2793
2794<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002795 &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 +00002796</pre>
2797
2798<h5>Overview:</h5>
2799
2800<p>
2801The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +00002802element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +00002803</p>
2804
2805
2806<h5>Arguments:</h5>
2807
2808<p>
2809The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +00002810value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +00002811an index indicating the position from which to extract the element.
2812The index may be a variable.</p>
2813
2814<h5>Semantics:</h5>
2815
2816<p>
2817The result is a scalar of the same type as the element type of
2818<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2819<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2820results are undefined.
2821</p>
2822
2823<h5>Example:</h5>
2824
2825<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002826 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +00002827</pre>
2828</div>
2829
2830
2831<!-- _______________________________________________________________________ -->
2832<div class="doc_subsubsection">
2833 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2834</div>
2835
2836<div class="doc_text">
2837
2838<h5>Syntax:</h5>
2839
2840<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +00002841 &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 +00002842</pre>
2843
2844<h5>Overview:</h5>
2845
2846<p>
2847The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +00002848element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +00002849</p>
2850
2851
2852<h5>Arguments:</h5>
2853
2854<p>
2855The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +00002856value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +00002857scalar value whose type must equal the element type of the first
2858operand. The third operand is an index indicating the position at
2859which to insert the value. The index may be a variable.</p>
2860
2861<h5>Semantics:</h5>
2862
2863<p>
Reid Spencer404a3252007-02-15 03:07:05 +00002864The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +00002865element values are those of <tt>val</tt> except at position
2866<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2867exceeds the length of <tt>val</tt>, the results are undefined.
2868</p>
2869
2870<h5>Example:</h5>
2871
2872<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002873 %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 +00002874</pre>
2875</div>
2876
2877<!-- _______________________________________________________________________ -->
2878<div class="doc_subsubsection">
2879 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2880</div>
2881
2882<div class="doc_text">
2883
2884<h5>Syntax:</h5>
2885
2886<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002887 &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 +00002888</pre>
2889
2890<h5>Overview:</h5>
2891
2892<p>
2893The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2894from two input vectors, returning a vector of the same type.
2895</p>
2896
2897<h5>Arguments:</h5>
2898
2899<p>
2900The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2901with types that match each other and types that match the result of the
2902instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002903of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +00002904</p>
2905
2906<p>
2907The shuffle mask operand is required to be a constant vector with either
2908constant integer or undef values.
2909</p>
2910
2911<h5>Semantics:</h5>
2912
2913<p>
2914The elements of the two input vectors are numbered from left to right across
2915both of the vectors. The shuffle mask operand specifies, for each element of
2916the result vector, which element of the two input registers the result element
2917gets. The element selector may be undef (meaning "don't care") and the second
2918operand may be undef if performing a shuffle from only one vector.
2919</p>
2920
2921<h5>Example:</h5>
2922
2923<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00002924 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +00002925 &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 +00002926 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2927 &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 +00002928</pre>
2929</div>
2930
Tanya Lattnerb138bbe2006-04-14 19:24:33 +00002931
Chris Lattnerce83bff2006-04-08 23:07:04 +00002932<!-- ======================================================================= -->
2933<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +00002934 <a name="aggregateops">Aggregate Operations</a>
2935</div>
2936
2937<div class="doc_text">
2938
2939<p>LLVM supports several instructions for working with aggregate values.
2940</p>
2941
2942</div>
2943
2944<!-- _______________________________________________________________________ -->
2945<div class="doc_subsubsection">
2946 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
2947</div>
2948
2949<div class="doc_text">
2950
2951<h5>Syntax:</h5>
2952
2953<pre>
2954 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
2955</pre>
2956
2957<h5>Overview:</h5>
2958
2959<p>
Dan Gohman35a835c2008-05-13 18:16:06 +00002960The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
2961or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +00002962</p>
2963
2964
2965<h5>Arguments:</h5>
2966
2967<p>
2968The first operand of an '<tt>extractvalue</tt>' instruction is a
2969value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +00002970type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +00002971in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +00002972'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2973</p>
2974
2975<h5>Semantics:</h5>
2976
2977<p>
2978The result is the value at the position in the aggregate specified by
2979the index operands.
2980</p>
2981
2982<h5>Example:</h5>
2983
2984<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +00002985 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +00002986</pre>
2987</div>
2988
2989
2990<!-- _______________________________________________________________________ -->
2991<div class="doc_subsubsection">
2992 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
2993</div>
2994
2995<div class="doc_text">
2996
2997<h5>Syntax:</h5>
2998
2999<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +00003000 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +00003001</pre>
3002
3003<h5>Overview:</h5>
3004
3005<p>
3006The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +00003007into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +00003008</p>
3009
3010
3011<h5>Arguments:</h5>
3012
3013<p>
3014The first operand of an '<tt>insertvalue</tt>' instruction is a
3015value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3016The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +00003017The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +00003018indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +00003019indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +00003020'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3021The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +00003022by the indices.
Dan Gohmanb9d66602008-05-12 23:51:09 +00003023
3024<h5>Semantics:</h5>
3025
3026<p>
3027The result is an aggregate of the same type as <tt>val</tt>. Its
3028value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +00003029specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +00003030</p>
3031
3032<h5>Example:</h5>
3033
3034<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +00003035 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +00003036</pre>
3037</div>
3038
3039
3040<!-- ======================================================================= -->
3041<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +00003042 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +00003043</div>
3044
Misha Brukman76307852003-11-08 01:05:38 +00003045<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +00003046
Chris Lattner48b383b02003-11-25 01:02:51 +00003047<p>A key design point of an SSA-based representation is how it
3048represents memory. In LLVM, no memory locations are in SSA form, which
3049makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +00003050allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003051
Misha Brukman76307852003-11-08 01:05:38 +00003052</div>
Chris Lattner54611b42005-11-06 08:02:57 +00003053
Chris Lattner2f7c9632001-06-06 20:29:01 +00003054<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +00003055<div class="doc_subsubsection">
3056 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3057</div>
3058
Misha Brukman76307852003-11-08 01:05:38 +00003059<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +00003060
Chris Lattner2f7c9632001-06-06 20:29:01 +00003061<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003062
3063<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003064 &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 +00003065</pre>
Chris Lattner54611b42005-11-06 08:02:57 +00003066
Chris Lattner2f7c9632001-06-06 20:29:01 +00003067<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003068
Chris Lattner48b383b02003-11-25 01:02:51 +00003069<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +00003070heap and returns a pointer to it. The object is always allocated in the generic
3071address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003072
Chris Lattner2f7c9632001-06-06 20:29:01 +00003073<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003074
3075<p>The '<tt>malloc</tt>' instruction allocates
3076<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +00003077bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +00003078appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +00003079number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +00003080If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +00003081be aligned to at least that boundary. If not specified, or if zero, the target can
3082choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003083
Misha Brukman76307852003-11-08 01:05:38 +00003084<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003085
Chris Lattner2f7c9632001-06-06 20:29:01 +00003086<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003087
Chris Lattner48b383b02003-11-25 01:02:51 +00003088<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattnerfe8519c2008-04-19 21:01:16 +00003089a pointer is returned. The result of a zero byte allocattion is undefined. The
3090result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +00003091
Chris Lattner54611b42005-11-06 08:02:57 +00003092<h5>Example:</h5>
3093
3094<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003095 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +00003096
Bill Wendling2d8b9a82007-05-29 09:42:13 +00003097 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3098 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3099 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3100 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3101 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00003102</pre>
Misha Brukman76307852003-11-08 01:05:38 +00003103</div>
Chris Lattner54611b42005-11-06 08:02:57 +00003104
Chris Lattner2f7c9632001-06-06 20:29:01 +00003105<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +00003106<div class="doc_subsubsection">
3107 <a name="i_free">'<tt>free</tt>' Instruction</a>
3108</div>
3109
Misha Brukman76307852003-11-08 01:05:38 +00003110<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +00003111
Chris Lattner2f7c9632001-06-06 20:29:01 +00003112<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003113
3114<pre>
3115 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00003116</pre>
Chris Lattner54611b42005-11-06 08:02:57 +00003117
Chris Lattner2f7c9632001-06-06 20:29:01 +00003118<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003119
Chris Lattner48b383b02003-11-25 01:02:51 +00003120<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +00003121memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003122
Chris Lattner2f7c9632001-06-06 20:29:01 +00003123<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003124
Chris Lattner48b383b02003-11-25 01:02:51 +00003125<p>'<tt>value</tt>' shall be a pointer value that points to a value
3126that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3127instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003128
Chris Lattner2f7c9632001-06-06 20:29:01 +00003129<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003130
John Criswelldfe6a862004-12-10 15:51:16 +00003131<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +00003132after this instruction executes. If the pointer is null, the operation
3133is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003134
Chris Lattner2f7c9632001-06-06 20:29:01 +00003135<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003136
3137<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003138 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3139 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +00003140</pre>
Misha Brukman76307852003-11-08 01:05:38 +00003141</div>
Chris Lattner54611b42005-11-06 08:02:57 +00003142
Chris Lattner2f7c9632001-06-06 20:29:01 +00003143<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +00003144<div class="doc_subsubsection">
3145 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3146</div>
3147
Misha Brukman76307852003-11-08 01:05:38 +00003148<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +00003149
Chris Lattner2f7c9632001-06-06 20:29:01 +00003150<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003151
3152<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003153 &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 +00003154</pre>
Chris Lattner54611b42005-11-06 08:02:57 +00003155
Chris Lattner2f7c9632001-06-06 20:29:01 +00003156<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003157
Jeff Cohen5819f182007-04-22 01:17:39 +00003158<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3159currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +00003160returns to its caller. The object is always allocated in the generic address
3161space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003162
Chris Lattner2f7c9632001-06-06 20:29:01 +00003163<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003164
John Criswelldfe6a862004-12-10 15:51:16 +00003165<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +00003166bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +00003167appropriate type to the program. If "NumElements" is specified, it is the
3168number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +00003169If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +00003170to be aligned to at least that boundary. If not specified, or if zero, the target
3171can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003172
Misha Brukman76307852003-11-08 01:05:38 +00003173<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003174
Chris Lattner2f7c9632001-06-06 20:29:01 +00003175<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003176
Chris Lattnerfe8519c2008-04-19 21:01:16 +00003177<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3178there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +00003179memory is automatically released when the function returns. The '<tt>alloca</tt>'
3180instruction is commonly used to represent automatic variables that must
3181have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +00003182 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner1f17cce2008-04-02 00:38:26 +00003183instructions), the memory is reclaimed. Allocating zero bytes
3184is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +00003185
Chris Lattner2f7c9632001-06-06 20:29:01 +00003186<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +00003187
3188<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003189 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +00003190 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3191 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003192 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +00003193</pre>
Misha Brukman76307852003-11-08 01:05:38 +00003194</div>
Chris Lattner54611b42005-11-06 08:02:57 +00003195
Chris Lattner2f7c9632001-06-06 20:29:01 +00003196<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00003197<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3198Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +00003199<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +00003200<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +00003201<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 +00003202<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +00003203<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +00003204<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00003205<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +00003206address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +00003207 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +00003208marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +00003209the number or order of execution of this <tt>load</tt> with other
3210volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3211instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +00003212<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +00003213The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +00003214(that is, the alignment of the memory address). A value of 0 or an
3215omitted "align" argument means that the operation has the preferential
3216alignment for the target. It is the responsibility of the code emitter
3217to ensure that the alignment information is correct. Overestimating
3218the alignment results in an undefined behavior. Underestimating the
3219alignment may produce less efficient code. An alignment of 1 is always
3220safe.
3221</p>
Chris Lattner095735d2002-05-06 03:03:22 +00003222<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +00003223<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +00003224<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003225<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +00003226 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003227 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3228 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +00003229</pre>
Misha Brukman76307852003-11-08 01:05:38 +00003230</div>
Chris Lattner095735d2002-05-06 03:03:22 +00003231<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +00003232<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3233Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +00003234<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +00003235<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +00003236<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3237 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 +00003238</pre>
Chris Lattner095735d2002-05-06 03:03:22 +00003239<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +00003240<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +00003241<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +00003242<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +00003243to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner1f17cce2008-04-02 00:38:26 +00003244operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3245of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +00003246operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +00003247optimizer is not allowed to modify the number or order of execution of
3248this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3249 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +00003250<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +00003251The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +00003252(that is, the alignment of the memory address). A value of 0 or an
3253omitted "align" argument means that the operation has the preferential
3254alignment for the target. It is the responsibility of the code emitter
3255to ensure that the alignment information is correct. Overestimating
3256the alignment results in an undefined behavior. Underestimating the
3257alignment may produce less efficient code. An alignment of 1 is always
3258safe.
3259</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00003260<h5>Semantics:</h5>
3261<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3262at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +00003263<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003264<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +00003265 store i32 3, i32* %ptr <i>; yields {void}</i>
3266 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +00003267</pre>
Reid Spencer443460a2006-11-09 21:15:49 +00003268</div>
3269
Chris Lattner095735d2002-05-06 03:03:22 +00003270<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +00003271<div class="doc_subsubsection">
3272 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3273</div>
3274
Misha Brukman76307852003-11-08 01:05:38 +00003275<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +00003276<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +00003277<pre>
3278 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
3279</pre>
3280
Chris Lattner590645f2002-04-14 06:13:44 +00003281<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +00003282
3283<p>
3284The '<tt>getelementptr</tt>' instruction is used to get the address of a
3285subelement of an aggregate data structure.</p>
3286
Chris Lattner590645f2002-04-14 06:13:44 +00003287<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +00003288
Reid Spencercee005c2006-12-04 21:29:24 +00003289<p>This instruction takes a list of integer operands that indicate what
Chris Lattner33fd7022004-04-05 01:30:49 +00003290elements of the aggregate object to index to. The actual types of the arguments
3291provided depend on the type of the first pointer argument. The
3292'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell88190562005-05-16 16:17:45 +00003293levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003294structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner851b7712008-04-24 05:59:56 +00003295into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
3296values will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +00003297
Chris Lattner48b383b02003-11-25 01:02:51 +00003298<p>For example, let's consider a C code fragment and how it gets
3299compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +00003300
Bill Wendling3716c5d2007-05-29 09:04:49 +00003301<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +00003302<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00003303struct RT {
3304 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +00003305 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +00003306 char C;
3307};
3308struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +00003309 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +00003310 double Y;
3311 struct RT Z;
3312};
Chris Lattner33fd7022004-04-05 01:30:49 +00003313
Chris Lattnera446f1b2007-05-29 15:43:56 +00003314int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +00003315 return &amp;s[1].Z.B[5][13];
3316}
Chris Lattner33fd7022004-04-05 01:30:49 +00003317</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00003318</div>
Chris Lattner33fd7022004-04-05 01:30:49 +00003319
Misha Brukman76307852003-11-08 01:05:38 +00003320<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +00003321
Bill Wendling3716c5d2007-05-29 09:04:49 +00003322<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +00003323<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00003324%RT = type { i8 , [10 x [20 x i32]], i8 }
3325%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +00003326
Bill Wendling3716c5d2007-05-29 09:04:49 +00003327define i32* %foo(%ST* %s) {
3328entry:
3329 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3330 ret i32* %reg
3331}
Chris Lattner33fd7022004-04-05 01:30:49 +00003332</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +00003333</div>
Chris Lattner33fd7022004-04-05 01:30:49 +00003334
Chris Lattner590645f2002-04-14 06:13:44 +00003335<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +00003336
3337<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell4a3327e2005-05-13 22:25:59 +00003338on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencercee005c2006-12-04 21:29:24 +00003339and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencerc0312692006-12-03 16:53:48 +00003340<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner1f17cce2008-04-02 00:38:26 +00003341to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
3342structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +00003343
Misha Brukman76307852003-11-08 01:05:38 +00003344<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003345type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +00003346}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003347the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3348i8 }</tt>' type, another structure. The third index indexes into the second
3349element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +00003350array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003351'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3352to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +00003353
Chris Lattner48b383b02003-11-25 01:02:51 +00003354<p>Note that it is perfectly legal to index partially through a
3355structure, returning a pointer to an inner element. Because of this,
3356the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +00003357
3358<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003359 define i32* %foo(%ST* %s) {
3360 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +00003361 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3362 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003363 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3364 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3365 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +00003366 }
Chris Lattnera8292f32002-05-06 22:08:29 +00003367</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +00003368
3369<p>Note that it is undefined to access an array out of bounds: array and
3370pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +00003371The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +00003372defined to be accessible as variable length arrays, which requires access
3373beyond the zero'th element.</p>
3374
Chris Lattner6ab66722006-08-15 00:45:58 +00003375<p>The getelementptr instruction is often confusing. For some more insight
3376into how it works, see <a href="GetElementPtr.html">the getelementptr
3377FAQ</a>.</p>
3378
Chris Lattner590645f2002-04-14 06:13:44 +00003379<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +00003380
Chris Lattner33fd7022004-04-05 01:30:49 +00003381<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003382 <i>; yields [12 x i8]*:aptr</i>
3383 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +00003384</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +00003385</div>
Reid Spencer443460a2006-11-09 21:15:49 +00003386
Chris Lattner2f7c9632001-06-06 20:29:01 +00003387<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +00003388<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +00003389</div>
Misha Brukman76307852003-11-08 01:05:38 +00003390<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +00003391<p>The instructions in this category are the conversion instructions (casting)
3392which all take a single operand and a type. They perform various bit conversions
3393on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +00003394</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003395
Chris Lattnera8292f32002-05-06 22:08:29 +00003396<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003397<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003398 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3399</div>
3400<div class="doc_text">
3401
3402<h5>Syntax:</h5>
3403<pre>
3404 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3405</pre>
3406
3407<h5>Overview:</h5>
3408<p>
3409The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3410</p>
3411
3412<h5>Arguments:</h5>
3413<p>
3414The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3415be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattnerc0f423a2007-01-15 01:54:13 +00003416and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +00003417type. The bit size of <tt>value</tt> must be larger than the bit size of
3418<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003419
3420<h5>Semantics:</h5>
3421<p>
3422The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +00003423and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3424larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3425It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003426
3427<h5>Example:</h5>
3428<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003429 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +00003430 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3431 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003432</pre>
3433</div>
3434
3435<!-- _______________________________________________________________________ -->
3436<div class="doc_subsubsection">
3437 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3438</div>
3439<div class="doc_text">
3440
3441<h5>Syntax:</h5>
3442<pre>
3443 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3444</pre>
3445
3446<h5>Overview:</h5>
3447<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3448<tt>ty2</tt>.</p>
3449
3450
3451<h5>Arguments:</h5>
3452<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +00003453<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3454also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +00003455<tt>value</tt> must be smaller than the bit size of the destination type,
3456<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003457
3458<h5>Semantics:</h5>
3459<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerc87f3df2007-05-24 19:13:27 +00003460bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003461
Reid Spencer07c9c682007-01-12 15:46:11 +00003462<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003463
3464<h5>Example:</h5>
3465<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003466 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +00003467 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003468</pre>
3469</div>
3470
3471<!-- _______________________________________________________________________ -->
3472<div class="doc_subsubsection">
3473 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3474</div>
3475<div class="doc_text">
3476
3477<h5>Syntax:</h5>
3478<pre>
3479 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3480</pre>
3481
3482<h5>Overview:</h5>
3483<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3484
3485<h5>Arguments:</h5>
3486<p>
3487The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +00003488<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3489also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +00003490<tt>value</tt> must be smaller than the bit size of the destination type,
3491<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003492
3493<h5>Semantics:</h5>
3494<p>
3495The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3496bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerc87f3df2007-05-24 19:13:27 +00003497the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003498
Reid Spencer36a15422007-01-12 03:35:51 +00003499<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003500
3501<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003502<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003503 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +00003504 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003505</pre>
3506</div>
3507
3508<!-- _______________________________________________________________________ -->
3509<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +00003510 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3511</div>
3512
3513<div class="doc_text">
3514
3515<h5>Syntax:</h5>
3516
3517<pre>
3518 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3519</pre>
3520
3521<h5>Overview:</h5>
3522<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3523<tt>ty2</tt>.</p>
3524
3525
3526<h5>Arguments:</h5>
3527<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3528 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3529cast it to. The size of <tt>value</tt> must be larger than the size of
3530<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3531<i>no-op cast</i>.</p>
3532
3533<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003534<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3535<a href="#t_floating">floating point</a> type to a smaller
3536<a href="#t_floating">floating point</a> type. If the value cannot fit within
3537the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +00003538
3539<h5>Example:</h5>
3540<pre>
3541 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3542 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3543</pre>
3544</div>
3545
3546<!-- _______________________________________________________________________ -->
3547<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003548 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3549</div>
3550<div class="doc_text">
3551
3552<h5>Syntax:</h5>
3553<pre>
3554 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3555</pre>
3556
3557<h5>Overview:</h5>
3558<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3559floating point value.</p>
3560
3561<h5>Arguments:</h5>
3562<p>The '<tt>fpext</tt>' instruction takes a
3563<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +00003564and a <a href="#t_floating">floating point</a> type to cast it to. The source
3565type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003566
3567<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003568<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +00003569<a href="#t_floating">floating point</a> type to a larger
3570<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +00003571used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +00003572<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003573
3574<h5>Example:</h5>
3575<pre>
3576 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3577 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3578</pre>
3579</div>
3580
3581<!-- _______________________________________________________________________ -->
3582<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +00003583 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003584</div>
3585<div class="doc_text">
3586
3587<h5>Syntax:</h5>
3588<pre>
Reid Spencer753163d2007-07-31 14:40:14 +00003589 &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 +00003590</pre>
3591
3592<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +00003593<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003594unsigned integer equivalent of type <tt>ty2</tt>.
3595</p>
3596
3597<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +00003598<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemand4d45c22007-11-17 03:58:34 +00003599scalar or vector <a href="#t_floating">floating point</a> value, and a type
3600to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3601type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3602vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003603
3604<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +00003605<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003606<a href="#t_floating">floating point</a> operand into the nearest (rounding
3607towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3608the results are undefined.</p>
3609
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003610<h5>Example:</h5>
3611<pre>
Reid Spencer753163d2007-07-31 14:40:14 +00003612 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +00003613 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +00003614 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003615</pre>
3616</div>
3617
3618<!-- _______________________________________________________________________ -->
3619<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +00003620 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003621</div>
3622<div class="doc_text">
3623
3624<h5>Syntax:</h5>
3625<pre>
Reid Spencer51b07252006-11-09 23:03:26 +00003626 &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 +00003627</pre>
3628
3629<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003630<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003631<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003632</p>
3633
Chris Lattnera8292f32002-05-06 22:08:29 +00003634<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003635<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemand4d45c22007-11-17 03:58:34 +00003636scalar or vector <a href="#t_floating">floating point</a> value, and a type
3637to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3638type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3639vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003640
Chris Lattnera8292f32002-05-06 22:08:29 +00003641<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003642<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003643<a href="#t_floating">floating point</a> operand into the nearest (rounding
3644towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3645the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003646
Chris Lattner70de6632001-07-09 00:26:23 +00003647<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003648<pre>
Reid Spencer36a15422007-01-12 03:35:51 +00003649 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +00003650 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003651 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003652</pre>
3653</div>
3654
3655<!-- _______________________________________________________________________ -->
3656<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +00003657 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003658</div>
3659<div class="doc_text">
3660
3661<h5>Syntax:</h5>
3662<pre>
Reid Spencer51b07252006-11-09 23:03:26 +00003663 &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 +00003664</pre>
3665
3666<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003667<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003668integer and converts that value to the <tt>ty2</tt> type.</p>
3669
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003670<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +00003671<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3672scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3673to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3674type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3675floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003676
3677<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003678<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003679integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +00003680the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003681
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003682<h5>Example:</h5>
3683<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003684 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +00003685 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003686</pre>
3687</div>
3688
3689<!-- _______________________________________________________________________ -->
3690<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +00003691 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003692</div>
3693<div class="doc_text">
3694
3695<h5>Syntax:</h5>
3696<pre>
Reid Spencer51b07252006-11-09 23:03:26 +00003697 &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 +00003698</pre>
3699
3700<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003701<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003702integer and converts that value to the <tt>ty2</tt> type.</p>
3703
3704<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +00003705<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3706scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3707to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3708type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3709floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003710
3711<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +00003712<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003713integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +00003714the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003715
3716<h5>Example:</h5>
3717<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003718 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +00003719 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003720</pre>
3721</div>
3722
3723<!-- _______________________________________________________________________ -->
3724<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +00003725 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3726</div>
3727<div class="doc_text">
3728
3729<h5>Syntax:</h5>
3730<pre>
3731 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3732</pre>
3733
3734<h5>Overview:</h5>
3735<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3736the integer type <tt>ty2</tt>.</p>
3737
3738<h5>Arguments:</h5>
3739<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +00003740must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencerb7344ff2006-11-11 21:00:47 +00003741<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3742
3743<h5>Semantics:</h5>
3744<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3745<tt>ty2</tt> by interpreting the pointer value as an integer and either
3746truncating or zero extending that value to the size of the integer type. If
3747<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3748<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen222a8a42007-04-29 01:07:00 +00003749are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3750change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +00003751
3752<h5>Example:</h5>
3753<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +00003754 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3755 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +00003756</pre>
3757</div>
3758
3759<!-- _______________________________________________________________________ -->
3760<div class="doc_subsubsection">
3761 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3762</div>
3763<div class="doc_text">
3764
3765<h5>Syntax:</h5>
3766<pre>
3767 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3768</pre>
3769
3770<h5>Overview:</h5>
3771<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3772a pointer type, <tt>ty2</tt>.</p>
3773
3774<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +00003775<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +00003776value to cast, and a type to cast it to, which must be a
Anton Korobeynikova0554d92007-01-12 19:20:47 +00003777<a href="#t_pointer">pointer</a> type.
Reid Spencerb7344ff2006-11-11 21:00:47 +00003778
3779<h5>Semantics:</h5>
3780<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3781<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3782the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3783size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3784the size of a pointer then a zero extension is done. If they are the same size,
3785nothing is done (<i>no-op cast</i>).</p>
3786
3787<h5>Example:</h5>
3788<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +00003789 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3790 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3791 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +00003792</pre>
3793</div>
3794
3795<!-- _______________________________________________________________________ -->
3796<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +00003797 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003798</div>
3799<div class="doc_text">
3800
3801<h5>Syntax:</h5>
3802<pre>
Reid Spencer5b950642006-11-11 23:08:07 +00003803 &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 +00003804</pre>
3805
3806<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00003807
Reid Spencer5b950642006-11-11 23:08:07 +00003808<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003809<tt>ty2</tt> without changing any bits.</p>
3810
3811<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00003812
Reid Spencer5b950642006-11-11 23:08:07 +00003813<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +00003814a non-aggregate first class value, and a type to cast it to, which must also be
3815a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3816<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +00003817and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +00003818type is a pointer, the destination type must also be a pointer. This
3819instruction supports bitwise conversion of vectors to integers and to vectors
3820of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003821
3822<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +00003823<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +00003824<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3825this conversion. The conversion is done as if the <tt>value</tt> had been
3826stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3827converted to other pointer types with this instruction. To convert pointers to
3828other types, use the <a href="#i_inttoptr">inttoptr</a> or
3829<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +00003830
3831<h5>Example:</h5>
3832<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +00003833 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003834 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3835 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +00003836</pre>
Misha Brukman76307852003-11-08 01:05:38 +00003837</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00003838
Reid Spencer97c5fa42006-11-08 01:18:52 +00003839<!-- ======================================================================= -->
3840<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3841<div class="doc_text">
3842<p>The instructions in this category are the "miscellaneous"
3843instructions, which defy better classification.</p>
3844</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003845
3846<!-- _______________________________________________________________________ -->
3847<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3848</div>
3849<div class="doc_text">
3850<h5>Syntax:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +00003851<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003852</pre>
3853<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +00003854<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3855a vector of boolean values based on comparison
3856of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003857<h5>Arguments:</h5>
3858<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +00003859the condition code indicating the kind of comparison to perform. It is not
3860a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +00003861<ol>
3862 <li><tt>eq</tt>: equal</li>
3863 <li><tt>ne</tt>: not equal </li>
3864 <li><tt>ugt</tt>: unsigned greater than</li>
3865 <li><tt>uge</tt>: unsigned greater or equal</li>
3866 <li><tt>ult</tt>: unsigned less than</li>
3867 <li><tt>ule</tt>: unsigned less or equal</li>
3868 <li><tt>sgt</tt>: signed greater than</li>
3869 <li><tt>sge</tt>: signed greater or equal</li>
3870 <li><tt>slt</tt>: signed less than</li>
3871 <li><tt>sle</tt>: signed less or equal</li>
3872</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +00003873<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +00003874<a href="#t_pointer">pointer</a>
3875or integer <a href="#t_vector">vector</a> typed.
3876They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003877<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00003878<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerc828a0e2006-11-18 21:50:54 +00003879the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +00003880yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +00003881<ol>
3882 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3883 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3884 </li>
3885 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3886 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3887 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003888 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003889 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003890 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003891 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003892 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003893 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003894 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003895 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003896 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003897 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003898 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003899 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003900 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003901 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +00003902 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003903</ol>
3904<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +00003905values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +00003906<p>If the operands are integer vectors, then they are compared
3907element by element. The result is an <tt>i1</tt> vector with
3908the same number of elements as the values being compared.
3909Otherwise, the result is an <tt>i1</tt>.
3910</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003911
3912<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00003913<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3914 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3915 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3916 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3917 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3918 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003919</pre>
3920</div>
3921
3922<!-- _______________________________________________________________________ -->
3923<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3924</div>
3925<div class="doc_text">
3926<h5>Syntax:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +00003927<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003928</pre>
3929<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +00003930<p>The '<tt>fcmp</tt>' instruction returns a boolean value
3931or vector of boolean values based on comparison
3932of its operands.
3933<p>
3934If the operands are floating point scalars, then the result
3935type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
3936</p>
3937<p>If the operands are floating point vectors, then the result type
3938is a vector of boolean with the same number of elements as the
3939operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003940<h5>Arguments:</h5>
3941<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +00003942the condition code indicating the kind of comparison to perform. It is not
3943a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +00003944<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +00003945 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003946 <li><tt>oeq</tt>: ordered and equal</li>
3947 <li><tt>ogt</tt>: ordered and greater than </li>
3948 <li><tt>oge</tt>: ordered and greater than or equal</li>
3949 <li><tt>olt</tt>: ordered and less than </li>
3950 <li><tt>ole</tt>: ordered and less than or equal</li>
3951 <li><tt>one</tt>: ordered and not equal</li>
3952 <li><tt>ord</tt>: ordered (no nans)</li>
3953 <li><tt>ueq</tt>: unordered or equal</li>
3954 <li><tt>ugt</tt>: unordered or greater than </li>
3955 <li><tt>uge</tt>: unordered or greater than or equal</li>
3956 <li><tt>ult</tt>: unordered or less than </li>
3957 <li><tt>ule</tt>: unordered or less than or equal</li>
3958 <li><tt>une</tt>: unordered or not equal</li>
3959 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003960 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003961</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +00003962<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +00003963<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +00003964<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
3965either a <a href="#t_floating">floating point</a> type
3966or a <a href="#t_vector">vector</a> of floating point type.
3967They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +00003968<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00003969<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +00003970according to the condition code given as <tt>cond</tt>.
3971If the operands are vectors, then the vectors are compared
3972element by element.
3973Each comparison performed
3974always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +00003975<ol>
3976 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003977 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +00003978 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003979 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +00003980 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003981 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +00003982 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003983 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +00003984 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003985 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +00003986 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003987 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +00003988 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003989 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3990 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +00003991 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003992 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +00003993 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003994 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +00003995 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003996 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +00003997 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00003998 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +00003999 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00004000 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +00004001 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +00004002 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +00004003 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4004</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +00004005
4006<h5>Example:</h5>
4007<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +00004008 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4009 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4010 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +00004011</pre>
4012</div>
4013
Reid Spencer97c5fa42006-11-08 01:18:52 +00004014<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +00004015<div class="doc_subsubsection">
4016 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4017</div>
4018<div class="doc_text">
4019<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00004020<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemand2195702008-05-12 19:01:56 +00004021</pre>
4022<h5>Overview:</h5>
4023<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4024element-wise comparison of its two integer vector operands.</p>
4025<h5>Arguments:</h5>
4026<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4027the condition code indicating the kind of comparison to perform. It is not
4028a value, just a keyword. The possible condition code are:
4029<ol>
4030 <li><tt>eq</tt>: equal</li>
4031 <li><tt>ne</tt>: not equal </li>
4032 <li><tt>ugt</tt>: unsigned greater than</li>
4033 <li><tt>uge</tt>: unsigned greater or equal</li>
4034 <li><tt>ult</tt>: unsigned less than</li>
4035 <li><tt>ule</tt>: unsigned less or equal</li>
4036 <li><tt>sgt</tt>: signed greater than</li>
4037 <li><tt>sge</tt>: signed greater or equal</li>
4038 <li><tt>slt</tt>: signed less than</li>
4039 <li><tt>sle</tt>: signed less or equal</li>
4040</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +00004041<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +00004042<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4043<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00004044<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +00004045according to the condition code given as <tt>cond</tt>. The comparison yields a
4046<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4047identical type as the values being compared. The most significant bit in each
4048element is 1 if the element-wise comparison evaluates to true, and is 0
4049otherwise. All other bits of the result are undefined. The condition codes
4050are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
4051instruction</a>.
4052
4053<h5>Example:</h5>
4054<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004055 &lt;result&gt; = vicmp eq &lt;2 x i32&gt; &lt; i32 4, i32 0&gt;, &lt; i32 5, i32 0&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4056 &lt;result&gt; = vicmp ult &lt;2 x i8 &gt; &lt; i8 1, i8 2&gt;, &lt; i8 2, i8 2 &gt; <i>; yields: result=&lt;2 x i8&gt; &lt; i8 -1, i8 0 &gt;</i>
Nate Begemand2195702008-05-12 19:01:56 +00004057</pre>
4058</div>
4059
4060<!-- _______________________________________________________________________ -->
4061<div class="doc_subsubsection">
4062 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4063</div>
4064<div class="doc_text">
4065<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00004066<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemand2195702008-05-12 19:01:56 +00004067<h5>Overview:</h5>
4068<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4069element-wise comparison of its two floating point vector operands. The output
4070elements have the same width as the input elements.</p>
4071<h5>Arguments:</h5>
4072<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4073the condition code indicating the kind of comparison to perform. It is not
4074a value, just a keyword. The possible condition code are:
4075<ol>
4076 <li><tt>false</tt>: no comparison, always returns false</li>
4077 <li><tt>oeq</tt>: ordered and equal</li>
4078 <li><tt>ogt</tt>: ordered and greater than </li>
4079 <li><tt>oge</tt>: ordered and greater than or equal</li>
4080 <li><tt>olt</tt>: ordered and less than </li>
4081 <li><tt>ole</tt>: ordered and less than or equal</li>
4082 <li><tt>one</tt>: ordered and not equal</li>
4083 <li><tt>ord</tt>: ordered (no nans)</li>
4084 <li><tt>ueq</tt>: unordered or equal</li>
4085 <li><tt>ugt</tt>: unordered or greater than </li>
4086 <li><tt>uge</tt>: unordered or greater than or equal</li>
4087 <li><tt>ult</tt>: unordered or less than </li>
4088 <li><tt>ule</tt>: unordered or less than or equal</li>
4089 <li><tt>une</tt>: unordered or not equal</li>
4090 <li><tt>uno</tt>: unordered (either nans)</li>
4091 <li><tt>true</tt>: no comparison, always returns true</li>
4092</ol>
4093<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4094<a href="#t_floating">floating point</a> typed. They must also be identical
4095types.</p>
4096<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +00004097<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +00004098according to the condition code given as <tt>cond</tt>. The comparison yields a
4099<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4100an identical number of elements as the values being compared, and each element
4101having identical with to the width of the floating point elements. The most
4102significant bit in each element is 1 if the element-wise comparison evaluates to
4103true, and is 0 otherwise. All other bits of the result are undefined. The
4104condition codes are evaluated identically to the
4105<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
4106
4107<h5>Example:</h5>
4108<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004109 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4110 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt; <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
Nate Begemand2195702008-05-12 19:01:56 +00004111</pre>
4112</div>
4113
4114<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004115<div class="doc_subsubsection">
4116 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4117</div>
4118
Reid Spencer97c5fa42006-11-08 01:18:52 +00004119<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004120
Reid Spencer97c5fa42006-11-08 01:18:52 +00004121<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004122
Reid Spencer97c5fa42006-11-08 01:18:52 +00004123<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4124<h5>Overview:</h5>
4125<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4126the SSA graph representing the function.</p>
4127<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004128
Jeff Cohen222a8a42007-04-29 01:07:00 +00004129<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +00004130field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4131as arguments, with one pair for each predecessor basic block of the
4132current block. Only values of <a href="#t_firstclass">first class</a>
4133type may be used as the value arguments to the PHI node. Only labels
4134may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004135
Reid Spencer97c5fa42006-11-08 01:18:52 +00004136<p>There must be no non-phi instructions between the start of a basic
4137block and the PHI instructions: i.e. PHI instructions must be first in
4138a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004139
Reid Spencer97c5fa42006-11-08 01:18:52 +00004140<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004141
Jeff Cohen222a8a42007-04-29 01:07:00 +00004142<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4143specified by the pair corresponding to the predecessor basic block that executed
4144just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004145
Reid Spencer97c5fa42006-11-08 01:18:52 +00004146<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004147<pre>
4148Loop: ; Infinite loop that counts from 0 on up...
4149 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4150 %nextindvar = add i32 %indvar, 1
4151 br label %Loop
4152</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +00004153</div>
4154
Chris Lattnerb53c28d2004-03-12 05:50:16 +00004155<!-- _______________________________________________________________________ -->
4156<div class="doc_subsubsection">
4157 <a name="i_select">'<tt>select</tt>' Instruction</a>
4158</div>
4159
4160<div class="doc_text">
4161
4162<h5>Syntax:</h5>
4163
4164<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +00004165 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4166
4167 <i>selty</i> is either i1 or {&lt;N x i1&gt}
Chris Lattnerb53c28d2004-03-12 05:50:16 +00004168</pre>
4169
4170<h5>Overview:</h5>
4171
4172<p>
4173The '<tt>select</tt>' instruction is used to choose one value based on a
4174condition, without branching.
4175</p>
4176
4177
4178<h5>Arguments:</h5>
4179
4180<p>
Dan Gohmanc579d972008-09-09 01:02:47 +00004181The '<tt>select</tt>' instruction requires an 'i1' value or
4182a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004183condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +00004184type. If the val1/val2 are vectors and
4185the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +00004186individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +00004187</p>
4188
4189<h5>Semantics:</h5>
4190
4191<p>
Dan Gohmanc579d972008-09-09 01:02:47 +00004192If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +00004193value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +00004194</p>
Dan Gohmanc579d972008-09-09 01:02:47 +00004195<p>
4196If the condition is a vector of i1, then the value arguments must
4197be vectors of the same size, and the selection is done element
4198by element.
4199</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00004200
4201<h5>Example:</h5>
4202
4203<pre>
Reid Spencer36a15422007-01-12 03:35:51 +00004204 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +00004205</pre>
4206</div>
4207
Robert Bocchinof72fdfe2006-01-15 20:48:27 +00004208
4209<!-- _______________________________________________________________________ -->
4210<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +00004211 <a name="i_call">'<tt>call</tt>' Instruction</a>
4212</div>
4213
Misha Brukman76307852003-11-08 01:05:38 +00004214<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +00004215
Chris Lattner2f7c9632001-06-06 20:29:01 +00004216<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +00004217<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +00004218 &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 +00004219</pre>
4220
Chris Lattner2f7c9632001-06-06 20:29:01 +00004221<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +00004222
Misha Brukman76307852003-11-08 01:05:38 +00004223<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +00004224
Chris Lattner2f7c9632001-06-06 20:29:01 +00004225<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +00004226
Misha Brukman76307852003-11-08 01:05:38 +00004227<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +00004228
Chris Lattnera8292f32002-05-06 22:08:29 +00004229<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +00004230 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +00004231 <p>The optional "tail" marker indicates whether the callee function accesses
4232 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +00004233 function call is eligible for tail call optimization. Note that calls may
4234 be marked "tail" even if they do not occur before a <a
4235 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner48b383b02003-11-25 01:02:51 +00004236 </li>
4237 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +00004238 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +00004239 convention</a> the call should use. If none is specified, the call defaults
4240 to using C calling conventions.
4241 </li>
4242 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +00004243 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4244 the type of the return value. Functions that return no value are marked
4245 <tt><a href="#t_void">void</a></tt>.</p>
4246 </li>
4247 <li>
4248 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4249 value being invoked. The argument types must match the types implied by
4250 this signature. This type can be omitted if the function is not varargs
4251 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +00004252 </li>
4253 <li>
4254 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4255 be invoked. In most cases, this is a direct function invocation, but
4256 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +00004257 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00004258 </li>
4259 <li>
4260 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +00004261 function signature argument types. All arguments must be of
4262 <a href="#t_firstclass">first class</a> type. If the function signature
4263 indicates the function accepts a variable number of arguments, the extra
4264 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +00004265 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +00004266</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +00004267
Chris Lattner2f7c9632001-06-06 20:29:01 +00004268<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +00004269
Chris Lattner48b383b02003-11-25 01:02:51 +00004270<p>The '<tt>call</tt>' instruction is used to cause control flow to
4271transfer to a specified function, with its incoming arguments bound to
4272the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4273instruction in the called function, control flow continues with the
4274instruction after the function call, and the return value of the
Chris Lattnerfb7c88d2008-03-21 17:24:17 +00004275function is bound to the result argument. If the callee returns multiple
4276values then the return values of the function are only accessible through
4277the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +00004278
Chris Lattner2f7c9632001-06-06 20:29:01 +00004279<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +00004280
4281<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +00004282 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +00004283 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4284 %X = tail call i32 @foo() <i>; yields i32</i>
4285 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4286 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +00004287
4288 %struct.A = type { i32, i8 }
Chris Lattnerfb7c88d2008-03-21 17:24:17 +00004289 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
4290 %gr = getresult %struct.A %r, 0 <i>; yields i32</i>
4291 %gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattnere23c1392005-05-06 05:47:36 +00004292</pre>
4293
Misha Brukman76307852003-11-08 01:05:38 +00004294</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004295
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004296<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +00004297<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +00004298 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004299</div>
4300
Misha Brukman76307852003-11-08 01:05:38 +00004301<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +00004302
Chris Lattner26ca62e2003-10-18 05:51:36 +00004303<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004304
4305<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004306 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +00004307</pre>
4308
Chris Lattner26ca62e2003-10-18 05:51:36 +00004309<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004310
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004311<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +00004312the "variable argument" area of a function call. It is used to implement the
4313<tt>va_arg</tt> macro in C.</p>
4314
Chris Lattner26ca62e2003-10-18 05:51:36 +00004315<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004316
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004317<p>This instruction takes a <tt>va_list*</tt> value and the type of
4318the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +00004319increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004320actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004321
Chris Lattner26ca62e2003-10-18 05:51:36 +00004322<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004323
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004324<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4325type from the specified <tt>va_list</tt> and causes the
4326<tt>va_list</tt> to point to the next argument. For more information,
4327see the variable argument handling <a href="#int_varargs">Intrinsic
4328Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004329
4330<p>It is legal for this instruction to be called in a function which does not
4331take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +00004332function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004333
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004334<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +00004335href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +00004336argument.</p>
4337
Chris Lattner26ca62e2003-10-18 05:51:36 +00004338<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +00004339
4340<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4341
Misha Brukman76307852003-11-08 01:05:38 +00004342</div>
Chris Lattner941515c2004-01-06 05:31:32 +00004343
Devang Pateld6cff512008-03-10 20:49:15 +00004344<!-- _______________________________________________________________________ -->
4345<div class="doc_subsubsection">
4346 <a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
4347</div>
4348
4349<div class="doc_text">
4350
4351<h5>Syntax:</h5>
4352<pre>
Chris Lattner141b6132008-03-21 17:20:51 +00004353 &lt;resultval&gt; = getresult &lt;type&gt; &lt;retval&gt;, &lt;index&gt;
Devang Pateld6cff512008-03-10 20:49:15 +00004354</pre>
Chris Lattner141b6132008-03-21 17:20:51 +00004355
Devang Pateld6cff512008-03-10 20:49:15 +00004356<h5>Overview:</h5>
4357
4358<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner141b6132008-03-21 17:20:51 +00004359from a '<tt><a href="#i_call">call</a></tt>'
4360or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
4361results.</p>
Devang Pateld6cff512008-03-10 20:49:15 +00004362
4363<h5>Arguments:</h5>
4364
Chris Lattner141b6132008-03-21 17:20:51 +00004365<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner1a640a62008-04-23 04:06:52 +00004366first argument, or an undef value. The value must have <a
4367href="#t_struct">structure type</a>. The second argument is a constant
4368unsigned index value which must be in range for the number of values returned
4369by the call.</p>
Devang Pateld6cff512008-03-10 20:49:15 +00004370
4371<h5>Semantics:</h5>
4372
Chris Lattner141b6132008-03-21 17:20:51 +00004373<p>The '<tt>getresult</tt>' instruction extracts the element identified by
4374'<tt>index</tt>' from the aggregate value.</p>
Devang Pateld6cff512008-03-10 20:49:15 +00004375
4376<h5>Example:</h5>
4377
4378<pre>
4379 %struct.A = type { i32, i8 }
4380
4381 %r = call %struct.A @foo()
Chris Lattner141b6132008-03-21 17:20:51 +00004382 %gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
4383 %gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Pateld6cff512008-03-10 20:49:15 +00004384 add i32 %gr, 42
4385 add i8 %gr1, 41
4386</pre>
4387
4388</div>
4389
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004390<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +00004391<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4392<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +00004393
Misha Brukman76307852003-11-08 01:05:38 +00004394<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +00004395
4396<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +00004397well known names and semantics and are required to follow certain restrictions.
4398Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +00004399language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +00004400adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +00004401
John Criswell88190562005-05-16 16:17:45 +00004402<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +00004403prefix is reserved in LLVM for intrinsic names; thus, function names may not
4404begin with this prefix. Intrinsic functions must always be external functions:
4405you cannot define the body of intrinsic functions. Intrinsic functions may
4406only be used in call or invoke instructions: it is illegal to take the address
4407of an intrinsic function. Additionally, because intrinsic functions are part
4408of the LLVM language, it is required if any are added that they be documented
4409here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +00004410
Chandler Carruth7132e002007-08-04 01:51:18 +00004411<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4412a family of functions that perform the same operation but on different data
4413types. Because LLVM can represent over 8 million different integer types,
4414overloading is used commonly to allow an intrinsic function to operate on any
4415integer type. One or more of the argument types or the result type can be
4416overloaded to accept any integer type. Argument types may also be defined as
4417exactly matching a previous argument's type or the result type. This allows an
4418intrinsic function which accepts multiple arguments, but needs all of them to
4419be of the same type, to only be overloaded with respect to a single argument or
4420the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +00004421
Chandler Carruth7132e002007-08-04 01:51:18 +00004422<p>Overloaded intrinsics will have the names of its overloaded argument types
4423encoded into its function name, each preceded by a period. Only those types
4424which are overloaded result in a name suffix. Arguments whose type is matched
4425against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4426take an integer of any width and returns an integer of exactly the same integer
4427width. This leads to a family of functions such as
4428<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4429Only one type, the return type, is overloaded, and only one type suffix is
4430required. Because the argument's type is matched against the return type, it
4431does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +00004432
4433<p>To learn how to add an intrinsic function, please see the
4434<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +00004435</p>
4436
Misha Brukman76307852003-11-08 01:05:38 +00004437</div>
Chris Lattner941515c2004-01-06 05:31:32 +00004438
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004439<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +00004440<div class="doc_subsection">
4441 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4442</div>
4443
Misha Brukman76307852003-11-08 01:05:38 +00004444<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +00004445
Misha Brukman76307852003-11-08 01:05:38 +00004446<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +00004447 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +00004448intrinsic functions. These functions are related to the similarly
4449named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004450
Chris Lattner48b383b02003-11-25 01:02:51 +00004451<p>All of these functions operate on arguments that use a
4452target-specific value type "<tt>va_list</tt>". The LLVM assembly
4453language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +00004454transformations should be prepared to handle these functions regardless of
4455the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004456
Chris Lattner30b868d2006-05-15 17:26:46 +00004457<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner48b383b02003-11-25 01:02:51 +00004458instruction and the variable argument handling intrinsic functions are
4459used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004460
Bill Wendling3716c5d2007-05-29 09:04:49 +00004461<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +00004462<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +00004463define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +00004464 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +00004465 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004466 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +00004467 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +00004468
4469 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +00004470 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +00004471
4472 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +00004473 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004474 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +00004475 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +00004476 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +00004477
4478 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +00004479 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00004480 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +00004481}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +00004482
4483declare void @llvm.va_start(i8*)
4484declare void @llvm.va_copy(i8*, i8*)
4485declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +00004486</pre>
Misha Brukman76307852003-11-08 01:05:38 +00004487</div>
Chris Lattner941515c2004-01-06 05:31:32 +00004488
Bill Wendling3716c5d2007-05-29 09:04:49 +00004489</div>
4490
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004491<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +00004492<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004493 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +00004494</div>
4495
4496
Misha Brukman76307852003-11-08 01:05:38 +00004497<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004498<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004499<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004500<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004501<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
4502<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4503href="#i_va_arg">va_arg</a></tt>.</p>
4504
4505<h5>Arguments:</h5>
4506
4507<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
4508
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004509<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004510
4511<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
4512macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +00004513<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004514<tt>va_arg</tt> will produce the first variable argument passed to the function.
4515Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen222a8a42007-04-29 01:07:00 +00004516last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004517
Misha Brukman76307852003-11-08 01:05:38 +00004518</div>
Chris Lattner941515c2004-01-06 05:31:32 +00004519
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004520<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +00004521<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004522 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +00004523</div>
4524
Misha Brukman76307852003-11-08 01:05:38 +00004525<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004526<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00004527<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004528<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004529
Jeff Cohen222a8a42007-04-29 01:07:00 +00004530<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +00004531which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner48b383b02003-11-25 01:02:51 +00004532or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004533
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004534<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004535
Jeff Cohen222a8a42007-04-29 01:07:00 +00004536<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004537
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004538<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004539
Misha Brukman76307852003-11-08 01:05:38 +00004540<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen222a8a42007-04-29 01:07:00 +00004541macro available in C. In a target-dependent way, it destroys the
4542<tt>va_list</tt> element to which the argument points. Calls to <a
4543href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4544<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4545<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +00004546
Misha Brukman76307852003-11-08 01:05:38 +00004547</div>
Chris Lattner941515c2004-01-06 05:31:32 +00004548
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004549<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +00004550<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004551 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +00004552</div>
4553
Misha Brukman76307852003-11-08 01:05:38 +00004554<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +00004555
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004556<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004557
4558<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00004559 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +00004560</pre>
4561
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004562<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004563
Jeff Cohen222a8a42007-04-29 01:07:00 +00004564<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4565from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004566
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004567<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004568
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004569<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth5305ea52005-06-22 20:38:11 +00004570The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +00004571
Chris Lattner757528b0b2004-05-23 21:06:01 +00004572
Chris Lattnerbd64b4e2003-05-08 04:57:36 +00004573<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004574
Jeff Cohen222a8a42007-04-29 01:07:00 +00004575<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4576macro available in C. In a target-dependent way, it copies the source
4577<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4578intrinsic is necessary because the <tt><a href="#int_va_start">
4579llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4580example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004581
Misha Brukman76307852003-11-08 01:05:38 +00004582</div>
Chris Lattner941515c2004-01-06 05:31:32 +00004583
Chris Lattnerfee11462004-02-12 17:01:32 +00004584<!-- ======================================================================= -->
4585<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +00004586 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4587</div>
4588
4589<div class="doc_text">
4590
4591<p>
4592LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +00004593Collection</a> (GC) requires the implementation and generation of these
4594intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +00004595These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +00004596stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +00004597href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +00004598Front-ends for type-safe garbage collected languages should generate these
4599intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4600href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4601</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +00004602
4603<p>The garbage collection intrinsics only operate on objects in the generic
4604 address space (address space zero).</p>
4605
Chris Lattner757528b0b2004-05-23 21:06:01 +00004606</div>
4607
4608<!-- _______________________________________________________________________ -->
4609<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004610 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004611</div>
4612
4613<div class="doc_text">
4614
4615<h5>Syntax:</h5>
4616
4617<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004618 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +00004619</pre>
4620
4621<h5>Overview:</h5>
4622
John Criswelldfe6a862004-12-10 15:51:16 +00004623<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner757528b0b2004-05-23 21:06:01 +00004624the code generator, and allows some metadata to be associated with it.</p>
4625
4626<h5>Arguments:</h5>
4627
4628<p>The first argument specifies the address of a stack object that contains the
4629root pointer. The second pointer (which must be either a constant or a global
4630value address) contains the meta-data to be associated with the root.</p>
4631
4632<h5>Semantics:</h5>
4633
Chris Lattner851b7712008-04-24 05:59:56 +00004634<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner757528b0b2004-05-23 21:06:01 +00004635location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +00004636the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4637intrinsic may only be used in a function which <a href="#gc">specifies a GC
4638algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004639
4640</div>
4641
4642
4643<!-- _______________________________________________________________________ -->
4644<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004645 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004646</div>
4647
4648<div class="doc_text">
4649
4650<h5>Syntax:</h5>
4651
4652<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004653 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +00004654</pre>
4655
4656<h5>Overview:</h5>
4657
4658<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4659locations, allowing garbage collector implementations that require read
4660barriers.</p>
4661
4662<h5>Arguments:</h5>
4663
Chris Lattnerf9228072006-03-14 20:02:51 +00004664<p>The second argument is the address to read from, which should be an address
4665allocated from the garbage collector. The first object is a pointer to the
4666start of the referenced object, if needed by the language runtime (otherwise
4667null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004668
4669<h5>Semantics:</h5>
4670
4671<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4672instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +00004673garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4674may only be used in a function which <a href="#gc">specifies a GC
4675algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004676
4677</div>
4678
4679
4680<!-- _______________________________________________________________________ -->
4681<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004682 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004683</div>
4684
4685<div class="doc_text">
4686
4687<h5>Syntax:</h5>
4688
4689<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004690 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +00004691</pre>
4692
4693<h5>Overview:</h5>
4694
4695<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4696locations, allowing garbage collector implementations that require write
4697barriers (such as generational or reference counting collectors).</p>
4698
4699<h5>Arguments:</h5>
4700
Chris Lattnerf9228072006-03-14 20:02:51 +00004701<p>The first argument is the reference to store, the second is the start of the
4702object to store it to, and the third is the address of the field of Obj to
4703store to. If the runtime does not require a pointer to the object, Obj may be
4704null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004705
4706<h5>Semantics:</h5>
4707
4708<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4709instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +00004710garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4711may only be used in a function which <a href="#gc">specifies a GC
4712algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +00004713
4714</div>
4715
4716
4717
4718<!-- ======================================================================= -->
4719<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +00004720 <a name="int_codegen">Code Generator Intrinsics</a>
4721</div>
4722
4723<div class="doc_text">
4724<p>
4725These intrinsics are provided by LLVM to expose special features that may only
4726be implemented with code generator support.
4727</p>
4728
4729</div>
4730
4731<!-- _______________________________________________________________________ -->
4732<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004733 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +00004734</div>
4735
4736<div class="doc_text">
4737
4738<h5>Syntax:</h5>
4739<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00004740 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +00004741</pre>
4742
4743<h5>Overview:</h5>
4744
4745<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +00004746The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4747target-specific value indicating the return address of the current function
4748or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +00004749</p>
4750
4751<h5>Arguments:</h5>
4752
4753<p>
4754The argument to this intrinsic indicates which function to return the address
4755for. Zero indicates the calling function, one indicates its caller, etc. The
4756argument is <b>required</b> to be a constant integer value.
4757</p>
4758
4759<h5>Semantics:</h5>
4760
4761<p>
4762The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4763the return address of the specified call frame, or zero if it cannot be
4764identified. The value returned by this intrinsic is likely to be incorrect or 0
4765for arguments other than zero, so it should only be used for debugging purposes.
4766</p>
4767
4768<p>
4769Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +00004770aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +00004771source-language caller.
4772</p>
4773</div>
4774
4775
4776<!-- _______________________________________________________________________ -->
4777<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004778 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +00004779</div>
4780
4781<div class="doc_text">
4782
4783<h5>Syntax:</h5>
4784<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004785 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +00004786</pre>
4787
4788<h5>Overview:</h5>
4789
4790<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +00004791The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4792target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +00004793</p>
4794
4795<h5>Arguments:</h5>
4796
4797<p>
4798The argument to this intrinsic indicates which function to return the frame
4799pointer for. Zero indicates the calling function, one indicates its caller,
4800etc. The argument is <b>required</b> to be a constant integer value.
4801</p>
4802
4803<h5>Semantics:</h5>
4804
4805<p>
4806The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4807the frame address of the specified call frame, or zero if it cannot be
4808identified. The value returned by this intrinsic is likely to be incorrect or 0
4809for arguments other than zero, so it should only be used for debugging purposes.
4810</p>
4811
4812<p>
4813Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +00004814aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +00004815source-language caller.
4816</p>
4817</div>
4818
Chris Lattnerc8a2c222005-02-28 19:24:19 +00004819<!-- _______________________________________________________________________ -->
4820<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004821 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +00004822</div>
4823
4824<div class="doc_text">
4825
4826<h5>Syntax:</h5>
4827<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004828 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +00004829</pre>
4830
4831<h5>Overview:</h5>
4832
4833<p>
4834The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +00004835the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +00004836<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4837features like scoped automatic variable sized arrays in C99.
4838</p>
4839
4840<h5>Semantics:</h5>
4841
4842<p>
4843This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +00004844href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +00004845<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4846<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4847state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4848practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4849that were allocated after the <tt>llvm.stacksave</tt> was executed.
4850</p>
4851
4852</div>
4853
4854<!-- _______________________________________________________________________ -->
4855<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004856 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +00004857</div>
4858
4859<div class="doc_text">
4860
4861<h5>Syntax:</h5>
4862<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00004863 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +00004864</pre>
4865
4866<h5>Overview:</h5>
4867
4868<p>
4869The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4870the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +00004871href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +00004872useful for implementing language features like scoped automatic variable sized
4873arrays in C99.
4874</p>
4875
4876<h5>Semantics:</h5>
4877
4878<p>
Reid Spencer96a5f022007-04-04 02:42:35 +00004879See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +00004880</p>
4881
4882</div>
4883
4884
4885<!-- _______________________________________________________________________ -->
4886<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004887 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +00004888</div>
4889
4890<div class="doc_text">
4891
4892<h5>Syntax:</h5>
4893<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004894 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +00004895</pre>
4896
4897<h5>Overview:</h5>
4898
4899
4900<p>
4901The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +00004902a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4903no
4904effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +00004905characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +00004906</p>
4907
4908<h5>Arguments:</h5>
4909
4910<p>
4911<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4912determining if the fetch should be for a read (0) or write (1), and
4913<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +00004914locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +00004915<tt>locality</tt> arguments must be constant integers.
4916</p>
4917
4918<h5>Semantics:</h5>
4919
4920<p>
4921This intrinsic does not modify the behavior of the program. In particular,
4922prefetches cannot trap and do not produce a value. On targets that support this
4923intrinsic, the prefetch can provide hints to the processor cache for better
4924performance.
4925</p>
4926
4927</div>
4928
Andrew Lenharthb4427912005-03-28 20:05:49 +00004929<!-- _______________________________________________________________________ -->
4930<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004931 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +00004932</div>
4933
4934<div class="doc_text">
4935
4936<h5>Syntax:</h5>
4937<pre>
Chris Lattner12477732007-09-21 17:30:40 +00004938 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +00004939</pre>
4940
4941<h5>Overview:</h5>
4942
4943
4944<p>
John Criswell88190562005-05-16 16:17:45 +00004945The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +00004946(PC) in a region of
4947code to simulators and other tools. The method is target specific, but it is
4948expected that the marker will use exported symbols to transmit the PC of the
4949marker.
4950The marker makes no guarantees that it will remain with any specific instruction
4951after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +00004952optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +00004953correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +00004954</p>
4955
4956<h5>Arguments:</h5>
4957
4958<p>
4959<tt>id</tt> is a numerical id identifying the marker.
4960</p>
4961
4962<h5>Semantics:</h5>
4963
4964<p>
4965This intrinsic does not modify the behavior of the program. Backends that do not
4966support this intrinisic may ignore it.
4967</p>
4968
4969</div>
4970
Andrew Lenharth01aa5632005-11-11 16:47:30 +00004971<!-- _______________________________________________________________________ -->
4972<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00004973 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +00004974</div>
4975
4976<div class="doc_text">
4977
4978<h5>Syntax:</h5>
4979<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00004980 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +00004981</pre>
4982
4983<h5>Overview:</h5>
4984
4985
4986<p>
4987The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4988counter register (or similar low latency, high accuracy clocks) on those targets
4989that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4990As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4991should only be used for small timings.
4992</p>
4993
4994<h5>Semantics:</h5>
4995
4996<p>
4997When directly supported, reading the cycle counter should not modify any memory.
4998Implementations are allowed to either return a application specific value or a
4999system wide value. On backends without support, this is lowered to a constant 0.
5000</p>
5001
5002</div>
5003
Chris Lattner3649c3a2004-02-14 04:08:35 +00005004<!-- ======================================================================= -->
5005<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +00005006 <a name="int_libc">Standard C Library Intrinsics</a>
5007</div>
5008
5009<div class="doc_text">
5010<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +00005011LLVM provides intrinsics for a few important standard C library functions.
5012These intrinsics allow source-language front-ends to pass information about the
5013alignment of the pointer arguments to the code generator, providing opportunity
5014for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +00005015</p>
5016
5017</div>
5018
5019<!-- _______________________________________________________________________ -->
5020<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00005021 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +00005022</div>
5023
5024<div class="doc_text">
5025
5026<h5>Syntax:</h5>
5027<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005028 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005029 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005030 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005031 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +00005032</pre>
5033
5034<h5>Overview:</h5>
5035
5036<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005037The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +00005038location to the destination location.
5039</p>
5040
5041<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005042Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5043intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +00005044</p>
5045
5046<h5>Arguments:</h5>
5047
5048<p>
5049The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +00005050the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +00005051specifying the number of bytes to copy, and the fourth argument is the alignment
5052of the source and destination locations.
5053</p>
5054
Chris Lattner4c67c482004-02-12 21:18:15 +00005055<p>
5056If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +00005057the caller guarantees that both the source and destination pointers are aligned
5058to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +00005059</p>
5060
Chris Lattnerfee11462004-02-12 17:01:32 +00005061<h5>Semantics:</h5>
5062
5063<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005064The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +00005065location to the destination location, which are not allowed to overlap. It
5066copies "len" bytes of memory over. If the argument is known to be aligned to
5067some boundary, this can be specified as the fourth argument, otherwise it should
5068be set to 0 or 1.
5069</p>
5070</div>
5071
5072
Chris Lattnerf30152e2004-02-12 18:10:10 +00005073<!-- _______________________________________________________________________ -->
5074<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00005075 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +00005076</div>
5077
5078<div class="doc_text">
5079
5080<h5>Syntax:</h5>
5081<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005082 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005083 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005084 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005085 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +00005086</pre>
5087
5088<h5>Overview:</h5>
5089
5090<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005091The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5092location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +00005093'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +00005094</p>
5095
5096<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005097Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5098intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +00005099</p>
5100
5101<h5>Arguments:</h5>
5102
5103<p>
5104The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +00005105the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +00005106specifying the number of bytes to copy, and the fourth argument is the alignment
5107of the source and destination locations.
5108</p>
5109
Chris Lattner4c67c482004-02-12 21:18:15 +00005110<p>
5111If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +00005112the caller guarantees that the source and destination pointers are aligned to
5113that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +00005114</p>
5115
Chris Lattnerf30152e2004-02-12 18:10:10 +00005116<h5>Semantics:</h5>
5117
5118<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005119The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +00005120location to the destination location, which may overlap. It
5121copies "len" bytes of memory over. If the argument is known to be aligned to
5122some boundary, this can be specified as the fourth argument, otherwise it should
5123be set to 0 or 1.
5124</p>
5125</div>
5126
Chris Lattner941515c2004-01-06 05:31:32 +00005127
Chris Lattner3649c3a2004-02-14 04:08:35 +00005128<!-- _______________________________________________________________________ -->
5129<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00005130 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +00005131</div>
5132
5133<div class="doc_text">
5134
5135<h5>Syntax:</h5>
5136<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005137 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005138 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005139 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005140 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +00005141</pre>
5142
5143<h5>Overview:</h5>
5144
5145<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005146The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +00005147byte value.
5148</p>
5149
5150<p>
5151Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5152does not return a value, and takes an extra alignment argument.
5153</p>
5154
5155<h5>Arguments:</h5>
5156
5157<p>
5158The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +00005159byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +00005160argument specifying the number of bytes to fill, and the fourth argument is the
5161known alignment of destination location.
5162</p>
5163
5164<p>
5165If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +00005166the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +00005167</p>
5168
5169<h5>Semantics:</h5>
5170
5171<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +00005172The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5173the
Chris Lattner3649c3a2004-02-14 04:08:35 +00005174destination location. If the argument is known to be aligned to some boundary,
5175this can be specified as the fourth argument, otherwise it should be set to 0 or
51761.
5177</p>
5178</div>
5179
5180
Chris Lattner3b4f4372004-06-11 02:28:03 +00005181<!-- _______________________________________________________________________ -->
5182<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00005183 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +00005184</div>
5185
5186<div class="doc_text">
5187
5188<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +00005189<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +00005190floating point or vector of floating point type. Not all targets support all
5191types however.
Chris Lattner8a8f2e52005-07-21 01:29:16 +00005192<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +00005193 declare float @llvm.sqrt.f32(float %Val)
5194 declare double @llvm.sqrt.f64(double %Val)
5195 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5196 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5197 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +00005198</pre>
5199
5200<h5>Overview:</h5>
5201
5202<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +00005203The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +00005204returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +00005205<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +00005206negative numbers other than -0.0 (which allows for better optimization, because
5207there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5208defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +00005209</p>
5210
5211<h5>Arguments:</h5>
5212
5213<p>
5214The argument and return value are floating point numbers of the same type.
5215</p>
5216
5217<h5>Semantics:</h5>
5218
5219<p>
Dan Gohman33988db2007-07-16 14:37:41 +00005220This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +00005221floating point number.
5222</p>
5223</div>
5224
Chris Lattner33b73f92006-09-08 06:34:02 +00005225<!-- _______________________________________________________________________ -->
5226<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00005227 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +00005228</div>
5229
5230<div class="doc_text">
5231
5232<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +00005233<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +00005234floating point or vector of floating point type. Not all targets support all
5235types however.
Chris Lattner33b73f92006-09-08 06:34:02 +00005236<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +00005237 declare float @llvm.powi.f32(float %Val, i32 %power)
5238 declare double @llvm.powi.f64(double %Val, i32 %power)
5239 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5240 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5241 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +00005242</pre>
5243
5244<h5>Overview:</h5>
5245
5246<p>
5247The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5248specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +00005249multiplications is not defined. When a vector of floating point type is
5250used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +00005251</p>
5252
5253<h5>Arguments:</h5>
5254
5255<p>
5256The second argument is an integer power, and the first is a value to raise to
5257that power.
5258</p>
5259
5260<h5>Semantics:</h5>
5261
5262<p>
5263This function returns the first value raised to the second power with an
5264unspecified sequence of rounding operations.</p>
5265</div>
5266
Dan Gohmanb6324c12007-10-15 20:30:11 +00005267<!-- _______________________________________________________________________ -->
5268<div class="doc_subsubsection">
5269 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5270</div>
5271
5272<div class="doc_text">
5273
5274<h5>Syntax:</h5>
5275<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5276floating point or vector of floating point type. Not all targets support all
5277types however.
5278<pre>
5279 declare float @llvm.sin.f32(float %Val)
5280 declare double @llvm.sin.f64(double %Val)
5281 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5282 declare fp128 @llvm.sin.f128(fp128 %Val)
5283 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5284</pre>
5285
5286<h5>Overview:</h5>
5287
5288<p>
5289The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5290</p>
5291
5292<h5>Arguments:</h5>
5293
5294<p>
5295The argument and return value are floating point numbers of the same type.
5296</p>
5297
5298<h5>Semantics:</h5>
5299
5300<p>
5301This function returns the sine of the specified operand, returning the
5302same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +00005303conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +00005304</div>
5305
5306<!-- _______________________________________________________________________ -->
5307<div class="doc_subsubsection">
5308 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5309</div>
5310
5311<div class="doc_text">
5312
5313<h5>Syntax:</h5>
5314<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5315floating point or vector of floating point type. Not all targets support all
5316types however.
5317<pre>
5318 declare float @llvm.cos.f32(float %Val)
5319 declare double @llvm.cos.f64(double %Val)
5320 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5321 declare fp128 @llvm.cos.f128(fp128 %Val)
5322 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5323</pre>
5324
5325<h5>Overview:</h5>
5326
5327<p>
5328The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5329</p>
5330
5331<h5>Arguments:</h5>
5332
5333<p>
5334The argument and return value are floating point numbers of the same type.
5335</p>
5336
5337<h5>Semantics:</h5>
5338
5339<p>
5340This function returns the cosine of the specified operand, returning the
5341same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +00005342conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +00005343</div>
5344
5345<!-- _______________________________________________________________________ -->
5346<div class="doc_subsubsection">
5347 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5348</div>
5349
5350<div class="doc_text">
5351
5352<h5>Syntax:</h5>
5353<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5354floating point or vector of floating point type. Not all targets support all
5355types however.
5356<pre>
5357 declare float @llvm.pow.f32(float %Val, float %Power)
5358 declare double @llvm.pow.f64(double %Val, double %Power)
5359 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5360 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5361 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5362</pre>
5363
5364<h5>Overview:</h5>
5365
5366<p>
5367The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5368specified (positive or negative) power.
5369</p>
5370
5371<h5>Arguments:</h5>
5372
5373<p>
5374The second argument is a floating point power, and the first is a value to
5375raise to that power.
5376</p>
5377
5378<h5>Semantics:</h5>
5379
5380<p>
5381This function returns the first value raised to the second power,
5382returning the
5383same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +00005384conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +00005385</div>
5386
Chris Lattner33b73f92006-09-08 06:34:02 +00005387
Andrew Lenharth1d463522005-05-03 18:01:48 +00005388<!-- ======================================================================= -->
5389<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +00005390 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +00005391</div>
5392
5393<div class="doc_text">
5394<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +00005395LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005396These allow efficient code generation for some algorithms.
5397</p>
5398
5399</div>
5400
5401<!-- _______________________________________________________________________ -->
5402<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +00005403 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +00005404</div>
5405
5406<div class="doc_text">
5407
5408<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +00005409<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth7132e002007-08-04 01:51:18 +00005410type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman0f223bb2006-01-13 23:26:38 +00005411<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +00005412 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5413 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5414 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +00005415</pre>
5416
5417<h5>Overview:</h5>
5418
5419<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +00005420The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +00005421values with an even number of bytes (positive multiple of 16 bits). These are
5422useful for performing operations on data that is not in the target's native
5423byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +00005424</p>
5425
5426<h5>Semantics:</h5>
5427
5428<p>
Chandler Carruth7132e002007-08-04 01:51:18 +00005429The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005430and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5431intrinsic returns an i32 value that has the four bytes of the input i32
5432swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth7132e002007-08-04 01:51:18 +00005433i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5434<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +00005435additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +00005436</p>
5437
5438</div>
5439
5440<!-- _______________________________________________________________________ -->
5441<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +00005442 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +00005443</div>
5444
5445<div class="doc_text">
5446
5447<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +00005448<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
5449width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005450<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +00005451 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5452 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005453 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +00005454 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5455 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +00005456</pre>
5457
5458<h5>Overview:</h5>
5459
5460<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +00005461The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5462value.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005463</p>
5464
5465<h5>Arguments:</h5>
5466
5467<p>
Chris Lattner573f64e2005-05-07 01:46:40 +00005468The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +00005469integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005470</p>
5471
5472<h5>Semantics:</h5>
5473
5474<p>
5475The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5476</p>
5477</div>
5478
5479<!-- _______________________________________________________________________ -->
5480<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +00005481 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +00005482</div>
5483
5484<div class="doc_text">
5485
5486<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +00005487<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5488integer bit width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005489<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +00005490 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5491 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005492 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +00005493 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5494 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +00005495</pre>
5496
5497<h5>Overview:</h5>
5498
5499<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +00005500The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5501leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005502</p>
5503
5504<h5>Arguments:</h5>
5505
5506<p>
Chris Lattner573f64e2005-05-07 01:46:40 +00005507The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +00005508integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005509</p>
5510
5511<h5>Semantics:</h5>
5512
5513<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005514The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5515in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerb5ebf3d2006-12-31 07:07:53 +00005516of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +00005517</p>
5518</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +00005519
5520
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005521
5522<!-- _______________________________________________________________________ -->
5523<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +00005524 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005525</div>
5526
5527<div class="doc_text">
5528
5529<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +00005530<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5531integer bit width. Not all targets support all bit widths however.
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005532<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +00005533 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5534 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +00005535 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +00005536 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5537 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005538</pre>
5539
5540<h5>Overview:</h5>
5541
5542<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +00005543The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5544trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005545</p>
5546
5547<h5>Arguments:</h5>
5548
5549<p>
5550The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +00005551integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +00005552</p>
5553
5554<h5>Semantics:</h5>
5555
5556<p>
5557The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5558in a variable. If the src == 0 then the result is the size in bits of the type
5559of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5560</p>
5561</div>
5562
Reid Spencer8a5799f2007-04-01 08:27:01 +00005563<!-- _______________________________________________________________________ -->
5564<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +00005565 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +00005566</div>
5567
5568<div class="doc_text">
5569
5570<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +00005571<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer8bc7d952007-04-01 19:00:37 +00005572on any integer bit width.
5573<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +00005574 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5575 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +00005576</pre>
5577
5578<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +00005579<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +00005580range of bits from an integer value and returns them in the same bit width as
5581the original value.</p>
5582
5583<h5>Arguments:</h5>
5584<p>The first argument, <tt>%val</tt> and the result may be integer types of
5585any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +00005586arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +00005587
5588<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +00005589<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +00005590of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5591<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5592operates in forward mode.</p>
5593<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5594right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +00005595only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5596<ol>
5597 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5598 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5599 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5600 to determine the number of bits to retain.</li>
5601 <li>A mask of the retained bits is created by shifting a -1 value.</li>
5602 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
5603</ol>
Reid Spencer70845c02007-05-14 16:14:57 +00005604<p>In reverse mode, a similar computation is made except that the bits are
5605returned in the reverse order. So, for example, if <tt>X</tt> has the value
5606<tt>i16 0x0ACF (101011001111)</tt> and we apply
5607<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5608<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +00005609</div>
5610
Reid Spencer5bf54c82007-04-11 23:23:49 +00005611<div class="doc_subsubsection">
5612 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5613</div>
5614
5615<div class="doc_text">
5616
5617<h5>Syntax:</h5>
5618<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
5619on any integer bit width.
5620<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +00005621 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5622 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer5bf54c82007-04-11 23:23:49 +00005623</pre>
5624
5625<h5>Overview:</h5>
5626<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5627of bits in an integer value with another integer value. It returns the integer
5628with the replaced bits.</p>
5629
5630<h5>Arguments:</h5>
5631<p>The first argument, <tt>%val</tt> and the result may be integer types of
5632any bit width but they must have the same bit width. <tt>%val</tt> is the value
5633whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5634integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5635type since they specify only a bit index.</p>
5636
5637<h5>Semantics:</h5>
5638<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5639of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5640<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5641operates in forward mode.</p>
5642<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5643truncating it down to the size of the replacement area or zero extending it
5644up to that size.</p>
5645<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5646are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5647in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5648to the <tt>%hi</tt>th bit.
Reid Spencer146281c2007-05-14 16:50:20 +00005649<p>In reverse mode, a similar computation is made except that the bits are
5650reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5651<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 +00005652<h5>Examples:</h5>
5653<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +00005654 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +00005655 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5656 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5657 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +00005658 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +00005659</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +00005660</div>
5661
Chris Lattner941515c2004-01-06 05:31:32 +00005662<!-- ======================================================================= -->
5663<div class="doc_subsection">
5664 <a name="int_debugger">Debugger Intrinsics</a>
5665</div>
5666
5667<div class="doc_text">
5668<p>
5669The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5670are described in the <a
5671href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5672Debugging</a> document.
5673</p>
5674</div>
5675
5676
Jim Laskey2211f492007-03-14 19:31:19 +00005677<!-- ======================================================================= -->
5678<div class="doc_subsection">
5679 <a name="int_eh">Exception Handling Intrinsics</a>
5680</div>
5681
5682<div class="doc_text">
5683<p> The LLVM exception handling intrinsics (which all start with
5684<tt>llvm.eh.</tt> prefix), are described in the <a
5685href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5686Handling</a> document. </p>
5687</div>
5688
Tanya Lattnercb1b9602007-06-15 20:50:54 +00005689<!-- ======================================================================= -->
5690<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +00005691 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +00005692</div>
5693
5694<div class="doc_text">
5695<p>
Duncan Sands86e01192007-09-11 14:10:23 +00005696 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +00005697 the <tt>nest</tt> attribute, from a function. The result is a callable
5698 function pointer lacking the nest parameter - the caller does not need
5699 to provide a value for it. Instead, the value to use is stored in
5700 advance in a "trampoline", a block of memory usually allocated
5701 on the stack, which also contains code to splice the nest value into the
5702 argument list. This is used to implement the GCC nested function address
5703 extension.
5704</p>
5705<p>
5706 For example, if the function is
5707 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling252570f2007-09-22 09:23:55 +00005708 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands644f9172007-07-27 12:58:54 +00005709<pre>
Duncan Sands86e01192007-09-11 14:10:23 +00005710 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5711 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5712 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5713 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +00005714</pre>
Bill Wendling252570f2007-09-22 09:23:55 +00005715 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5716 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +00005717</div>
5718
5719<!-- _______________________________________________________________________ -->
5720<div class="doc_subsubsection">
5721 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5722</div>
5723<div class="doc_text">
5724<h5>Syntax:</h5>
5725<pre>
Duncan Sands86e01192007-09-11 14:10:23 +00005726declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +00005727</pre>
5728<h5>Overview:</h5>
5729<p>
Duncan Sands86e01192007-09-11 14:10:23 +00005730 This fills the memory pointed to by <tt>tramp</tt> with code
5731 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +00005732</p>
5733<h5>Arguments:</h5>
5734<p>
5735 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5736 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5737 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +00005738 intrinsic. Note that the size and the alignment are target-specific - LLVM
5739 currently provides no portable way of determining them, so a front-end that
5740 generates this intrinsic needs to have some target-specific knowledge.
5741 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands644f9172007-07-27 12:58:54 +00005742</p>
5743<h5>Semantics:</h5>
5744<p>
5745 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +00005746 dependent code, turning it into a function. A pointer to this function is
5747 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +00005748 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +00005749 before being called. The new function's signature is the same as that of
5750 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5751 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5752 of pointer type. Calling the new function is equivalent to calling
5753 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5754 missing <tt>nest</tt> argument. If, after calling
5755 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5756 modified, then the effect of any later call to the returned function pointer is
5757 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +00005758</p>
5759</div>
5760
5761<!-- ======================================================================= -->
5762<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +00005763 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5764</div>
5765
5766<div class="doc_text">
5767<p>
5768 These intrinsic functions expand the "universal IR" of LLVM to represent
5769 hardware constructs for atomic operations and memory synchronization. This
5770 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +00005771 is aimed at a low enough level to allow any programming models or APIs
5772 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +00005773 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5774 hardware behavior. Just as hardware provides a "universal IR" for source
5775 languages, it also provides a starting point for developing a "universal"
5776 atomic operation and synchronization IR.
5777</p>
5778<p>
5779 These do <em>not</em> form an API such as high-level threading libraries,
5780 software transaction memory systems, atomic primitives, and intrinsic
5781 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5782 application libraries. The hardware interface provided by LLVM should allow
5783 a clean implementation of all of these APIs and parallel programming models.
5784 No one model or paradigm should be selected above others unless the hardware
5785 itself ubiquitously does so.
5786
5787</p>
5788</div>
5789
5790<!-- _______________________________________________________________________ -->
5791<div class="doc_subsubsection">
5792 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5793</div>
5794<div class="doc_text">
5795<h5>Syntax:</h5>
5796<pre>
5797declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5798i1 &lt;device&gt; )
5799
5800</pre>
5801<h5>Overview:</h5>
5802<p>
5803 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5804 specific pairs of memory access types.
5805</p>
5806<h5>Arguments:</h5>
5807<p>
5808 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5809 The first four arguments enables a specific barrier as listed below. The fith
5810 argument specifies that the barrier applies to io or device or uncached memory.
5811
5812</p>
5813 <ul>
5814 <li><tt>ll</tt>: load-load barrier</li>
5815 <li><tt>ls</tt>: load-store barrier</li>
5816 <li><tt>sl</tt>: store-load barrier</li>
5817 <li><tt>ss</tt>: store-store barrier</li>
5818 <li><tt>device</tt>: barrier applies to device and uncached memory also.
5819 </ul>
5820<h5>Semantics:</h5>
5821<p>
5822 This intrinsic causes the system to enforce some ordering constraints upon
5823 the loads and stores of the program. This barrier does not indicate
5824 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5825 which they occur. For any of the specified pairs of load and store operations
5826 (f.ex. load-load, or store-load), all of the first operations preceding the
5827 barrier will complete before any of the second operations succeeding the
5828 barrier begin. Specifically the semantics for each pairing is as follows:
5829</p>
5830 <ul>
5831 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5832 after the barrier begins.</li>
5833
5834 <li><tt>ls</tt>: All loads before the barrier must complete before any
5835 store after the barrier begins.</li>
5836 <li><tt>ss</tt>: All stores before the barrier must complete before any
5837 store after the barrier begins.</li>
5838 <li><tt>sl</tt>: All stores before the barrier must complete before any
5839 load after the barrier begins.</li>
5840 </ul>
5841<p>
5842 These semantics are applied with a logical "and" behavior when more than one
5843 is enabled in a single memory barrier intrinsic.
5844</p>
5845<p>
5846 Backends may implement stronger barriers than those requested when they do not
5847 support as fine grained a barrier as requested. Some architectures do not
5848 need all types of barriers and on such architectures, these become noops.
5849</p>
5850<h5>Example:</h5>
5851<pre>
5852%ptr = malloc i32
5853 store i32 4, %ptr
5854
5855%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5856 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5857 <i>; guarantee the above finishes</i>
5858 store i32 8, %ptr <i>; before this begins</i>
5859</pre>
5860</div>
5861
Andrew Lenharth95528942008-02-21 06:45:13 +00005862<!-- _______________________________________________________________________ -->
5863<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +00005864 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +00005865</div>
5866<div class="doc_text">
5867<h5>Syntax:</h5>
5868<p>
Mon P Wang2c839d42008-07-30 04:36:53 +00005869 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5870 any integer bit width and for different address spaces. Not all targets
5871 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +00005872
5873<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00005874declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5875declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5876declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5877declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +00005878
5879</pre>
5880<h5>Overview:</h5>
5881<p>
5882 This loads a value in memory and compares it to a given value. If they are
5883 equal, it stores a new value into the memory.
5884</p>
5885<h5>Arguments:</h5>
5886<p>
Mon P Wang6a490372008-06-25 08:15:39 +00005887 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +00005888 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5889 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5890 this integer type. While any bit width integer may be used, targets may only
5891 lower representations they support in hardware.
5892
5893</p>
5894<h5>Semantics:</h5>
5895<p>
5896 This entire intrinsic must be executed atomically. It first loads the value
5897 in memory pointed to by <tt>ptr</tt> and compares it with the value
5898 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5899 loaded value is yielded in all cases. This provides the equivalent of an
5900 atomic compare-and-swap operation within the SSA framework.
5901</p>
5902<h5>Examples:</h5>
5903
5904<pre>
5905%ptr = malloc i32
5906 store i32 4, %ptr
5907
5908%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +00005909%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +00005910 <i>; yields {i32}:result1 = 4</i>
5911%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5912%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5913
5914%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +00005915%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +00005916 <i>; yields {i32}:result2 = 8</i>
5917%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5918
5919%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5920</pre>
5921</div>
5922
5923<!-- _______________________________________________________________________ -->
5924<div class="doc_subsubsection">
5925 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5926</div>
5927<div class="doc_text">
5928<h5>Syntax:</h5>
5929
5930<p>
5931 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5932 integer bit width. Not all targets support all bit widths however.</p>
5933<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00005934declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5935declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5936declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5937declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +00005938
5939</pre>
5940<h5>Overview:</h5>
5941<p>
5942 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5943 the value from memory. It then stores the value in <tt>val</tt> in the memory
5944 at <tt>ptr</tt>.
5945</p>
5946<h5>Arguments:</h5>
5947
5948<p>
Mon P Wang6a490372008-06-25 08:15:39 +00005949 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +00005950 <tt>val</tt> argument and the result must be integers of the same bit width.
5951 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5952 integer type. The targets may only lower integer representations they
5953 support.
5954</p>
5955<h5>Semantics:</h5>
5956<p>
5957 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
5958 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
5959 equivalent of an atomic swap operation within the SSA framework.
5960
5961</p>
5962<h5>Examples:</h5>
5963<pre>
5964%ptr = malloc i32
5965 store i32 4, %ptr
5966
5967%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +00005968%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +00005969 <i>; yields {i32}:result1 = 4</i>
5970%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5971%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5972
5973%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +00005974%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +00005975 <i>; yields {i32}:result2 = 8</i>
5976
5977%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
5978%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
5979</pre>
5980</div>
5981
5982<!-- _______________________________________________________________________ -->
5983<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +00005984 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +00005985
5986</div>
5987<div class="doc_text">
5988<h5>Syntax:</h5>
5989<p>
Mon P Wang6a490372008-06-25 08:15:39 +00005990 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth95528942008-02-21 06:45:13 +00005991 integer bit width. Not all targets support all bit widths however.</p>
5992<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00005993declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
5994declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
5995declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
5996declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +00005997
5998</pre>
5999<h5>Overview:</h5>
6000<p>
6001 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6002 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6003</p>
6004<h5>Arguments:</h5>
6005<p>
6006
6007 The intrinsic takes two arguments, the first a pointer to an integer value
6008 and the second an integer value. The result is also an integer value. These
6009 integer types can have any bit width, but they must all have the same bit
6010 width. The targets may only lower integer representations they support.
6011</p>
6012<h5>Semantics:</h5>
6013<p>
6014 This intrinsic does a series of operations atomically. It first loads the
6015 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6016 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6017</p>
6018
6019<h5>Examples:</h5>
6020<pre>
6021%ptr = malloc i32
6022 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +00006023%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +00006024 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006025%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +00006026 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006027%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +00006028 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +00006029%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +00006030</pre>
6031</div>
6032
Mon P Wang6a490372008-06-25 08:15:39 +00006033<!-- _______________________________________________________________________ -->
6034<div class="doc_subsubsection">
6035 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6036
6037</div>
6038<div class="doc_text">
6039<h5>Syntax:</h5>
6040<p>
6041 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang2c839d42008-07-30 04:36:53 +00006042 any integer bit width and for different address spaces. Not all targets
6043 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +00006044<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006045declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6046declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6047declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6048declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006049
6050</pre>
6051<h5>Overview:</h5>
6052<p>
6053 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6054 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6055</p>
6056<h5>Arguments:</h5>
6057<p>
6058
6059 The intrinsic takes two arguments, the first a pointer to an integer value
6060 and the second an integer value. The result is also an integer value. These
6061 integer types can have any bit width, but they must all have the same bit
6062 width. The targets may only lower integer representations they support.
6063</p>
6064<h5>Semantics:</h5>
6065<p>
6066 This intrinsic does a series of operations atomically. It first loads the
6067 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6068 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6069</p>
6070
6071<h5>Examples:</h5>
6072<pre>
6073%ptr = malloc i32
6074 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +00006075%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +00006076 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006077%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +00006078 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006079%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +00006080 <i>; yields {i32}:result3 = 2</i>
6081%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6082</pre>
6083</div>
6084
6085<!-- _______________________________________________________________________ -->
6086<div class="doc_subsubsection">
6087 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6088 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6089 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6090 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6091
6092</div>
6093<div class="doc_text">
6094<h5>Syntax:</h5>
6095<p>
6096 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6097 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +00006098 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6099 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +00006100<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006101declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6102declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6103declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6104declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006105
6106</pre>
6107
6108<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006109declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6110declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6111declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6112declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006113
6114</pre>
6115
6116<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006117declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6118declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6119declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6120declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006121
6122</pre>
6123
6124<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006125declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6126declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6127declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6128declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006129
6130</pre>
6131<h5>Overview:</h5>
6132<p>
6133 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6134 the value stored in memory at <tt>ptr</tt>. It yields the original value
6135 at <tt>ptr</tt>.
6136</p>
6137<h5>Arguments:</h5>
6138<p>
6139
6140 These intrinsics take two arguments, the first a pointer to an integer value
6141 and the second an integer value. The result is also an integer value. These
6142 integer types can have any bit width, but they must all have the same bit
6143 width. The targets may only lower integer representations they support.
6144</p>
6145<h5>Semantics:</h5>
6146<p>
6147 These intrinsics does a series of operations atomically. They first load the
6148 value stored at <tt>ptr</tt>. They then do the bitwise operation
6149 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6150 value stored at <tt>ptr</tt>.
6151</p>
6152
6153<h5>Examples:</h5>
6154<pre>
6155%ptr = malloc i32
6156 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +00006157%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +00006158 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006159%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +00006160 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006161%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +00006162 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006163%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +00006164 <i>; yields {i32}:result3 = FF</i>
6165%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6166</pre>
6167</div>
6168
6169
6170<!-- _______________________________________________________________________ -->
6171<div class="doc_subsubsection">
6172 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6173 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6174 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6175 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6176
6177</div>
6178<div class="doc_text">
6179<h5>Syntax:</h5>
6180<p>
6181 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6182 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +00006183 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6184 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +00006185 support all bit widths however.</p>
6186<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006187declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6188declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6189declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6190declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006191
6192</pre>
6193
6194<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006195declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6196declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6197declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6198declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006199
6200</pre>
6201
6202<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006203declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6204declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6205declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6206declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006207
6208</pre>
6209
6210<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +00006211declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6212declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6213declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6214declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +00006215
6216</pre>
6217<h5>Overview:</h5>
6218<p>
6219 These intrinsics takes the signed or unsigned minimum or maximum of
6220 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6221 original value at <tt>ptr</tt>.
6222</p>
6223<h5>Arguments:</h5>
6224<p>
6225
6226 These intrinsics take two arguments, the first a pointer to an integer value
6227 and the second an integer value. The result is also an integer value. These
6228 integer types can have any bit width, but they must all have the same bit
6229 width. The targets may only lower integer representations they support.
6230</p>
6231<h5>Semantics:</h5>
6232<p>
6233 These intrinsics does a series of operations atomically. They first load the
6234 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6235 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6236 the original value stored at <tt>ptr</tt>.
6237</p>
6238
6239<h5>Examples:</h5>
6240<pre>
6241%ptr = malloc i32
6242 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +00006243%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +00006244 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006245%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +00006246 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006247%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +00006248 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +00006249%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +00006250 <i>; yields {i32}:result3 = 8</i>
6251%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6252</pre>
6253</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +00006254
6255<!-- ======================================================================= -->
6256<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +00006257 <a name="int_general">General Intrinsics</a>
6258</div>
6259
6260<div class="doc_text">
6261<p> This class of intrinsics is designed to be generic and has
6262no specific purpose. </p>
6263</div>
6264
6265<!-- _______________________________________________________________________ -->
6266<div class="doc_subsubsection">
6267 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6268</div>
6269
6270<div class="doc_text">
6271
6272<h5>Syntax:</h5>
6273<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +00006274 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 +00006275</pre>
6276
6277<h5>Overview:</h5>
6278
6279<p>
6280The '<tt>llvm.var.annotation</tt>' intrinsic
6281</p>
6282
6283<h5>Arguments:</h5>
6284
6285<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +00006286The first argument is a pointer to a value, the second is a pointer to a
6287global string, the third is a pointer to a global string which is the source
6288file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +00006289</p>
6290
6291<h5>Semantics:</h5>
6292
6293<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +00006294This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +00006295This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +00006296annotations. These have no other defined use, they are ignored by code
6297generation and optimization.
6298</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +00006299</div>
6300
Tanya Lattner293c0372007-09-21 22:59:12 +00006301<!-- _______________________________________________________________________ -->
6302<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +00006303 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +00006304</div>
6305
6306<div class="doc_text">
6307
6308<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +00006309<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6310any integer bit width.
6311</p>
Tanya Lattner293c0372007-09-21 22:59:12 +00006312<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +00006313 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6314 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6315 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6316 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6317 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 +00006318</pre>
6319
6320<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +00006321
6322<p>
6323The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +00006324</p>
6325
6326<h5>Arguments:</h5>
6327
6328<p>
6329The first argument is an integer value (result of some expression),
6330the second is a pointer to a global string, the third is a pointer to a global
6331string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +00006332It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +00006333</p>
6334
6335<h5>Semantics:</h5>
6336
6337<p>
6338This intrinsic allows annotations to be put on arbitrary expressions
6339with arbitrary strings. This can be useful for special purpose optimizations
6340that want to look for these annotations. These have no other defined use, they
6341are ignored by code generation and optimization.
6342</div>
Jim Laskey2211f492007-03-14 19:31:19 +00006343
Anton Korobeynikov06cbb652008-01-15 22:31:34 +00006344<!-- _______________________________________________________________________ -->
6345<div class="doc_subsubsection">
6346 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6347</div>
6348
6349<div class="doc_text">
6350
6351<h5>Syntax:</h5>
6352<pre>
6353 declare void @llvm.trap()
6354</pre>
6355
6356<h5>Overview:</h5>
6357
6358<p>
6359The '<tt>llvm.trap</tt>' intrinsic
6360</p>
6361
6362<h5>Arguments:</h5>
6363
6364<p>
6365None
6366</p>
6367
6368<h5>Semantics:</h5>
6369
6370<p>
6371This intrinsics is lowered to the target dependent trap instruction. If the
6372target does not have a trap instruction, this intrinsic will be lowered to the
6373call of the abort() function.
6374</p>
6375</div>
6376
Chris Lattner2f7c9632001-06-06 20:29:01 +00006377<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +00006378<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +00006379<address>
6380 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6381 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6382 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerb8f816e2008-01-04 04:33:49 +00006383 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +00006384
6385 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +00006386 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +00006387 Last modified: $Date$
6388</address>
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